MedWorm.com provides a medical RSS filtering service. Over 6000 RSS medical sources are combined and output via different filters. This feed contains the latest items from the 'Carbohydrate Research' source. Thu, 09 Feb 2012 09:43:29 +0100 http://www.medworm.com/index.php?rid=5668341&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22264629%26dopt%3DAbstract This study reports the effects of SCOSs with different molecular weights on the degradation of articular cartilage through unregulated collagenase expression. The results indicated that the SCOS II (3-5kDa) effectively inhibited the expressions of collagenases 1 and 3 and thereby prevented TNF-α induced degradation of collagen in human chondrosarcoma cells (SW-1353). Moreover, the signaling cascade responsible for this effect was found as SCOS II mediated suppression of NF-κB activation. Based on these data, it can be concluded that SCOS II prevented collagen degradation by inhibiting collagenases 1 and 3 via suppressing TNF-α induced NF-κB signaling. We suggest that SCOS II can be further studied as a potential candidate for the treatment of arthritis. PMID: 22264629 [PubMed - as ... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=5668341 Sun, 08 Jan 2012 05:00:00 +0100 5668341 http://www.medworm.com/index.php?rid=5668338&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22277540%26dopt%3DAbstract Authors: Nakamura-Tsuruta S, Yasuda M, Nakamura T, Shinoda E, Furuyashiki T, Kakutani R, Takata H, Kato Y, Ashida H Abstract For immunological experiments on glycogens, anti-glycogen antibodies are indispensable to capture, detect, and visualize sugar molecules. An anti-glycogen monoclonal antibody (IV58B6) and newly constructed antibody (ESG1A9mAb) have a common immunoglobulin type (IgM) and binding ability to glycogens, but overall possess different binding features. Therefore, they may prove useful for the construction of an advanced system of quantitative ELISA based on their molecular structures. For this purpose, detailed information on the carbohydrate-specificities of ESG1A9mAb and IV58B6 is first required, but their fine specificities for various types of glycogens have no... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=5668338 Sun, 08 Jan 2012 05:00:00 +0100 5668338 http://www.medworm.com/index.php?rid=5668342&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22264628%26dopt%3DAbstract Authors: Liu J, Tang Y, Wu K, Bi C, Cui Q Abstract The conversion of d-fructose to 5-hydroxymethylfurfural (HMF) on a 1mmol scale was achieved in good yield (68%) using NH(4)Cl as catalyst in isopropanol at 120°C. About 3% of 5-i-propoxymethylfurfural was formed. The reaction in ethanol at 100°C on a 10g scale gave a total yield of HMF and 5-ethoxymethylfurfural of 42%. No mineral acid such as H(2)SO(4) and HCl are required. PMID: 22264628 [PubMed - as supplied by publisher] (Source: Carbohydrate Research) Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=5668342 Thu, 05 Jan 2012 05:00:00 +0100 5668342 http://www.medworm.com/index.php?rid=5668337&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22285512%26dopt%3DAbstract Authors: Smith TN, Hash K, Davey CL, Mills H, Williams H, Kiely DE Abstract The nitric acid oxidation of d-glucose was reinvestigated in an effort to better understand and improve the oxidation and subsequent work up steps. The oxidation was carried out using a computer controlled reactor employing a closed reaction flask under an atmosphere of oxygen which allowed for a catalytic oxidation process with oxygen as the terminal oxidant. Removal of nitric acid from product included the use of both diffusion dialysis and nanofiltration methodologies. Product analysis protocols were developed using ion chromatography. PMID: 22285512 [PubMed - as supplied by publisher] (Source: Carbohydrate Research) Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=5668337 Wed, 04 Jan 2012 05:00:00 +0100 5668337 http://www.medworm.com/index.php?rid=5668340&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22265378%26dopt%3DAbstract Authors: French AD, Johnson GP, Cramer CJ, Csonka GI Abstract Adiabatic ϕ/ψ maps for cellobiose were prepared with B3LYP density functional theory. A mixed basis set was used for minimization, followed with 6-31+G(d) single-point calculations, with and without SMD continuum solvation. Different arrangements of the exocyclic groups (38 starting geometries) were considered for each ϕ/ψ point. The vacuum calculations agreed with earlier computational and experimental results on the preferred gas phase conformation (anti-ϕ(H), syn-ψ(H)), and the results from the solvated calculations were consistent with the (syn ϕ(H)/ψ(H) conformations from condensed phases (crystals or solutions). Results from related studies were compared, and there is substantial dependence on the solvation... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=5668340 Tue, 03 Jan 2012 05:00:00 +0100 5668340 http://www.medworm.com/index.php?rid=5668339&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22269981%26dopt%3DAbstract Authors: da Rocha DR, Santos WC, Lima ES, Ferreira VF Abstract Ten new 1,2,3-triazole glycoconjugates were synthesized from d-glucose and evaluated in in vitro assays for their ability to inhibit the enzyme α-glucosidase. Most of the compounds had low activity or were inactive when compared with acarbose. However, the derivative 1,2-O-isopropylidene-3-phenyl-5-(4-phenyl-1H-1,2,3-triazole-1-yl)-α-d-ribofuranose (19i) possessed activity comparable with the standard drug. The influence of the phenyl group on carbon 3 of the carbohydrate framework is discussed. PMID: 22269981 [PubMed - as supplied by publisher] (Source: Carbohydrate Research) Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=5668339 Tue, 03 Jan 2012 05:00:00 +0100 5668339 http://www.medworm.com/index.php?rid=5617770&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22261278%26dopt%3DAbstract Authors: Kuttel M, Ravenscroft N, Foschiatti M, Cescutti P, Rizzo R Abstract Inquilinus limosus is a multi-resistant bacterium found in the respiratory tract of patients with cystic fibrosis. This bacterium produces two unique fully pyruvylated exopolysaccharides in similar quantities: an α-(1→2)-linked mannan and a β-(1→3)-linked glucan. We employed molecular modelling methods to probe the characteristic conformations and dynamics of these polysaccharides, with corroboration from potentiometric titrations and circular dichroism experiments. Our calculations reveal different structural motifs for the mannan and glucan polysaccharides: the glucan forms primarily right-handed helices with a wide range of extensions, while the mannan forms only left-handed helices. This finding ... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=5617770 Tue, 03 Jan 2012 05:00:00 +0100 5617770 http://www.medworm.com/index.php?rid=5617771&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22244339%26dopt%3DAbstract Authors: Hayes JA, Eccles KS, Lawrence SE, Moynihan HA Abstract The synthesis and crystallisation of the pharmaceutically important metabolite, paracetamol-O-glucuronide, is described. Hydrated and anhydrous forms of the target molecule have been characterised by PXRD, DSC and TGA. In addition, a methanol solvate has been analysed, including single crystal analysis, which represents the first structure solution for this system. PMID: 22244339 [PubMed - as supplied by publisher] (Source: Carbohydrate Research) Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=5617771 Thu, 29 Dec 2011 05:00:00 +0100 5617771 http://www.medworm.com/index.php?rid=5469540&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22088883%26dopt%3DAbstract Authors: Rasmussen TS, Jensen HH Abstract Calystegine A(3) is a naturally occurring nortropane iminosugar of which there previously have been three total syntheses. Inspired by our previous work we here report on a fourth approach using 17 steps from 2-deoxy-d-glucose applying a diastereoselective allylation protocol. PMID: 22088883 [PubMed - in process] (Source: Carbohydrate Research) Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=5469540 Sun, 04 Dec 2011 09:00:31 +0100 5469540 http://www.medworm.com/index.php?rid=5469539&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22088884%26dopt%3DAbstract Authors: Khodair AI, Gesson JP Abstract N- and S-galactosylation was carried out via the reaction of 5-((Z)-arylidene)-2-thioxo-4-thiazolidinones with 2,3,4,6-tetra-O-acetyl-α-d-galactopyranosyl bromide under alkaline conditions or under silylation conditions. Deacetylation of the N-galactosylation products was performed with concentrated hydrochloric acid in methanol (3.5%) or sodium methoxide in methanol without cleavage of the 2-thioxo-4-thaizolidinone ring by means of acid hydrolysis. The anomers were separated by flash column chromatography, and their configurations were assigned by NMR spectroscopy. The deprotected nucleosides were screened against leukemia L-1210 and were found inactive. PMID: 22088884 [PubMed - in process] (Source: Carbohydrate Research) Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=5469539 Sun, 04 Dec 2011 09:00:22 +0100 5469539 http://www.medworm.com/index.php?rid=5469538&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22088885%26dopt%3DAbstract Authors: Hashim R, Mirzadeh SM, Heidelberg T, Minamikawa H, Yoshiaki T, Sugimura A Abstract Anomers and epimers α- and β-gluco and -galactosides are expected to behave differently. However, recent results on a series of Guerbet glycosides have indicated similar liquid crystal clearing temperatures for pure β-glucosides and the corresponding α-galactosides. This observation has led to speculation on similarities in the self-assembly interactions between the two systems, attributed to the trans-configuration of the 4-OH group and the hydrophobic aglycon. Previous simulations on related bilayers systems support this hypothesis, by relating this clearing transition temperature to intralayer (sugar-sugar) hydrogen bonding. In order to confirm the hypothesis, the comparison was expan... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=5469538 Sun, 04 Dec 2011 09:00:12 +0100 5469538 http://www.medworm.com/index.php?rid=5372921&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21978611%26dopt%3DAbstract Authors: Ovchinnikova OG, Kocharova NA, Kondakova AN, Bialczak-Kokot M, Shashkov AS, Knirel YA, Rozalski A Abstract An O-polysaccharide and oligosaccharides were isolated by GPC following mild acid degradation of the lipopolysaccharide of Providencia alcalifaciens O28. The O-polysaccharide was studied by sugar and methylation analyses, (1)H and (13)C NMR spectroscopy, including 2D ROESY and H-detected (1)H,(13)C HSQC and HMBC experiments, and the following structure of the branched pentasaccharide repeating unit was established: This structure was confirmed by ESI MS of the isolated tridecasaccharide consisting of the lipopolysaccharide core and one O-polysaccharide repeat. The ESI mass spectrum also enabled inferring the composition of the core oligosaccharide. PMID: 21978611 ... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=5372921 Fri, 04 Nov 2011 14:28:55 +0100 5372921 http://www.medworm.com/index.php?rid=5372920&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21982463%26dopt%3DAbstract Authors: Khan AT, Ali S, Sidick Basha R, Khan MM, Lal M Abstract A wide variety of dithioacetal derivatives of sugars can be cleaved easily into the corresponding open-chain aldehydo sugars using an efficient combination of VO(acac)(2)/H(2)O(2)/NaI at 0-5°C. Some of the salient features of this protocol are mild reaction conditions, good yields, short reaction times, easy work-up procedures, and non-involvement of toxic chemicals. PMID: 21982463 [PubMed - in process] (Source: Carbohydrate Research) Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=5372920 Fri, 04 Nov 2011 14:28:34 +0100 5372920 http://www.medworm.com/index.php?rid=5372919&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21983262%26dopt%3DAbstract Authors: Caron V, Willart JF, Lefort R, Derollez P, Danède F, Descamps M Abstract It has been previously reported that α-lactose could be totally amorphized by ball milling. In this paper we report a detailed investigation of the structural and microstructural changes by which this solid state amorphization takes place. The investigations have been performed by Powder X-ray Diffraction, Solid State Nuclear Magnetic Resonance ((13)C CP-MAS) and Differential Scanning Calorimetry. The results reveal the structural complexity of the material in the course of its amorphization so that it cannot be considered as a simple mixture made of a decreasing crystalline fraction and an increasing amorphous fraction. Heating this complexity can give rise to a fully nano-crystalline material. The... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=5372919 Fri, 04 Nov 2011 14:28:13 +0100 5372919 http://www.medworm.com/index.php?rid=5372918&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21996602%26dopt%3DAbstract Authors: Quang TH, Ngan NT, Minh CV, Kiem PV, Thao NP, Tai BH, Nhiem NX, Song SB, Kim YH Abstract Kalopanax pictus (Araliaceae) is a deciduous tree that grows in East Asian countries. Its stem bark and leaves have been used in traditional medicine to treat rheumatic arthritis, neurotic pain, and diabetes mellitus. A phytochemical study on a methanol extract of the stem bark of K. pictus resulted in the isolation of three new compounds, 6β,16α-dihydroxy-hederagenin 3-O-β-d-glucuronopyranoside (1), 3-O-β-d-glucuronopyranosyl-28-O-β-d-glucopyranosyl-6β,16α-dihydroxy-oleanolic acid (2), and 3-O-β-d-galactopyranosyl(1→3)-α-l-arabinopyranosyl hederagenin 28-O-β-d-glucopyranosyl-(1→6)-β-d-glucopyranosyl ester (3), along with eight known compounds (4-11). Their structures we... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=5372918 Fri, 04 Nov 2011 14:27:53 +0100 5372918 http://www.medworm.com/index.php?rid=5372916&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21996604%26dopt%3DAbstract Authors: Okada H, Fukushi E, Yamamori A, Kawazoe N, Onodera S, Kawabata J, Shiomi N Abstract Fermented beverage of plant extracts was prepared from the extracts of approximately 50 types of vegetables and fruits. Natural fermentation was carried out mainly by lactic acid bacteria (Leuconostoc spp.) and yeast (Zygosaccharomyces spp. and Pichia spp.). Two oligosaccharides containing an α-fructofuranoside linkage were detected in this beverage and isolated using carbon-Celite column chromatography and preparative HPLC. The structural confirmation of the saccharides was determined by methylation analysis, MALDI-TOF-MS, and NMR measurements. These saccharides were identified as α-d-fructofuranosyl-(2→6)-d-glucopyranose, which was isolated from a natural source for the first time, an... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=5372916 Fri, 04 Nov 2011 14:27:12 +0100 5372916 http://www.medworm.com/index.php?rid=5372915&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22000160%26dopt%3DAbstract Authors: Fehér K, Matthews RP, Kövér KE, Naidoo KJ, Szilágyi L Abstract The conformations of several β1→β1' diglycosyl disulfides were investigated by NMR and computational methods. Experimental data, such as NOEs, proton-proton and proton-carbon-13 coupling constants, measured for solutions in DMSO, are in good agreement with values obtained by MD simulations in explicit DMSO. The disulfide torsion angles (C1-S-S-C1') preferentially sample values close to either +90° or -90° (+g or -g) and appear as the main metric that determines the conformational behavior of these glycomimetics. There is more conformational freedom around the C1-S and C1'-S' bonds (Φ and Ω torsions, respectively) and population cluster analysis allowed to identify up to four allowed conformational r... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=5372915 Fri, 04 Nov 2011 14:26:52 +0100 5372915 http://www.medworm.com/index.php?rid=5372914&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22000161%26dopt%3DAbstract Authors: Kinfe HH, Mebrahtu FM, Sithole K Abstract NaHSO(4) supported on silica gel catalyses the Ferrier rearrangement reaction of 3,4,6-tri-O-acetyl-d-glucal with alcohols and thiols to give the corresponding 2,3-unsaturated glycosides in high anomeric selectivity and good to excellent yield in short reaction time. PMID: 22000161 [PubMed - in process] (Source: Carbohydrate Research) Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=5372914 Fri, 04 Nov 2011 14:26:32 +0100 5372914 http://www.medworm.com/index.php?rid=5372913&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22000162%26dopt%3DAbstract This study allowed developing a simple, effective 'fingerprinting' protocol for detecting the damage done to mannans by oxidative radicals. PMID: 22000162 [PubMed - in process] (Source: Carbohydrate Research) Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=5372913 Fri, 04 Nov 2011 14:26:12 +0100 5372913 http://www.medworm.com/index.php?rid=5372912&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22000766%26dopt%3DAbstract Authors: Magoń A, Pyda M Abstract The thermal behaviors of α-d-glucose in the melting and glass transition regions were examined utilizing the calorimetric methods of standard differential scanning calorimetry (DSC), standard temperature-modulated differential scanning calorimetry (TMDSC), quasi-isothermal temperature-modulated differential scanning calorimetry (quasi-TMDSC), and thermogravimetric analysis (TGA). The quantitative thermal analyses of experimental data of crystalline and amorphous α-d-glucose were performed based on heat capacities. The total, apparent and reversingheat capacities, and phase transitions were evaluated on heating and cooling. The melting temperature (T(m)) of a crystalline carbohydrate such as α-d-glucose, shows a heating rate dependence, with the... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=5372912 Fri, 04 Nov 2011 14:25:53 +0100 5372912 http://www.medworm.com/index.php?rid=5372905&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22015400%26dopt%3DAbstract Authors: Denton TT, Hardcastle KI, Dowd MK, Kiely DE Abstract d-Glucaric acid was characterized in solution by comparing NMR spectra from the isotopically unlabeled molecule with those from d-glucaric acid labeled with deuterium or carbon-13 atoms. The NMR studies provided unequivocal assignments for all carbon atoms and non-hydroxyl protons of the molecule. The crystal structure of d-glucaric acid was obtained by X-ray diffraction techniques and the structure was a close match to the low energy conformation generated from a Monte-Carlo-based searching protocol employing the mm3 molecular mechanics program. The molecule adopts a bent structure in both the crystalline and computationally generated lowest-energy structure, a conformation that is devoid of destabilizing eclipsed 1,3-h... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=5372905 Fri, 04 Nov 2011 14:23:42 +0100 5372905 http://www.medworm.com/index.php?rid=5372903&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22024567%26dopt%3DAbstract In this study, sulfated polysaccharides were isolated from brown seaweeds Saccharina japonica (formerly named Laminaria) and Undaria pinnatifida and their antitumor activity was tested against human breast cancer T-47D and melanoma SK-MEL-28 cell lines. The sulfated polysaccharide form S. japonica was highly branched partially acetylated sulfated galactofucan, built up of (1→3)-α-l-fucose residues. The sulfated polysaccharide from U. pinnatifida was partially acetylated highly sulfated galactofucan consisting of (1→3)- or (1→3);(1→4)-α-l-fucose residues. Fucoidans from S. japonica and U. pinnatifida distinctly inhibited proliferation and colony formation in both breast cancer and melanoma cell lines in a dose-dependent manner. These results indicated that the use of sulfated poly... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=5372903 Wed, 05 Oct 2011 04:00:00 +0100 5372903 http://www.medworm.com/index.php?rid=5372888&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22036122%26dopt%3DAbstract Authors: Amarasekara AS, Owereh OS, Ezeh B Abstract The effects of adding D(2)SO(4), and p-toluenesulfonic acid-d to D-cellobiose dissolved in D(2)O were investigated at 23°C by plotting (13)C NMR chemical shift changes (Δδ) against the acid to D-cellobiose molar ratio. (13)C Chemical shifts of all 18 carbon signals from α and β anomers of D-cellobiose showed gradual decreases due to increasing acidity in aqueous D(2)SO(4) medium. The C-1 of the α anomer showed a slightly higher response to increasing D(+) concentration in the surrounding. In the aqueous p-toluenesulfonic acid-d medium, C-6' and C-4' carbons of both α, and β anomeric forms of D-cellobiose are significantly affected by increasing the sulfonic acid concentrations, and this may be due to a 1:1 interaction of p... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=5372888 Wed, 05 Oct 2011 04:00:00 +0100 5372888 http://www.medworm.com/index.php?rid=5372883&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22044776%26dopt%3DAbstract Authors: Gu G, Fang M, Du Y Abstract A practical method for the efficient and selective cleavage of chloroacetyl protecting group using tetra-n-butylammonium fluoride (TBAF) in THF solution at rt was disclosed. PMID: 22044776 [PubMed - as supplied by publisher] (Source: Carbohydrate Research) Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=5372883 Wed, 05 Oct 2011 04:00:00 +0100 5372883 http://www.medworm.com/index.php?rid=5372902&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22024568%26dopt%3DAbstract Authors: Kubota D, Macedo OF, Andrade GR, Conegero LS, Almeida LE, Costa NB, Gimenez IF Abstract Here we report the structural characterization, physicochemical study and molecular modeling of the inclusion complex of trimethoprim in randomly methylated beta-cyclodextrin. The phase-solubility diagram obtained at pH 7.0 exhibited a linear behavior for the RAMEB concentrations studied suggesting a 1:1 stoichiometry and absence of aggregation in solution. From stoichiometric determination by the continuous variation method we confirmed a 1:1 stoichiometry. To make a detailed characterization of the inclusion mode, spectroscopic measurements by infrared and 1D and 2D (1)H NMR spectroscopy provided evidence that the inclusion mode is characterized by inclusion of the trimethoxyphenyl ri... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=5372902 Sun, 02 Oct 2011 04:00:00 +0100 5372902 http://www.medworm.com/index.php?rid=5372901&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22024569%26dopt%3DAbstract Authors: Bychowska A, Theilacker C, Czerwicka M, Marszewska K, Huebner J, Holst O, Stepnowski P, Kaczyński Z Abstract Wall teichoic acid (WTA) was isolated from Enterococcus faecium strain U0317 and structurally characterized using (1)H, (13)C, and (31)P NMR spectroscopy, including two-dimensional COSY, TOCSY, ROESY, HMQC, and HMBC experiments. Further compositional determination was undertaken using classical chemical methods and HF treatment followed by GLC and GLC-MS analyses. The repeating unit of WTA consisted of two residues of 2-acetamido-2-deoxy-d-galactose, glycerol (Gro), and phosphate, and has the structure shown below: PMID: 22024569 [PubMed - as supplied by publisher] (Source: Carbohydrate Research) Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=5372901 Sun, 02 Oct 2011 04:00:00 +0100 5372901 http://www.medworm.com/index.php?rid=5372895&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22030461%26dopt%3DAbstract This study demonstrates that the C. albicans cell wall is a dynamic and adaptive organelle, which alters its structural phenotype in response to growth in host-derived media at physiological temperature. PMID: 22030461 [PubMed - as supplied by publisher] (Source: Carbohydrate Research) Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=5372895 Sun, 02 Oct 2011 04:00:00 +0100 5372895 http://www.medworm.com/index.php?rid=5372885&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22036123%26dopt%3DAbstract Authors: Pieretti G, Puopolo G, Carillo S, Zoina A, Lanzetta R, Parrilli M, Evidente A, Corsaro MM Abstract Pseudomonas chlororaphis subsp. aureofaciens strain M71 was isolated from the root of a tomato plant and it was able to control in vivo Fusarium oxysporum f. sp. radicis-lycopersici responsible for the tomato crown and root rot. Recently, strain M71 was evaluated even for its efficacy in controlling Seiridium cardinale, the causal agent of bark canker of common cypress (Cupressus sempervirens L.). Strain M71 ability to persist on the tomato rhizosphere and on the aerial part of cypress plants could be related to the nature of the lipopolysaccharides (LPS) present on the outer membrane and in particular to the O-specific polysaccharide. A neutral O-specific polysaccharide was ... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=5372885 Sun, 02 Oct 2011 04:00:00 +0100 5372885 http://www.medworm.com/index.php?rid=5372882&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22047746%26dopt%3DAbstract Authors: Pohjanlehto H, Setälä H, Kammiovirta K, Harlin A Abstract N,N'-Diallylaldardiamides (DA) were synthesized from galactaric, xylaric, and arabinaric acids, and used as cross-linkers together with xylan (X) derivatives to create new bio-based hydrogels. Birch pulp extracted xylan was derivatized to different degrees of substitution of 1-allyloxy-2-hydroxy-propyl (A) groups combined with 1-butyloxy-2-hydroxy-propyl (B) and/or hydroxypropyl (HP) groups. The hydrogels were prepared in water solution by UV induced free-radical cross-linking polymerization of derivatized xylan polymers without DA cross-linker (xylan derivative hydrogel) or in the presence of 1 or 5wt% of DA cross-linker (DA hydrogel). Commercially available cross-linker (+)-N,N'-diallyltartardiamide (DAT) was al... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=5372882 Sun, 02 Oct 2011 04:00:00 +0100 5372882 http://www.medworm.com/index.php?rid=5372909&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22015167%26dopt%3DAbstract Authors: Langenhan JM, Endo MM, Engle JM, Fukumoto LL, Rogalsky DR, Slevin LK, Fay LR, Lucker RW, Rohlfing JR, Smith KR, Tjaden AE, Werner HM Abstract Cardenolides such as digitoxin have been shown to inhibit cancer cell growth, to reduce cancer metastasis, and to induce apoptosis in tumor cells. Among the most potent digitoxin-based cytotoxins identified to date are MeON-neoglycosides generated via oxyamine neoglycosylation. Here, we report our studies of oxyamine neoglycosylation aimed at facilitating the elucidation of linkage-diversified digitoxin neoglycoside structure-activity relationships. We identified conditions suitable for the convenient synthesis of digitoxin neoglycosides and found that sugar structure, rather than RON-glycosidic linkage, exerts the strongest influenc... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=5372909 Thu, 29 Sep 2011 04:00:00 +0100 5372909 http://www.medworm.com/index.php?rid=5372908&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22015168%26dopt%3DAbstract Authors: Feng J, Hevey R, Ling CC Abstract The total chemical synthesis of a Forssman antigen analog is described. The pentasaccharide contains a functionalized tether which should facilitate future conjugation with immunogenic proteins. We found that the total synthesis can be efficiently achieved by following a convergent 2+3 strategy, and using N-Troc protected GalNAc thioglycoside as a donor. PMID: 22015168 [PubMed - as supplied by publisher] (Source: Carbohydrate Research) Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=5372908 Thu, 29 Sep 2011 04:00:00 +0100 5372908 http://www.medworm.com/index.php?rid=5372917&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21996603%26dopt%3DAbstract Authors: Tapondjou LA, Nyaa LB, Tane P, Ricciutelli M, Quassinti L, Bramucci M, Lupidi G, Ponou BK, Barboni L Abstract Three new triterpenoid saponins, elucidated as 3-O-β-d-glucopyranosyloleanolic acid 28-O-β-d-xylopyranosyl-(1→4)-α-l-rhamnopyranosyl-(1→2)-β-d-xylopyranoside (parkioside A, 1), 3-O-[β-d-apifuranosyl-(1→3)-β-d-glucopyranosyl]oleanolic acid 28-O-[β-d-apifuranosyl-(1→3)-β-d-xylopyranosyl-(1→4)-[α-l-rhamnopyranosyl-(1→3)]-α-l-rhamnopyranosyl-(1→2)β-d-xylopyranoside (parkioside B, 2) and 3-O-β-d-glucuronopyranosyl-16α-hydroxyprotobassic acid 28-O-α-l-rhamnopyranosyl-(1→3)-β-d-xylopyranosyl-(1→4)-α-l-rhamnopyranosyl-(1→2)-β-d-xylopyranoside (parkioside C, 3), were isolated from the n-BuOH extract of the root bark of Butyrospermum park... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=5372917 Sat, 24 Sep 2011 04:00:00 +0100 5372917 http://www.medworm.com/index.php?rid=5372907&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22015169%26dopt%3DAbstract Authors: Damljanović I, Stevanović D, Vukićević M, Vukićević RD Abstract Peracetylated glycals-3,4,5-tri-O-acetyl-d-glucal (1a), 3,4,5-tri-O-acetyl-d-galactal (1b) and 3,4-di-O-acetyl-6-deoxy-l-glucal (1c)-have been bromochlorinated by a suitable halogenating agent, generated electrochemically from a mixture of bromides and chlorides in dichloromethane. The reaction was performed in two ways: (i) by a constant current electrolysis (2Fmol(-1)) of bromides and substrates in a milieu containing an excess of chlorides (Br(⦵)/1/Cl(⦵)=1:1:6.8) and (ii) by anodic generation of free chlorine from chlorides (2Fmol(-1)) and subsequent addition of bromides and substrates in a ratio Br(⦵)/1=1:1. The corresponding 2-bromo-2-deoxy-glycopyranosyl chlorides were obtained in high yields... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=5372907 Sat, 24 Sep 2011 04:00:00 +0100 5372907 http://www.medworm.com/index.php?rid=5372906&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22015170%26dopt%3DAbstract We report here RPIP-LC and LC-MS methods that enable the synthesis, separation, and characterization of amphiphilic N-arylacyl O-sulfonated aminoglycosides, which are being pursued as small-molecule glycosaminoglycan mimics. The methods described in this work for separating and characterizing these amphiphilic saccharides are further applied to a number of uses: monitoring the progression of sulfonation reactions with analytical RP-HPLC, characterizing sulfate content for individual molecules with ESI-MS, determining the degree of sulfation for products having mixed degrees of sulfation with HPLC and LC-MS, and purifying products with benchtop C18 column chromatography. We believe that the methods described here will be broadly applicable to enabling the synthesis, separation, and characte... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=5372906 Sat, 24 Sep 2011 04:00:00 +0100 5372906 http://www.medworm.com/index.php?rid=5372904&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22015401%26dopt%3DAbstract Authors: Perepelov AV, Zhu H, Senchenkova SN, Wang Q, Shashkov AS, Wang L, Knirel YA Abstract The O-polysaccharide (O-antigen) of Escherichia coli O19ab was studied by sugar analysis along with 1D and 2D (1)H and (13)C NMR spectroscopy. The following structure of the linear pentasaccharide repeating unit was established: where the degree of O-acetylation of GlcNAc is ∼33%. The O-antigen gene cluster of E. coli O19ab was sequenced. The gene functions were tentatively assigned by comparison with sequences in the available databases and found to be in full agreement with the E. coli O19ab-antigen structure. PMID: 22015401 [PubMed - as supplied by publisher] (Source: Carbohydrate Research) Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=5372904 Sat, 24 Sep 2011 04:00:00 +0100 5372904 http://www.medworm.com/index.php?rid=5372889&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22036121%26dopt%3DAbstract Authors: Ren L, Cao X, Geng P, Bai F, Bai G Abstract In humans, both the N-terminal catalytic domain (NtMGAM) and the C-terminal catalytic domain (CtMGAM) of small intestinal maltase glucoamylase (MGAM) are α-glycosidases that catalyze the hydrolysis of α-(1→4) glycosidic linkages in the process of starch digestion, and are considered to be the main therapeutic targets for type 2 diabetes. In this work, recombinant human CtMGAM has been cloned for the first time, and this, combined with the expression of NtMGAM in Pichia pastoris, made it possible for us to study the catalytic mechanism of MGAM in a well-defined system. The enzymatic kinetic assays of the two catalytic domains suggest that CtMGAM has the higher affinity for longer maltose oligosaccharides. Kinetic studies of co... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=5372889 Sat, 24 Sep 2011 04:00:00 +0100 5372889 http://www.medworm.com/index.php?rid=5372911&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22000767%26dopt%3DAbstract Authors: Leivers S, Hidalgo-Cantabrana C, Robinson G, Margolles A, Ruas-Madiedo P, Laws AP Abstract The bile adapted strain Bifidobacterium animalis subsp. lactis IPLA-R1 secretes a high molecular weight exopolysaccharide (HMW-EPS) when grown on the surface of agar-MRSC. This EPS is composed of l-rhamnopyranosyl, d-glucopyranosyl, d-galactopyranosyl and d-galactofuranosyl residues in the ratio of 3:1:1:1. Linkage analysis and 1D and 2D NMR spectroscopy were used to show that the EPS has a hexasaccharide repeating unit with the following structure: Treatment of the EPS with mild acid cleanly removed the terminal d-galactofuranosyl residue. The eps cluster sequenced for strain IPLA-R1 showed high genetic homology with putative eps clusters annotated in the genomes of strains from the... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=5372911 Thu, 22 Sep 2011 04:00:00 +0100 5372911 http://www.medworm.com/index.php?rid=5372910&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22004572%26dopt%3DAbstract Authors: Rachocki A, Pogorzelec-Glaser K, Pawlaczyk C, Tritt-Goc J Abstract The present paper describes a preparation method and molecular investigations of new biodegradable proton-conducting carbohydrate polymer films based on alginic acid and benzimidazole. Electric conductivity was studied in a wide temperature range in order to check the potential application of these compounds as membranes for electrochemical devices. Compared to pure alginic acid powder or its film, the biodegradable film of alginic acid with an addition of benzimidazole exhibits considerably higher conductivity in the range above water boiling temperature (up to approximately 10(-3)S/cm at 473K). Due to this important feature the obtained films can be considered as candidates for application in high-tempera... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=5372910 Thu, 22 Sep 2011 04:00:00 +0100 5372910 http://www.medworm.com/index.php?rid=5372877&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22047747%26dopt%3DAbstract Authors: Martina K, Caporaso M, Tagliapietra S, Heropoulos G, Rosati O, Cravotto G Abstract New highly soluble β-aminoalcohol β-cyclodextrin (β-CD) derivatives have been synthesized via nucleophilic epoxide opening reactions with mono-6-amino mono-6-deoxy-permethyl-β-CD and mono-6-amino mono-6-deoxy-β-CD. The binding properties of the β-CD were enhanced by linking aminoalcohol subunits which caused its solubility to improve markedly. The reaction conditions were optimised using microwave irradiation giving moderate-to-good yields with a series of epoxides. A regioselective epoxide opening reaction was observed in the reaction with styrene oxide while the stereoselectivity was strictly dependent on substrate structure. PMID: 22047747 [PubMed - as supplied by publisher] (So... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=5372877 Thu, 22 Sep 2011 04:00:00 +0100 5372877 http://www.medworm.com/index.php?rid=5293170&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21963341%26dopt%3DAbstract Authors: Wu Y, Wang H, Ng TB Abstract The isolation of a dimeric 29.8-kDa lectin (LFL) from dried Lactarius flavidulus fruit bodies is reported herein. The chromatographic procedure utilized comprised anion-exchange chromatography on DEAE-cellulose, cation-exchange chromatography on CM-cellulose, anion-exchange chromatography on SP-Sepharose, and gel filtration by fast protein liquid chromatography on Superdex 75. The hemagglutinating activity of LFL was inhibited by a variety of simple sugars, such as lactose, p-nitrophenyl α-d-glucopyranoside, p-nitrophenyl β-d-glucopyranoside and inositol, and by the polysaccharide inulin. The activity of LFL was stable up to 40°C. There was a precipitous drop in activity when the temperature was elevated to 50°C. Hemagglutinating activity w... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=5293170 Fri, 16 Sep 2011 04:00:00 +0100 5293170 http://www.medworm.com/index.php?rid=5293168&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21974911%26dopt%3DAbstract Authors: Zhang Q, Brumer H, Gren H, Tu Y Abstract The interaction between para-crystalline cellulose and the cross-linking glycan xyloglucan (XG) plays a central role for the strength and extensibility of plant cell walls. The coating of XGs on cellulose surfaces is believed to be one of the most probable interaction patterns. In this work, the effects of explicit water and side chain variation on the adsorption of XGs on cellulose are investigated by means of atomistic molecular dynamics simulations. The adsorption properties are studied in detail for three XGs on cellulose Iβ 1-10 surface in aqueous environment, namely GXXXGXXXG, GXXLGXXXG, and GXXFGXXXG, which differ in the length and composition of one side chain. Our work shows that when water molecules are included in the th... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=5293168 Fri, 16 Sep 2011 04:00:00 +0100 5293168 http://www.medworm.com/index.php?rid=5293171&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21963340%26dopt%3DAbstract Authors: Zong G, Cai X, Liang X, Zhang J, Wang D Abstract A highly efficient strategy for the preparation of a disaccharide-repeating unit of the O-antigenic polysaccharide of Burkholderia pseudomallei strain 304b, and its dimer and trimer, has been developed through a regio- and stereoselective manner using p-methoxylphenyl 2,4,6-tri-O-benzoyl-α-d-glucopyranoside and 3-O-allyloxycarbonyl-2,4-di-O-benzoyl-6-deoxy-α-l-talopyranosyl trichloroacetimidate as the key synthons. The target molecules were equipped with a p-methoxylphenyl handle at the reducing terminus to allow for their further functionalization and attachment to a carrier protein. PMID: 21963340 [PubMed - as supplied by publisher] (Source: Carbohydrate Research) Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=5293171 Fri, 09 Sep 2011 04:00:00 +0100 5293171 http://www.medworm.com/index.php?rid=5293169&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21963342%26dopt%3DAbstract Authors: Maclean LL, Vinogradov E, Pagotto F, Perry MB Abstract Cronobacter turicensis, previously known as Enterobacter sakazakii, is a Gram-negative opportunistic food-borne pathogen that has been reported as a cause of life-threatening neonatal infections. From chemical and physical analyses involving composition analysis, methylation, two-dimensional high-resolution nuclear magnetic resonance, and mass spectrometry methods, the antigenic O-polysaccharide in the smooth-type lipopolysaccharide of C. turicensis (strain HPB 3287) was determined to be a high molecular mass polymer of a repeating pentasaccharide unit composed of d-galactose, d-glucose, 2-acetamido-2-deoxy-d-galactose, and 5,7-diacetamido-3,5,7,9-tetradeoxy-d-glycero-d-galacto-non-2-ulosonic acid (legionaminic acid), ... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=5293169 Fri, 09 Sep 2011 04:00:00 +0100 5293169 http://www.medworm.com/index.php?rid=5272299&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21945384%26dopt%3DAbstract Authors: Eskandani Z, Huin C, Guégan P Abstract The selective modification of cyclodextrins remains a real challenge to obtain well-defined structures. The targeted cycloheptakis-(1→4)-2,6-di-O-hydroxypropyl-3-O-methyl-α-d-glucopyranosyl [per(2,6-di-O-hydroxypropyl-3-O-methyl)-β-CD] was obtained by a three-step procedure. The selective allylation of the hydroxyl functions at the positions 2 and 6 was used as a first step. This reaction was revisited then enlarged to α and γ-CDs to determine new conditions for a one-step synthesis in high yield. The per(2,6-di-O-allyl)-β-CD derivative was then reacted with iodomethane to provide per(2,6-di-O-allyl-3-O-methyl)-β-CD. Oxidative hydroboration of the allyl functions was then carried out in order to obtain a new CD derivative wit... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=5272299 Thu, 08 Sep 2011 04:00:00 +0100 5272299 http://www.medworm.com/index.php?rid=5272298&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21955790%26dopt%3DAbstract Authors: Inoue K, Nishimoto M, Kitaoka M Abstract 2-Acetamido-2-deoxy-d-galactose (GalNAc) is a common monosaccharide found in biologically functional sugar chains, but its availability is often limited due to the lack of abundant natural sources. In order to produce GalNAc from abundantly available sugars, 2-acetamido-2-deoxy-d-glucose (GlcNAc) was converted to GalNAc by a one-pot reaction using three enzymes involved in the galacto-N-biose/lacto-N-biose I pathway of bifidobacteria. Starting the reaction with 600mM GlcNAc, 170mM GalNAc was produced at equilibrium in the presence of catalytic amounts of ATP and UDP-Glc under optimized conditions. GalNAc was separated from GlcNAc using water-eluting cation-exchange chromatography with a commonly available cation-exchange resin. ... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=5272298 Thu, 08 Sep 2011 04:00:00 +0100 5272298 http://www.medworm.com/index.php?rid=5037267&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21723436%26dopt%3DAbstract Authors: Oscarson S, Somsák L PMID: 21723436 [PubMed - in process] (Source: Carbohydrate Research) Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=5037267 Tue, 19 Jul 2011 00:46:10 +0100 5037267 http://www.medworm.com/index.php?rid=5037270&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21722879%26dopt%3DAbstract Authors: Shimura Y, Oh K, Kon M, Yamamoto E, Mizuno Y, Adachi T, Abe T, Tamogami S, Fukushima J, Inamoto T, Tonozuka T Transglycosylation reactions are useful for preserving a specific sugar structure during the synthesis of branched oligosaccharides. We have previously reported a panosyl unit transglycosylation reaction by pullulan-hydrolyzing amylase II (TVA II) cloned from Thermoactinomyces vulgaris R-47 (Tonozuka et al., Carbohydr. Res., 1994, 261, 157-162). The acceptor specificity of the TVA II transglycosylation reaction was investigated using pullulan as the donor and sugar alcohols as the acceptor. TVA II transferred the α-panosyl unit to the C-1 hydroxyl group of meso-erythritol, C-1 and C-2 of xylitol, and C-1 and C-6 of d-sorbitol. TVA II differentiated between the sugar a... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=5037270 Tue, 28 Jun 2011 23:00:00 +0100 5037270 http://www.medworm.com/index.php?rid=5037268&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21722881%26dopt%3DAbstract Authors: Bhunia SK, Dey B, Maity KK, Patra S, Mandal S, Maiti S, Maiti TK, Sikdar SR, Islam SS A water-soluble glucan, isolated from the alkaline extract of the fruit bodies of an edible mushroom, Lentinus squarrosulus (Mont.) Singer was found to consist of (1→3,6)-linked, (1→3)-linked, (1→6)-linked, and terminal β-d-glucopyranosyl moieties in a relative proportion of approximately 1:2:1:1. This polysaccharide showed optimum activation of macrophages as well as splenocytes and thymocytes at 10μg/mL. Structural investigation was carried out using sugar analysis, methylation analysis, periodate oxidation study, and NMR experiments ((1)H, (13)C, DEPT-135, DQF-COSY, TOCSY, NOESY, ROESY, HMQC, and HMBC). On the basis of above-mentioned experiments, the structure of the repeating uni... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=5037268 Tue, 28 Jun 2011 23:00:00 +0100 5037268 http://www.medworm.com/index.php?rid=5037264&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21742314%26dopt%3DAbstract We examined ozonolysis of low-molecular-weight heparins (LMWHs), enoxaparin and logiparin, and heparosan oligo- and polysaccharides for the removal of the nonreducing terminal unsaturated uronate residue. 1D (1)H NMR showed that these ozone-treated polysaccharides retained the same structure as the starting polysaccharide, except that the C4-C5 double bond in the nonreducing end unsaturated uronate had been removed. The anticoagulant activity of the resulting product from enoxaparin and logiparin was comparable to that of the starting material. These results demonstrate that ozonolysis is an important tool for the removal of unsaturated uronate residues from LMWHs and heparosan without modification of the core polysaccharide structure or diminution of anticoagulant activity. This reaction ... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=5037264 Tue, 21 Jun 2011 23:00:00 +0100 5037264 http://www.medworm.com/index.php?rid=5037266&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21741627%26dopt%3DAbstract Authors: Artner D, Stanetty C, Mereiter K, Zamyatina A, Kosma P Methyl l-glycero-α-d-manno-heptopyranoside was synthesized in good yield by a Fischer-type glycosylation of the heptopyranose with methanol in the presence of cation-exchange resin under reflux and microwave conditions, respectively. The compound crystallized from 2-propanol in an orthorhombic lattice of space group P2(1)2(1)2 showing a comparatively porous structure with a 2-dimensional O-H⋯O hydrogen bond network. As model compounds for the side chain domains of the inner core structure of bacterial lipopolysaccharide, l-glycero-α-d-manno-heptopyranosyl-(1→7)-l-glycero-d-manno-heptopyranose and the corresponding disaccharide methyl α-glycoside were prepared. The former compound was generated via glycosylation of a... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=5037266 Mon, 20 Jun 2011 23:00:00 +0100 5037266 http://www.medworm.com/index.php?rid=5037265&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21742313%26dopt%3DAbstract Authors: Li YP, Li ZJ, Meng XB A series of 4,5-substituted chiral γ-lactams were synthesized through a highly diastereoselective addition-rearrangement approach from 2,3-unsaturated sugar lactones. The single-crystal X-ray structure of one product indicated that the sugar ring was attacked from the axial side. Partial reduction of the nitro group produced N-hydroxy-γ-lactams, which were further reduced with TiCl(3) to yield the 4,5-substituted chiral γ-lactams. The absolute configuration of C5 of the γ-lactam was determined by NOESY spectra. PMID: 21742313 [PubMed - as supplied by publisher] (Source: Carbohydrate Research) Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=5037265 Wed, 15 Jun 2011 23:00:00 +0100 5037265 http://www.medworm.com/index.php?rid=5037262&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21742316%26dopt%3DAbstract Authors: Xu X, Duan W, Huang M, Li G A new type of cellulose derivative, cellulose dehydroabietate (CDA), was synthesized by the O-acylation reaction of cellulose with dehydroabietic acid chloride (DHAC) using ionic liquid 1-butyl-3-methylimidazolium bromide ([bmim]Br) as a solvent and 4-dimethyl-aminopyridine (DMAP) as a catalyst. The resulting CDA was characterized by means of FT-IR, X-ray diffraction (XRD), scanning electron microscopy (SEM), thermal gravimetric analysis (TGA), and elemental analysis. Also, some properties of CDA were determined. These results showed that CDA has better solubility, water-repellency, and resistance to acids and bases than raw cellulose, and these properties increase with the DS of CDA. PMID: 21742316 [PubMed - as supplied by publisher] (Source: C... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=5037262 Wed, 15 Jun 2011 23:00:00 +0100 5037262 http://www.medworm.com/index.php?rid=5037261&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21742317%26dopt%3DAbstract Authors: Gong P, Peng S, He J, Deng M, Jiang B, Wang K The synthesis of branched polysaccharides using naturally occurring materials has been reported since 1975, but applications of branched polysaccharides are relatively limited because of the long and complex modification processes. In this work, a practical and efficient procedure is presented that in one step levoglucosan can be grafted to galactomannan (at 115°C for 15h) with monochloroacetic acid as catalyst. The structural characteristics of the resulting substances were investigated by NMR spectroscopy. The MS (molar degree of substitution) of glucose was shown to gradually increase with the increase of the ratio of levoglucosan to galactomannan, and the maximal MS is 0.6. Levoglucosan units are mostly grafted to the C6-OH of... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=5037261 Wed, 15 Jun 2011 23:00:00 +0100 5037261 http://www.medworm.com/index.php?rid=5037260&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21742318%26dopt%3DAbstract Authors: Yavuz AG, Uygun A, Kaplan Can H Substituted polyaniline/chitosan (sPANI/Ch) composites were chemically synthesized in H(2)SO(4) and CH(3)COOH synthesis media. Structural and physical properties of the composites were characterized by using FTIR, SEM, TGA, UV-vis, XRD techniques, and conductivity measurements. The effect of synthesis media on morphology, thermal stability, conductivity, and crystalline properties was investigated. Chemical interactions between substituted polyanilines and chitosan were explained using FTIR spectra results. The different morphological surfaces were observed in SEM images of the composites. The size of the substituted polyaniline/chitosan (sPANI/Ch) composites was in nanoscale, and the composites synthesized in acetic acid media showed smaller st... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=5037260 Wed, 15 Jun 2011 23:00:00 +0100 5037260 http://www.medworm.com/index.php?rid=5037263&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21742315%26dopt%3DAbstract Authors: Patra S, Maity KK, Bhunia SK, Dey B, Mandal S, Maiti TK, Sikdar SR, Islam SS A water soluble polysaccharide isolated from the hot aqueous extract of the fruit bodies of the somatic hybrid mushroom (PfloVv1aFB), raised through protoplast fusion between the strains of Pleurotus florida and Volvariella volvacea was found to consist of d-glucose, d-galactose, and d-mannose in a molar ratio of nearly 4:1:1 and showed macrophage, splenocyte, and thymocyte activation. On the basis of sugar analysis, methylation analysis, periodate oxidation, and NMR studies ((1)H, (13)C, DEPT-135, DQF-COSY, TOCSY, NOESY, ROESY, HMQC and HMBC), the structure of the repeating unit of the polysaccharide was established as: PMID: 21742315 [PubMed - as supplied by publisher] (Source: Carbohydrate Rese... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=5037263 Tue, 14 Jun 2011 23:00:00 +0100 5037263 http://www.medworm.com/index.php?rid=5037259&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21745656%26dopt%3DAbstract Authors: Nakagawa T, Nishi Y, Kondo A, Shirai Y, Honda C, Asahi M, Tanimoto T 6(I),6(IV)-Di-O-[α-l-fucopyranosyl-(1→6)-2-acetamido-2-deoxy-β-d-glucopyranosyl]-cyclomaltoheptaose (βCD) {6(I),6(IV)-di-O-[α-l-Fuc-(1→6)-β-d-GlcNAc]-βCD (5)} and 6-O-[α-l-fucopyranosyl-(1→6)-2-acetamido-2-deoxy-β-d-glucopyranosyl]-βCD {6-O-[α-l-Fuc-(1→6)-β-d-GlcNAc]-βCD (6)} were chemically synthesized using the corresponding authentic compounds, bis(2,3-di-O-acetyl)-pentakis(2,3,6-tri-O-acetyl)-βCD as the glycosyl acceptor and 2,3,4-tri-O-benzyl-α-l-fucopyranosyl-(1→6)-3,4-di-O-acetyl-2-deoxy-2-(2,2,2-trichloroethoxycarbonylamino)-d-glucopyranosyl trichloroacetimidate as the fuco-glucosaminyl donor. NMR confirmed that α-l-Fuc-(1→6)-d-GlcNAc was bonded by β-linking to the βCD rin... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=5037259 Tue, 14 Jun 2011 23:00:00 +0100 5037259 http://www.medworm.com/index.php?rid=5037269&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21722880%26dopt%3DAbstract Authors: Meng P, Guo Y, Zhang Q, Hou J, Bai F, Geng P, Bai G A novel amino-oligosaccharide, named SF638-1, was isolated from the culture filtrate of the Streptomyces strain PW638. Its chemical structure was determined by electrospray ionization tandem mass spectrometry (ESI-MS/MS) and two-dimensional nuclear magnetic resonance spectroscopy. The novel compound was a mixed inhibitor of human pancreatic α-amylase, with a K(i) value in the same order of magnitude as that of the α-amylase inhibitor, acarbose. SF638-1 inhibited starch hydrolysis and glucose transfer in vitro, and suppressed postprandial blood glucose elevation in vivo. These results suggest that SF638-1 may be a potent antidiabetic agent. PMID: 21722880 [PubMed - as supplied by publisher] (Source: Carbohydrate Research... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=5037269 Sun, 12 Jun 2011 23:00:00 +0100 5037269 http://www.medworm.com/index.php?rid=4993257&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21714960%26dopt%3DAbstract Authors: Rajasekar M, Khan SM, Devaraj SN, Das TM A series of fluorescein-based N-glycosylamines was synthesized from the corresponding fluorescein amine and a partially protected d-glucose. The physiochemical investigation of these compounds by spectral and morphological studies reveals their gelation potential. The exclusive localization of fluorescence in the cytoplasm through cell imaging studies reveals the anti-cancer potentials of N-glycosylamines. PMID: 21714960 [PubMed - as supplied by publisher] (Source: Carbohydrate Research) Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4993257 Sun, 12 Jun 2011 23:00:00 +0100 4993257 http://www.medworm.com/index.php?rid=4993255&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21718973%26dopt%3DAbstract Authors: Tul'skaya EM, Streshinskaya GM, Shashkov AS, Senchenkova SN, Avtukh AN, Baryshnikova LM, Evtushenko LI Cell walls of each of five bacterial strains belonging to the genus Kribbella (family Nocardioidaceae, order Actinomycetales) contain a neutral polysaccharide (mannan) and teichulosonic acid of novel structure in different proportions. The novel teichulosonic acid found in strains VKM Ac-2500, VKM Ас-2568, VKM Ас-2572, and VKM Ас-2575 is a heteropolymer with an irregular structure where fragments I (predominant) alternate with fragments II (minor): The teichulosonic acid from Kribbella sp. VKM Ac-2527 has in general a structure similar to that above with the exception that the Pse residue is randomly glycosylated at O-4 with β-l-Rhap (along with α-d-Galp3OMe or α-d-G... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4993255 Sun, 12 Jun 2011 23:00:00 +0100 4993255 http://www.medworm.com/index.php?rid=4993258&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21714959%26dopt%3DAbstract Authors: Mugunthan G, Sriram D, Yogeeswari P, Ravindranathan Kartha KP Chiral nitroimidazoles were synthesized using sugars as the chiral source. The synthesized compounds showed promising antimycobacterial property with MIC value in the range 6.25-12.5μg/mL against Mycobacterium tuberculosis H(37)Rv. PMID: 21714959 [PubMed - as supplied by publisher] (Source: Carbohydrate Research) Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4993258 Sun, 05 Jun 2011 23:00:00 +0100 4993258 http://www.medworm.com/index.php?rid=4993254&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21718974%26dopt%3DAbstract Authors: Li N, Wei X, Mei Z, Xiong X, Chen S, Ye M, Ding S A novel insoluble crosslinked copolymer containing β-cyclodextrin (β-CD) structural units has been synthesized with polyamidoamine (PAMAM, generation 2) as comonomer. The polymer was characterized using Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), elemental analysis, scanning electron microscopy (SEM), pores and surface area analysis, X-ray diffraction analysis (XRD), and thermal analysis (thermogravimetric and differential scanning calorimetric measurement, TG/DSC). The results reveal that PAMAM-CD copolymer has been synthesized successfully and two β-CD molecules were cross-linked by one PAMAM (G2.0) molecule (on average). The copolymer has a reef-like surface with many irregular ... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4993254 Sun, 05 Jun 2011 23:00:00 +0100 4993254 http://www.medworm.com/index.php?rid=4993262&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21703597%26dopt%3DAbstract Authors: Martinková M, Gonda J, Pomikalová K, Kožíšek J, Kuchár J A facile synthetic route to d-ribo-C(20)-phytosphingosine 31 and its C2 epimer 32 is described. The Overman rearrangement of allylic trichloroacetimidates derived from the known ribose derivative 7 has been used as the key step. The subsequent functional group interconversions in rearranged products 14 and 15 followed by Wittig olefination, Pd/C-mediated reduction and the removal of protecting groups successfully constructed the final molecules. PMID: 21703597 [PubMed - as supplied by publisher] (Source: Carbohydrate Research) Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4993262 Wed, 01 Jun 2011 23:00:00 +0100 4993262 http://www.medworm.com/index.php?rid=4993261&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21703598%26dopt%3DAbstract In this study, fucoidan was identified during extraction with H(2)SO(4) and HCl; its presence was confirmed by FT-Raman spectroscopy in aqueous solution. In particular, shifts at 840cm(-1) were analysed, which are due to the presence of sulfate at the axial C-4 position, as were the shifts at about 811-809cm(-1), for which the sulfated fucoidan is responsible. Shifts of electrophoretic bands of fucoidan resulting from mild acid hydrolysis in H(2)SO(4) and HCl were also analysed. The analytical procedure was developed using apparatus for cellulose acetate membrane electrophoresis and this was supplemented by semi-quantitative analysis. PMID: 21703598 [PubMed - as supplied by publisher] (Source: Carbohydrate Research) Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4993261 Sun, 29 May 2011 23:00:00 +0100 4993261 http://www.medworm.com/index.php?rid=4993259&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21704310%26dopt%3DAbstract Authors: Li Y, Zhou Y, Ma Y, Li X GlmM and GlmU are key enzymes in the biosynthesis of UDP-N-acetyl-d-glucosamine (UDP-GlcNAc), an essential precursor of peptidoglycan and the rhamnose-GlcNAc linker region in the mycobacterial cell wall. These enzymes are involved in the conversion of two important precursors of UDP-GlcNAc, glucosamine-6-phosphate (GlcN-6-P) and glucosamine-1-phosphate (GlcN-1-P). GlmM converts GlcN-6-P to GlcN-1-P, GlmU is a bifunctional enzyme, whereby GlmU converts GlcN-1-P to GlcNAc-1-P and then catalyzes the formation of UDP-GlcNAc from GlcNAc-1-P and uridine triphosphate. In the present study, methyl 2-amino-2-deoxyl-α-d-glucopyranoside 6-phosphate (1α), methyl 2-amino-2-deoxyl-β-d-glucopyranoside 6-phosphate (1β), two analogs of GlcN-6-P, were synthesized as... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4993259 Sun, 29 May 2011 23:00:00 +0100 4993259 http://www.medworm.com/index.php?rid=4993256&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21718972%26dopt%3DAbstract Authors: Baek WI, Pant HR, Nam KT, Nirmala R, Oh HJ, Kim I, Kim HY Ultrafine fibers of cellulose acetate/poly(butyl acrylate) (CA/PBA) composite in which PBA acted as an adhesive and CA acted as a matrix, were successfully prepared as fibrous mat via electrospinning. The morphology observation from the electrospun CA/PBA composite fibers, after treatment with heat hardener, revealed that the fibers were cylindrical and had point-bonded structures. SEM, FT-IR spectra, Raman spectra, TGA analysis, and mechanical properties measurement were used to study the different properties of hybrid mats. The tensile strength of blend fibrous electrospun mats was found to be effectively increased. This resultant enhancement of the mechanical properties of polymer fibrous mats, caused by generating t... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4993256 Sun, 29 May 2011 23:00:00 +0100 4993256 http://www.medworm.com/index.php?rid=4993266&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21683945%26dopt%3DAbstract Authors: Twelkmeyer B, Burström PK, Li J, Richard Moxon E, Hood DW, Schweda EK The structure of lipopolysaccharide (LPS) expressed by non-typeable Haemophilus influenzae (NTHi) strains 1008 and 1247 has been investigated by mass spectrometry and NMR analyses on O-deacylated LPS and core oligosaccharide material. Both strains express the conserved triheptosyl inner core, [l-α-d-Hepp-(1→2)-[PEtn→6]-l-α-d-Hepp-(1→3)-l-α-d-Hepp-(1→5)-[PPEtn→4]-α-Kdo-(2→6)-Lipid A] with PCho→6)-β-d-Glcp (GlcI) substituting the proximal heptose (HepI) at O-4. Strain 1247 expresses the common structural motifs of H. influenzae; globotetraose [β-d-GalpNAc-(1→3)-α-d-Galp-(1→4)-β-d-Galp-(1→4)-β-d-Glcp-(1→] and its truncated versions globoside [α-d-Galp-(1→4)-β-d-Galp-(1→4)-�... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4993266 Thu, 26 May 2011 23:00:00 +0100 4993266 http://www.medworm.com/index.php?rid=4993264&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21696710%26dopt%3DAbstract Authors: Torpenholt S, Le Nours J, Christensen U, Jahn M, Withers S, Ostergaard PR, Borchert TV, Poulsen JC, Lo Leggio L β-1,4-Galactanases belong to glycoside hydrolase family GH 53 and degrade galactan and arabinogalactan side chains of the complex pectin network in plant cell walls. Two fungal β-1,4-galactanases from Aspergillus aculeatus, Meripileus giganteus and one bacterial enzyme from Bacillus licheniformis have been kinetically characterized using the chromogenic substrate analog 4-nitrophenyl β-1,4-d-thiogalactobioside synthesized by the thioglycoligase approach. Values of k(cat)/K(m) for this substrate with A. aculeatus β-1,4-galactanase at pH 4.4 and for M. giganteus β-1,4-galactanase at pH 5.5 are 333M(-1)s(-1) and 62M(-1)s(-1), respectively. By contrast the B. lichen... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4993264 Thu, 26 May 2011 23:00:00 +0100 4993264 http://www.medworm.com/index.php?rid=4993263&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21700271%26dopt%3DAbstract This study evaluated the deacetylation characteristics of β-chitin from jumbo squid (Dosidicus gigas) pens by using strongly alkaline solutions of NaOH or KOH. Taguchi design was employed to investigate the effect of reagent concentration, temperature, time, and treatment step on molecular mass (MM) and degree of deacetylation (DDA) of the chitosan obtained. The optimal treatment conditions for achieving high MM and DDA of chitosan were identified as: 40% NaOH at 90°C for 6h with three separate steps (2h+2h+2h) or 50% NaOH at 90°C for 6h with one step, or 50% KOH at 90°C for 4h with three steps (1h+1h+2h) or 6h with one step. The most important factor affecting DDA and MM was temperature and time, respectively. The chitosan obtained was then further depolymerized by cellulase or lysozy... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4993263 Thu, 26 May 2011 23:00:00 +0100 4993263 http://www.medworm.com/index.php?rid=4993260&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21704309%26dopt%3DAbstract Authors: Du H, Qian X Quantum mechanical calculations were carried out to determine the mechanisms for the superiority of the imidazolium acetate-based ionic liquids to the corresponding chloride-based ionic liquids. Our results indicate that the imidazolium cation can react with the acetate anion to generate a carbene, a highly reactive intermediate. The carbene produced then reacts with cellulose to facilitate its dissolution in the ionic liquid solvents in addition to the stronger hydrogen bonds formed between the acetate anion and the hydroxyl groups on cellulose. The mechanisms for the imidazolium cation and acetate anion reactions involve the initial ion pairing of the cation and anion via hydrogen bonding and electrostatic interactions. The hydrogen bond formed between the C2-H ... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4993260 Thu, 26 May 2011 23:00:00 +0100 4993260 http://www.medworm.com/index.php?rid=4993265&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21689810%26dopt%3DAbstract Authors: Lewicky JD, Ulanova M, Jiang ZH Bacterial endotoxin lipopolysaccharide (LPS) is a potent immune stimulant, with the recognition of LPS and its active principal lipid A mediated by the Toll-like receptor 4 (TLR4)/MD-2 receptor complex. Due to the broad downstream implications of TLR4-mediated signalling, TLR4 ligands show great potential for immunotherapeutic manipulations. In this paper a dimeric monosaccharide lipid A mimic (3) has been designed as a potential TLR4 ligand. The chemical synthesis and the preliminary biological studies are described. Compound 3 shows a significant synergistic effect on LPS-induced ICAM-1 expression in human monocytic THP-1 cells. PMID: 21689810 [PubMed - as supplied by publisher] (Source: Carbohydrate Research) Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4993265 Wed, 25 May 2011 23:00:00 +0100 4993265 http://www.medworm.com/index.php?rid=4943495&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21645885%26dopt%3DAbstract Authors: Fröhlich RF, Furneaux RH, Mahuran DJ, Saf R, Stütz AE, Tropak MB, Wicki J, Withers SG, Wrodnigg TM Two simple and reliably accessible intermediates, N-carboxypentyl- and N-aminohexyl-1-deoxy-d-galactonojirimycin were employed for the synthesis of a set of terminally N-dansyl substituted derivatives. Reaction of the terminal carboxylic acid of N-carboxypentyl-1-deoxy-d-galactonojirimycin with N-dansyl-1,6-diaminohexane provided the chain-extended fluorescent derivative. Employing bis(6-dansylaminohexyl)amine, the corresponding branched di-N-dansyl compound was obtained. Partially protected N-aminohexyl-1-deoxy-d-galactonojirimycin served as intermediate for two additional chain-extended fluorescent 1-deoxy-d-galactonojirimycin (1-DGJ) derivatives featuring terminal dansyl gro... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4943495 Mon, 23 May 2011 23:00:00 +0100 4943495 http://www.medworm.com/index.php?rid=4943494&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21645886%26dopt%3DAbstract Authors: Ruiz N, Ferreira SS, Padro D, Reichardt NC, Martín-Lomas M The regioselectivity of glycosylation of a 4,6-diol system in the β-mannopyranosyl unit of a N-glycan pentasaccharide core structure is found to be strongly dependent on the structure of the glycosyl donor. While glycosylation with a 2-O-acetyl-d-mannopyranosyl trichloroacetimidate and with a d-mannopyranosyl (α1→3) 2-O-acetyl mannopyranosyl trichoroacetimidate regioselectively occurs at the primary OH-6 position, reaction with d-mannopyranosyl (α1→6) mannopyranosyl 2-O-benzoyl, 2-O-acetyl and 2-O-pivaloyl trichloroacetimidate results in approximately 1:1 mixture of regioisomers at primary OH-6 and secondary OH-4 positions. PMID: 21645886 [PubMed - as supplied by publisher] (Source: Carbohydrate Research) Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4943494 Mon, 23 May 2011 23:00:00 +0100 4943494 http://www.medworm.com/index.php?rid=4943490&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21665197%26dopt%3DAbstract Authors: Choma A, Komaniecka I Periplasmic, cyclic β-glucans isolated from Bradyrhizobium elkanii, Bradyrhizobium liaoningense, and Bradyrhizobium yuanmingense strains have been investigated by means of Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS), 1D and 2D nuclear magnetic resonance (NMR), as well as standard chemical methods. These compounds are built of 10-13 d-glucose residues. The main fractions contain molecules assembled of 12 hexose units (M(w)=1945.363Da). Glucose monomers are linked by β-(1→3) or β-(1→6) glycosidic bonds. The ratio of β-(1→3) to β-(1→6) linked glucose is approximately 1:2. Moreover, methylation analysis demonstrated the presence of terminal, non-reducing, as well as branched (i.e., 3- and 6-substitu... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4943490 Mon, 23 May 2011 23:00:00 +0100 4943490 http://www.medworm.com/index.php?rid=4943492&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21665195%26dopt%3DAbstract Authors: Shashkov AS, Arbatsky NP, Knirel YA Cronobacter sakazakii G2706 and G2704 are the reference strains of serotypes O5 and O6 in the serological classification of this species proposed recently. Mild acid degradation of the lipopolysaccharides of both strains resulted in cleavage of the O-polysaccharide chains at the acid-labile linkage of 3-deoxy-d-manno-oct-2-ulosonic acid (Kdo) to yield oligosaccharides representing repeating units of the O-polysaccharides. The oligosaccharides and alkali-degraded lipopolysaccharides were studied by sugar analysis along with 1D and 2D (1)H and (13)C NMR spectroscopy, and the following O-polysaccharide structures were established: The structure of strain G2706 is unique among the known bacterial polysaccharide structures, whereas that of strain... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4943492 Wed, 18 May 2011 23:00:00 +0100 4943492 http://www.medworm.com/index.php?rid=4943491&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21665196%26dopt%3DAbstract Authors: Tsoukala E, Manta S, Tzioumaki N, Kiritsis C, Komiotis D A novel series of fluorinated keto-β-d-5-thioxylopyranonucleosides bearing thymine as the heterocyclic base have been designed and synthesized. Deprotection of 3-deoxy-3-fluoro-5-S-acetyl-5-thio-d-xylofuranose (1) and selective acetalation gave the desired isopropylidene 5-thioxylopyranose precursor 3. Acetylation and isopropylidene removal followed by benzoylation led to 3-deoxy-3-fluoro-1,2-di-Ο-benzoyl-4-O-acetyl-5'-thio-d-xylopyranose (6). This was condensed with silylated thymine and selectively deacetylated to afford 1-(2'-Ο-benzoyl-3'-deoxy-3'-fluoro-5'-thio-β-d-xylopyranosyl)thymine (8). Oxidation of the free hydroxyl group in the 4'-position of the sugar led to the formation of the target 4'-keto compound to... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4943491 Wed, 18 May 2011 23:00:00 +0100 4943491 http://www.medworm.com/index.php?rid=4943493&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21663897%26dopt%3DAbstract Authors: Kaeothip S, Demchenko AV Traditional strategies for oligosaccharide synthesis often require extensive protecting and/or leaving group manipulations between each glycosylation step, thereby increasing the total number of synthetic steps while decreasing the efficiency of the synthesis. In contrast, expeditious strategies allow for the rapid chemical synthesis of complex carbohydrates by minimizing extraneous chemical manipulations. Oligosaccharide synthesis by selective activation of one leaving group over another is one such expeditious strategy. Herein, the significant improvements that have recently emerged in the area of the selective activation are discussed. The development of orthogonal strategy further expands the scope of the selective activation methodology. Surveyed ... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4943493 Tue, 17 May 2011 23:00:00 +0100 4943493 http://www.medworm.com/index.php?rid=4794138&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21470597%26dopt%3DAbstract Authors: Kanso R, Striegler S We recently proposed to conduct selective glycosylation reactions after in situ activation of a glycosyl donor promoted by a transition metal complex immobilized in a macromolecular matrix. In order to develop this catalytic entity, a feasible multi gram-scale synthesis for 2,3,4,6-tetra-O-benzyl-d-galactothionolactam, its transformation into galactonoamidines with aromatic aglycon, and subsequent debenzylation conditions were developed. The potential for epimerization reactions at C-2 of the glycosidic ring during the transformations from the 2,3,4,6-tetra-O-benzyl-d-galactonolactam into the N-benzyl-2,3,4,6-tetra-O-benzyl-d-galactonoamidines via the 2,3,4,6-tetra-O-benzyl-d-galactothionolactam are discussed and additionally characterized by using density... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4794138 Sat, 07 May 2011 08:15:16 +0100 4794138 http://www.medworm.com/index.php?rid=4794136&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21470598%26dopt%3DAbstract Authors: Hsieh YC, Chir JL, Yang ST, Chen SJ, Hu CH, Wu AT A sugar-aza-crown ether (SAC)-based fluorescent sensor 4 was prepared. It contains a pyrene as the fluorophore and its fluoroionophoric properties toward transition metal ions were investigated. Chemosensor 4 exhibits highly selective recognition toward Cu(2+) and Hg(2+) ions among a series of tested metal ions in methanol solution. The association constants for 4*Cu(2+) and 4*Hg(2+) in methanol solution were calculated to be 7.4×10(1)M(-1) and 4.4×10(3)M(-1), respectively. Chemosensor 4 formed complexes with the Cu(2+) or Hg(2+) ion at a 1:1 ligand-to-metal ratio with a detection limit of 1.3×10(-4)M Cu(2+) and 1.26×10(-5)MHg(2+), respectively. PMID: 21470598 [PubMed - in process] (Source: Carbohydrate Research) Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4794136 Sat, 07 May 2011 08:15:12 +0100 4794136 http://www.medworm.com/index.php?rid=4794135&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21474120%26dopt%3DAbstract Authors: Yudina ON, Gening ML, Tsvetkov YE, Grachev AA, Pier GB, Nifantiev NE A series of five 3-acetamidopropyl β-glycosides of nona-β-(1→6)-glucosamines containing two N-acetylglucosamine residues separated by a different number of glucosamine units with free amino groups have been synthesized using a convergent blockwise approach. Oxazoline glycosylation was used to introduce N-acetylglucosamine residues. These nonasaccharides are structurally related to the poly-N-acetylglucosamine (PNAG) extracellular polysaccharide of Staphylococcus aureus and can be used as models for biochemical and immunological studies. PMID: 21474120 [PubMed - in process] (Source: Carbohydrate Research) Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4794135 Sat, 07 May 2011 08:15:08 +0100 4794135 http://www.medworm.com/index.php?rid=4684863&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21429479%26dopt%3DAbstract Authors: Bera M, Patra A The investigation of the sugar-metal ion interactions remains one of the main objectives of carbohydrate coordination chemistry because the interactions between metal ions and carbohydrates are involved in many biochemical processes. The potential binding interaction between a five-coordinate dinuclear cobalt(II) complex, Na(2)[Co(2)(tcdc)(μ-OAc)] (1) [Na(5)tcdc=Sodium-N,N,N',N'-tetrakis(sodium carboxylate methyl)-2,6-diaminocresolate] and biologically important sugar substrates (d-glucose, d-xylose, and d-mannose) has been studied. In alkaline media, the complex 1 shows an excellent chelating ability toward these sugar substrates. A combined approach of FTIR and UV-vis spectroscopic investigations shows that the complex forms a 1:1 complex/substrate-bound pro... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4684863 Thu, 07 Apr 2011 21:00:30 +0100 4684863 http://www.medworm.com/index.php?rid=4684862&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21439554%26dopt%3DAbstract Authors: Mazzola EP, Parkinson A, Kennelly EJ, Coxon B, Einbond LS, Freedberg DI The structures of three complex saponins from the fruit pods of Blighia sapida have been elucidated and their (1)H and (13)C NMR spectra assigned employing a variety of one- and two-dimensional NMR techniques without degradative chemistry. The saponins have either four or six monosaccharide units linked to a triterpene aglycone. High-resolution, proton-coupled-HSQC spectra were important for determining both the identities of the intact monosaccharide units and coupling constants in strongly coupled proton spin systems. These NMR experiments will prove crucial as the complexity of saponin structures reaches the limit that can be determined solely by NMR. PMID: 21439554 [PubMed - in process] (Source: Ca... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4684862 Thu, 07 Apr 2011 21:00:26 +0100 4684862 http://www.medworm.com/index.php?rid=4684861&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21439555%26dopt%3DAbstract Authors: Nagarajan S, Jeganathan Shanmugam M, Mohan Das T A series of ether-, substituted alkyl-, or aryl-linked disaccharide derivatives have been synthesized in relatively good yield and characterized using different spectral techniques including single-crystal X-ray diffraction (XRD). β-Anomeric forms of sugar moiety in these derivatives were identified from (1)H NMR studies. The existence of inter- and intramolecular hydrogen bonding interactions were identified from single-crystal XRD studies. PMID: 21439555 [PubMed - in process] (Source: Carbohydrate Research) Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4684861 Thu, 07 Apr 2011 21:00:22 +0100 4684861 http://www.medworm.com/index.php?rid=4684860&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21439556%26dopt%3DAbstract Authors: Perepelov AV, Liu B, Senchenkova SN, Guo D, Shevelev SD, Feng L, Shashkov AS, Wang L, Knirel YA The O-polysaccharides were released by mild acid hydrolysis from the lipopolysaccharides of Escherichia coli O51 and Salmonella enterica O57 and found to possess the same structure, which was established by sugar analysis and 1D and 2D NMR spectroscopy: The O-antigen gene clusters of E. coli O51 and S. enterica O57 were sequenced and found to contain the same genes with a high-level similarity. All genes expected for the synthesis of the O-antigen were identified based on their similarity to genes from available databases. PMID: 21439556 [PubMed - in process] (Source: Carbohydrate Research) Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4684860 Thu, 07 Apr 2011 21:00:17 +0100 4684860 http://www.medworm.com/index.php?rid=4684859&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21439557%26dopt%3DAbstract Authors: Karthik Kumar K, Mohan Das T A multicomponent one-pot reaction involving propargyl glycosides, methoxy-substituted aromatic aldehydes and aromatic amines using Cu(I) as catalyst is described, which provides an efficient and practical route to synthesize several quinoline-based glycoconjugates in good yield. PMID: 21439557 [PubMed - in process] (Source: Carbohydrate Research) Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4684859 Thu, 07 Apr 2011 21:00:12 +0100 4684859 http://www.medworm.com/index.php?rid=4684858&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21439558%26dopt%3DAbstract Authors: Vera C, Guerrero C, Illanes A The catalytic potential of β-galactosidase is usually determined by its hydrolytic activity over natural or synthetic substrates. However, this method poorly predicts enzyme behavior when transglycosylation instead of hydrolysis is being performed. A system for determining the transgalactosylation activity of β-galactosidase from Aspergillus oryzae was developed, and its activity was determined under conditions for the synthesis of galacto-oligosaccharides and lactulose. Transgalactosylation activity increased with temperature up to 55°C while the effect of pH was mild in the range from pH 2.5 to 5.5, decreasing at higher values. The effect of glucose and galactose on transgalactosylation activity was also assessed both in the reactions for the... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4684858 Thu, 07 Apr 2011 21:00:08 +0100 4684858 http://www.medworm.com/index.php?rid=4566402&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21345419%26dopt%3DAbstract Authors: Viana PA, de Rezende ST, Alves Ade A, Manfrini RM, Alves RJ, Bemquerer MP, Santoro MM, Guimarães VM α-d-Galactopyranosides were synthesized and their inhibitory activities toward the Debaryomyces hansenii UFV-1 extracellular and intracellular α-galactosidases were evaluated. Methyl α-d-galactopyranoside was the most potent inhibitor compared to the others tested, with K(i)(') values of 0.82 and 1.12mmolL(-1), for extracellular and intracellular enzymes, respectively. These results indicate that the presence of a hydroxyl group in the C-6 position of α-d-galactopyranoside derivatives is important for the recognition by D. hansenii UFV-1 α-galactosidases. PMID: 21345419 [PubMed - in process] (Source: Carbohydrate Research) Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4566402 Thu, 10 Mar 2011 06:45:49 +0100 4566402 http://www.medworm.com/index.php?rid=4566401&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21349499%26dopt%3DAbstract Authors: Shervani Z, Yamamoto Y A monosaccharide (β-d-glucose) and polysaccharide (soluble starch) were used as structure directing and subsequently stabilizing agents for the synthesis of spherical nanoparticles (NPs) and nanowires of silver and gold. Homogeneous monodispersed Ag(0) nanoparticles (Ag NPs) of 15nm diameter were obtained when 10(-4)M AgNO(3) precursor salt was reduced in starch (1wt%)-water gel by 1wt% β-d-glucose. For a second preparation the effect of reducing agents on the synthesis of Au(0) metallic nanoparticles (Au NPs) of 2×10(-4)M concentration prepared in a β-d-glucose (0.03M)-water dispersion was studied first in detail. Different equivalent amounts of NaBH(4) and a number of pH values were evaluated for the reduction of the Au salt HAuCl(4)·3H(2)O to obt... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4566401 Thu, 10 Mar 2011 06:45:45 +0100 4566401 http://www.medworm.com/index.php?rid=4566400&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21353204%26dopt%3DAbstract Authors: Bhatt LR, Kim BM, Hyun K, Kang KH, Lu C, Chai KY Acylation of chitin with butyric acid was performed in the presence of trifluoroacetic anhydride/phosphoric acid mediated system. The products were characterized by (1)H NMR and FT-IR spectroscopy and their solubility was tested in different organic solvents. Inclusion of butyric acid moieties into the parent molecule was confirmed from the (1)H NMR and FT-IR spectra. FT-IR analysis revealed that the degree of acid substitution (DS) of the products was in a range of 1.9-2.38, which increased with increasing the amounts of butyric acid added to the reaction system. Degree of N-deacetylation (DD) of the products, as determined by (1)H NMR was between 54.2% and 65.6%. The products with DS >2.0 were soluble in dimethyl sulfoxide,... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4566400 Thu, 10 Mar 2011 06:45:41 +0100 4566400 http://www.medworm.com/index.php?rid=4566399&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21353205%26dopt%3DAbstract Authors: Bera S, Zhanel GG, Schweizer F Amphiphilic lysine-ligated neomycin B building blocks were prepared by reductive amination of a protected C5″-modified neomycin B-based aldehyde and side chain-unprotected lysine or lysine-containing peptides. It was demonstrated that a suitably protected lysine-ligated neomycin B conjugate (NeoK) serves as a building block for peptide synthesis, enabling incorporation of aminoglycoside binding sites into peptides. Antibacterial testing of three amphiphilic lysine-ligated neomycin B conjugates against a representative panel of Gram-positive and Gram-negative strains demonstrates that C5″-modified neomycin-lysine conjugate retains antibacterial activity. However, in most cases the lysine-ligated neomycin B analogs display reduced potency again... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4566399 Thu, 10 Mar 2011 06:45:38 +0100 4566399 http://www.medworm.com/index.php?rid=4566398&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21353206%26dopt%3DAbstract Authors: He YW, Cao LH, Zhang JB, Wang DZ, Aisa HA A series of new N'-[N-(2,3,4-tri-O-acetyl-β-d-xylopyranosyl)thiocarbamoyl]-2-[(1-aryl-1H-tetrazol-5-yl)sulfanyl]acetohydrazides 5a-5e were synthesized rapidly in high yields from 2-(1-aryl-1H-tetrazol-5-ylsulfanyl)acetohydrazides 3a-3e and 2,3,4-tri-O-acetyl-β-d-xylopyranosyl isothiocyanate 4, then 5a-5e were converted to a series of new 5-(1-aryl-1H-tetrazol-5-ylsulfanylmethyl)-N-(2,3,4-tri-O-acetyl-β-d-xylopyranosyl)-1,3,4-oxadiazole-2-amines 6a-6e and 5-(1-aryl-1H-tetrazol-5-ylsulfanylmethyl)-N-(2,3,4-tri-O-acetyl-β-d-xylopyranosyl)-1,3,4-thiadiazole-2-amines 7a-7e, respectively under mercuric acetate/alcohol system or acetic anhydride/phosphoric acid system, then deacetylated in the solution of CH(3)ONa/CH(3)OH. All of the nove... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4566398 Thu, 10 Mar 2011 06:45:34 +0100 4566398 http://www.medworm.com/index.php?rid=4566397&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21353207%26dopt%3DAbstract Authors: Stevens JD Isolation of 1,2:3,4-di-O-isopropylidene-α-d-glucoseptanose and 2,3:4,5-di-O-isopropylidene-β-d-glucoseptanose from the mother-liquors from commercial scale preparation of 1,2:5,6-di-O-isopropylidene-α-d-glucofuranose is described. PMID: 21353207 [PubMed - in process] (Source: Carbohydrate Research) Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4566397 Thu, 10 Mar 2011 06:45:30 +0100 4566397 http://www.medworm.com/index.php?rid=4566396&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21353667%26dopt%3DAbstract Authors: Caratzoulas S, Vlachos DG We studied the energetics of the closed-ring mechanism of the acid-catalysed dehydration of d-fructose to 5-hydroxymethylfurfural (HMF) by carrying out canonical ensemble free-energy calculations using bias-sampling, hybrid Quantum Mechanics/Molecular Mechanics Molecular Dynamics simulations with explicit water solvent at 363K. The quantum mechanical calculations are performed at the PM3 theory level. We find that the reaction proceeds via intramolecular proton and hydride transfers. Solvent dynamics effects are analysed, and we show that the activation energy for the hydride transfers is due to re-organization of the polar solvent environment. We also find that in some instances intramolecular proton transfer is facilitated by mediating water, wherea... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4566396 Thu, 10 Mar 2011 06:45:26 +0100 4566396 http://www.medworm.com/index.php?rid=4566391&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21382612%26dopt%3DAbstract Authors: Qu J, Hu Q, Shen K, Zhang K, Li Y, Li H, Zhang Q, Wang J, Quan W Chitosan composite rods (CS-Fe(3+)) were prepared via an in situ precipitation method. The relationships among the preparation, structures, and properties of the CS-Fe(3+) composite rods have been investigated. The results of Fourier-transform infrared spectroscopy (FTIR) and core electron X-ray photoelectron spectroscopy (XPS) indicate that the CS and Fe(3+) are coordinated via a chelation mechanism. The content of Fe(3+) in the complex was determined by atomic absorption spectrometry (AAS) and elemental analysis (EA), the results of which suggested that the content of Fe(3+) in the complex can be controlled by the concentration of the ferric salts during coordination. The changes in thermal stability and crysta... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4566391 Sat, 05 Mar 2011 00:00:00 +0100 4566391 http://www.medworm.com/index.php?rid=4566393&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21377659%26dopt%3DAbstract Authors: Turska-Szewczuk A, Guz L, Lindner B, Pietras H, Russa R, Holst O The O-specific polysaccharide obtained by mild-acid degradation of lipopolysaccharide of Aeromonas bestiarum P1S was studied by sugar and methylation analyses along with (1)H and (13)C NMR spectroscopy. The sequence of the sugar residues was determined using (1)H,(1)H NOESY and (1)H,(13)C HMBC experiments. The O-specific polysaccharide was found to be a high-molecular-mass polysaccharide composed of tetrasaccharide repeating units of the structure Since small amounts of a terminal Quip3N residue were identified in methylation analysis, it was assumed that the elucidated structure also represented the biological repeating unit of the O-specific polysaccharide. PMID: 21377659 [PubMed - as supplied by publisher]... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4566393 Fri, 04 Mar 2011 00:00:00 +0100 4566393 http://www.medworm.com/index.php?rid=4566394&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21371691%26dopt%3DAbstract Authors: Vojtech M, Petrušová M, Valent I, Pribulová B, Petruš L Sodium methoxide-promoted methanolysis of 7-deoxy-7-nitro-l-glycero-l-galacto-heptitol peracetate rapidly and nearly quantitatively accumulates 7-deoxy-6-O-methyl-7-nitro-l-glycero-l-galacto-heptitol. The prolonged treatment then provides 76% of d-galactofuranosyl nitromethanes and finally results in the equilibrium of 77% of β-d-galactopyranosyl nitromethane and 7-9% of three other tautomeric d-galactosyl nitromethanes. Thermal treatment of 7-deoxy-7-nitro-l-glycero-l-galacto-heptitol in boiling water peaks at a 58% content of d-galactofuranosyl nitromethanes and ends in a similar equilibrium mixture of four d-galactosyl tautomers. The relevant kinetic parameters of the latter transformation are determined by a curv... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4566394 Tue, 01 Mar 2011 00:00:00 +0100 4566394 http://www.medworm.com/index.php?rid=4566395&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21367401%26dopt%3DAbstract Authors: Uccello-Barretta G, Evangelisti C, Balzano F, Vanni L, Aiello F, Jicsinszky L The complexation of heptakis(6-deoxy-6-thio)cyclomaltoheptaose to gold nanoparticles prepared by using the Metal Vapour Synthesis (MVS) led to water soluble gold nanoaggregates, thermally stable at 25°C. The role of gold concentration in the MVS-derived starting solution as well as of the cyclodextrin to gold molar ratio on the size of cyclodextrin-capped gold nanoparticles were investigated. The ability of cyclodextrin bonded to gold nanoparticles to include deoxycytidine was also probed in comparison with that of 1-thio-β-d-glucose sodium salt. PMID: 21367401 [PubMed - as supplied by publisher] (Source: Carbohydrate Research) Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4566395 Mon, 28 Feb 2011 00:00:00 +0100 4566395 http://www.medworm.com/index.php?rid=4566392&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21377660%26dopt%3DAbstract Authors: Abdelwahab NZ, Urbaniak MD, Ferguson MA, Crossman AT A small zinc-binding group (ZBG) library of deoxy-2-C-branched-monosaccharides, for example, 1,5-anhydroglucitols, consisting of either monodentate ligand binding carboxylic acids or bidentate ligand binding hydroxamic acids, were prepared to assess the zinc affinity of the putative metalloenzyme 2-acetamido-2-deoxy-α-d-glucopyranosyl-(1→6)-phosphatidylinositol de-N-acetylase (EC 3.5.1.89) of glycosylphosphatidylinositol biosynthesis. The N-ureido thioglucoside was also synthesised and added to the ZBG library because a previous N-ureido analogue, synthesised by us, had inhibitory activity against the aforementioned de-N-acetylase, presumably via the N-ureido motif. PMID: 21377660 [PubMed - as supplied by publisher] (... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4566392 Thu, 24 Feb 2011 00:00:00 +0100 4566392 http://www.medworm.com/index.php?rid=4454056&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21296220%26dopt%3DAbstract Authors: Gan Y, Zhang Y, Xiao C, Zhou C, Zhao Y A novel green synthesis process about methyl-β-cyclodextrin has been investigated through the reaction between β-cyclodextrin and dimethyl carbonate by anhydrous potassium carbonate as catalyst in DMF. The influence of experimental factors including the molar ratio of dimethyl carbonate to β-cyclodextrin, reaction temperature, and reaction time on the average degree of substitution of methyl-β-cyclodextrin was studied. The results show that the average degree of substitution of methyl-β-cyclodextrin can be dependent on the reaction temperature and the molar ratio of raw material primarily. The structures of methyl-β-cyclodextrin were characterized by TLC, IR, MS, (1)H NMR, and (13)C NMR. PMID: 21296220 [PubMed - in process] (Sou... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4454056 Wed, 09 Feb 2011 21:45:07 +0100 4454056 http://www.medworm.com/index.php?rid=4388478&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21193175%26dopt%3DAbstract Authors: Massen ZS, Sarli VC, Coutouli-Argyropoulou E, Gallos JK C-Glycoamino acids bearing a variety of sugar moieties were prepared by the hetero-Diels-Alder addition of ethyl 2-nitrosoacrylate to exo-glycals. The reaction proceeds smoothly to yield spirocyclic oxazines that can be converted into useful products by several hydrogenolytic techniques. PMID: 21193175 [PubMed - in process] (Source: Carbohydrate Research) Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4388478 Sun, 23 Jan 2011 23:16:32 +0100 4388478 http://www.medworm.com/index.php?rid=4388477&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21194682%26dopt%3DAbstract Authors: Prado HJ, Matulewicz MC, Bonelli PR, Cukierman AL Cationized agaroses with different degrees of substitution (0.04-0.77) were synthesized, employing 3-chloro-2-hydroxypropyltrimethylammonium chloride (CHPTAC). The influence of different reaction parameters on the substitution degree and molecular weight was evaluated. The investigated parameters were concentration of reagents, temperature, time, and addition of NaBH(4). The products were characterized by means of scanning electronic microscopy, infrared spectroscopy, viscosimetry, and NMR spectroscopy. Methanolysis products were studied by electrospray ionization mass spectrometry. The higher the concentration of CHPTAC employed, a higher degree of substitution was obtained, if the optimum concentration of NaOH in each case wa... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4388477 Sun, 23 Jan 2011 23:16:27 +0100 4388477 http://www.medworm.com/index.php?rid=4388470&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21237448%26dopt%3DAbstract Authors: Lavecchia MJ, Diez RP, Colinas PA The novel 4,6-di-O-acetyl-2,3-dideoxy-d-erythro-hex-2-enopyranosyl sulfamide, which exhibits selectivity for inhibiting isoform IX of carbonic anhydrase as overexpressed in many tumors, has been investigated from a combined theoretical and spectroscopic point of view. The conformational study of the compound shows that the α-anomeric form is more stable than the β-anomeric form from a thermodynamic point of view after including solvent effects. This fact suggests that the synthesis reaction could take place mainly under thermodynamic control as the main experimental product is the α-anomeric form of the sulfamide. Calculated α/β ratio is about 95:5, in excellent agreement with experimental data. Optimized geometries of the α-anomeric for... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4388470 Thu, 13 Jan 2011 00:00:00 +0100 4388470 http://www.medworm.com/index.php?rid=4388474&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21215963%26dopt%3DAbstract Authors: Dilokpimol A, Nakai H, Gotfredsen CH, Appeldoorn M, Baumann MJ, Nakai N, Schols HA, Hachem MA, Svensson B Two β-xylosidases of glycoside hydrolase family 3 (GH 3) from Aspergillus nidulans FGSC A4, BxlA and BxlB were produced recombinantly in Pichia pastoris and secreted to the culture supernatants in yields of 16 and 118mg/L, respectively. BxlA showed about sixfold higher catalytic efficiency (k(cat)/K(m)) than BxlB towards para-nitrophenyl β-d-xylopyranoside (pNPX) and β-1,4-xylo-oligosaccharides (degree of polymerisation 2-6). For both enzymes k(cat)/K(m) decreased with increasing β-1,4-xylo-oligosaccharide chain length. Using pNPX as donor with 9 monosaccharides, 7 disaccharides and two sugar alcohols as acceptors 18 different β-xylosyl-oligosaccharides were synthesis... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4388474 Fri, 17 Dec 2010 00:00:00 +0100 4388474 http://www.medworm.com/index.php?rid=4388472&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21232736%26dopt%3DAbstract Authors: Perepelov AV, Kocharova NA, Knirel YA, Jansson PE, Weintraub A The O-polysaccharide of Vibriocholerae O43 was studied using chemical analyses, triflic acid solvolysis and 2D NMR spectroscopy, including (1)H/(1)H COSY, TOCSY, NOESY and (1)H/(13)C gradient-selected HSQC experiments. The following structure of the tetrasaccharide repeating unit of the polysaccharide was established: →3)-β-d-Quip4NAcyl-(1→3)-α-d-GalpNAcA-(1→4)-α-d-GalpNAc-(1→3)-α-d-QuipNAc-(1→ where d-QuiNAc stands for 2-acetamido-2,6-dideoxy-d-glucose, d-Qui4NAcyl for 4-(N-acetyl-l-allothreonyl)amino-4,6-dideoxy-d-glucose and d-GalNAcA for 2-acetamido-2-deoxy-d-galacturonic acid. PMID: 21232736 [PubMed - as supplied by publisher] (Source: Carbohydrate Research) Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4388472 Fri, 17 Dec 2010 00:00:00 +0100 4388472 http://www.medworm.com/index.php?rid=4388471&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21236416%26dopt%3DAbstract Authors: Mitić Z, Cakić M, Nikolić GM, Nikolić R, Nikolić GS, Pavlović R, Santaniello E Bioactive copper(II) complexes with polysaccharides, like pullulan and dextran, are important in both veterinary and human medicine for the treatment of hypochromic microcitary anemia and hypocupremia. In aqueous alkaline solutions, Cu(II) ion forms complexes with the exopolysaccharide pullulan and its reduced low-molecular derivative. The metal content and the solution composition depend on pH, temperature, and time of the reaction. The complexing process begins in a weak alkali solution (pH >7) and involves OH groups of pullulan monomer (glucopyranose) units. Complexes of Cu(II) ion with reduced low-molecular pullulan (RLMP, M(w) 6000gmol(-1)) were synthesized in water solutions, at the b... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4388471 Fri, 17 Dec 2010 00:00:00 +0100 4388471 http://www.medworm.com/index.php?rid=4388473&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21232735%26dopt%3DAbstract Authors: Bajić A, Zakrzewska J, Godjevac D, Andjus P, Jones DR, Spasić M, Spasojević I The cytoprotective activity of F16BP has been documented in severe conditions such as convulsions, reperfusion injury, septic shock, diabetic complications, hypothermia-induced injury, UV-provoked skin damage and in other processes including apoptosis and excitotoxicity. F16BP shows very efficient cytoprotective activity in astroglial cells exposed to H(2)O(2)-provoked oxidative stress and during neuronal injury caused by hypoxic conditions. As most of the aforementioned processes involve iron activity-related conditions, we investigated the ferric and ferrous iron binding properties of F16BP under physiological conditions using (31)P NMR and EPR spectroscopy. Our results indicate that cytoprotect... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4388473 Tue, 14 Dec 2010 00:00:00 +0100 4388473 http://www.medworm.com/index.php?rid=4388475&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21215392%26dopt%3DAbstract Authors: Sarkar S, Sucheck SJ A hurdle in glycosylation reactions of 2-acetamido glycosyl donors is the formation of a stable and unreactive oxazoline that decreases the yield of these reactions significantly. As an effort to prevent oxazoline formation during glycosylation reactions, we protected the N-H of the acetamido group within a 2-acetamido-2-deoxy-1-thio-β-d-glucoside with one of four different protecting groups. These groups were either 2-methylenenapthyl, 4-methoxybenzyl, 3,4-dimethoxybenzyl or 2,4,6-trimethoxybenzyl. The resulting N-alkylacetamides were then used in glycosylation reactions with ethanol as a model acceptor. We observed that the ethyl glycosides obtained in each case were obtained with exclusive β-selectivity without the formation of oxazoline sideproducts.... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4388475 Sat, 11 Dec 2010 00:00:00 +0100 4388475 http://www.medworm.com/index.php?rid=4388476&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21215391%26dopt%3DAbstract Authors: Svensson MV, Weintraub A, Widmalm G The structure of the O-antigen polysaccharide (PS) from Escherichia coli O175 has been elucidated. Component analysis together with (1)H and (13)C NMR spectroscopy experiments were used to determine the structure. Inter-residue correlations were determined by (1)H,(1)H-NOESY, and (1)H,(13)C-heteronuclear multiple-bond correlation experiments. The PS is composed of pentasaccharide repeating units with the following structure: →2)-α-d-Glcp-(1→4)-α-d-GlcpA-(1→3)-α-d-Manp-(1→2)-α-d-Manp-(1→3)-β-d-GalpNAc-(1→ Cross-peaks of low intensity from an α-linked glucopyranosyl residue were present in the (1)H,(1)H-TOCSY NMR spectra. The α-d-Glcp residue is suggested to originate from the terminal part of the polysaccharide and conseque... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4388476 Fri, 10 Dec 2010 00:00:00 +0100 4388476 http://www.medworm.com/index.php?rid=4297687&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21146810%26dopt%3DAbstract Authors: Rougier NM, Cruickshank DL, Vico RV, Bourne SA, Caira MR, Buján EI, de Rossi RH The hydrolysis reaction of fenitrothion was studied in water containing 2% dioxane and in the presence of native cyclodextrins (α-, β- and γ-CD) and two commercially available modified derivatives, namely, permethylated β- and α-cyclodextrin (TRIMEB and TRIMEA, respectively). The kinetics of the reaction in the presence of TRIMEA could not be measured because the complex formed is insoluble and precipitated even at low concentration. On the other hand, the reaction is only weakly affected by the presence of α-CD. The hydrolysis reaction is inhibited by all the other cyclodextrins. From the kinetic data the association equilibrium constants for the formation of the 1:1 inclusion complexes wer... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4297687 Fri, 10 Dec 2010 00:00:00 +0100 4297687 http://www.medworm.com/index.php?rid=4297688&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21146156%26dopt%3DAbstract Authors: Khamwong C, Sakee U Both palladium(0) and palladium(II) methods for catalyzed hydroamination of C-(tetra-O-acetyl-β-d-galactopyranosyl)allene with a variety of aromatic amines have been successfully developed. PMID: 21146156 [PubMed - as supplied by publisher] (Source: Carbohydrate Research) Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4297688 Thu, 09 Dec 2010 00:00:00 +0100 4297688 http://www.medworm.com/index.php?rid=4297686&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21176892%26dopt%3DAbstract Authors: Bastide L, Priem B, Fort S This work reports the synthesis and the biological validation of a trisaccharide analogue of the HNK-1 epitope. The 3-O-sulfo-β-d-GlcpA-(1→3)-β-d-Galp-(1→4)-β-d-Glcp-allyl has been prepared by enzymatic glucuronylation of allyl lactoside by an engineered recombinant Escherichia coli strain followed by a chemoselective sulfation. Subsequent covalent attachment of the ozone-oxidised trisaccharide to bovine serum albumin provided a neo-glycoconjugate, which has been interrogated with antibodies specific to the human natural killer carbohydrate epitope HNK-1. ELISA assays confirmed the absolute requirement of the sulfate group for protein recognition and the potential application of this synthetic oligosaccharide as HNK-1 surrogate. PMID: 2117... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4297686 Fri, 03 Dec 2010 00:00:00 +0100 4297686 http://www.medworm.com/index.php?rid=4297685&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21185012%26dopt%3DAbstract Authors: Feng W, Fang Z, Yang J, Zheng B, Jiang Y Condensation between unprotected aldoses and dibenzoylmethane catalyzed by NaHCO(3) in the cosolvents EtOH and H(2)O (4:1) under microwave irradiation gave aryl ketone β-C-glycosides 6b-i in higher yields (from 50% with C-riboside 6g up to 99% with C-glucoside 6b) and better anomeric selectivities (β-configuration >95%) in a shorter reaction time (90min), compared with previous conventional methodologies. This method provides an attractive alternative to the existing means for the preparation of high value ketone β-C-glycosides. PMID: 21185012 [PubMed - as supplied by publisher] (Source: Carbohydrate Research) Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4297685 Fri, 03 Dec 2010 00:00:00 +0100 4297685 http://www.medworm.com/index.php?rid=4243268&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21130983%26dopt%3DAbstract Authors: Nassar MI, Mohamed TK, El-Toumy SA, Gaara AH, El-Kashak WA, Brouard I, El-Kousy SM Investigation of the aqueous alcoholic extract of Pyruscalleryana Decne. leaves led to the isolation of two new phenolic acids glycosides, namely protocatechuoylcalleryanin-3-O-β-glucopyranoside (1) and 3'-hydroxybenzyl-4-hydroxybenzoate-4'-O-β-glucopyranoside (2), together with nine known compounds among them lanceoloside A and methylgallate, which have been isolated for the first time from the genus Pyrus. Structures of the isolated compounds were established by spectroscopic analysis, including UV, IR, HRESI-MS, and 1D/2D NMR. The total extract and some isolated compounds were determined against DPPH (2,2-diphenyl-1-(2,4,6-trinitrophenyl) hydrazinyl radical, for their free radical scavengin... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4243268 Fri, 03 Dec 2010 00:00:00 +0100 4243268 http://www.medworm.com/index.php?rid=4211693&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21109235%26dopt%3DAbstract Authors: Wen JL, Xiao LP, Sun YC, Sun SN, Xu F, Sun RC, Zhang XL The physicochemical properties and structural characteristics of seven alkali-soluble hemicellulosic preparations were determined. These were extracted from bamboo (Bambusa rigida) with 1M NaOH, KOH, LiOH, NH(3)·H(2)O, (CH(3)CH(2))(3)N, Ca(OH)(2), Ba(OH)(2), respectively, at 50°C for 3h, were comparatively studied. Sugar analysis showed that these hemicelluloses contained d-xylose as the major constituent, along with d-glucose and l-arabinose in noticeable amounts. Uronic acids, principally 4-O-methyl-d-glucuronic acid, occurred in a small amount. Furthermore, based on the sugar analysis and FTIR and NMR spectroscopy, it can be concluded that the hemicelluloses consist of a backbone of β-(1→4)-linked d-xylopyranosyl ... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4211693 Tue, 23 Nov 2010 00:00:00 +0100 4211693 http://www.medworm.com/index.php?rid=4211700&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21093852%26dopt%3DAbstract Authors: Kwon C, Jung S α-Cyclosophoro-octadecaoses (α-C18), produced by Rhodobacter sphaeroides, are mostly homogeneous in size with 18 glucose units per ring as the predominant form. α-C18s are linked by β-(1→4)-linkages and one α-(1→6)-linkage and are also known to be highly substituted by acetyl (0-2 per mol) and/or succinoyl groups (1-7 per mol). We isolated and purified α-C18 and successfully used it in capillary electrophoresis (CE) as a chiral additive for the separation of five flavanones and flavanone-7-O-glycosides, including naringenin, hesperetin, eriodictyol, homoeriodictyol, isosakuranetin, and hesperidin. Throughout the CE experiment with unsubstituted α-C18 (uα-C18) obtained after alkaline treatment of the isolated α-C18, we found that successful chiral se... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4211700 Thu, 18 Nov 2010 00:00:00 +0100 4211700 http://www.medworm.com/index.php?rid=4211704&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21092941%26dopt%3DAbstract Authors: Miranda-Calderón JE, Medina-Torres L, Tinoco-Mendez M, Moreno-Esparza R, Ruiz-Ramirez L, Gracia-Mora J, Gracia-Mora I, Bernad-Bernad MJ Casiopeínas® are a new generation of anticancer drugs that have shown great in vitro and in vivo antineoplastic activities. Information about interaction drug-excipient, for developing a based-nanoparticle drug delivery system, has not been investigated yet. In order to elucidate if chitosan (CS) modifies the copper complex due to its interaction with Cu(2+) ion, different studies in aqueous media between CS and Casiopeina III-ia (Cas III-ia) were carried out. CS-Cas III-ia mixtures were characterized by viscosity curves, UV-vis, EPR, and in vivo activity against HeLa cell line. Rheological behavior showed a decrease of viscosity when the d... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4211704 Wed, 17 Nov 2010 00:00:00 +0100 4211704 http://www.medworm.com/index.php?rid=4163623&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21067711%26dopt%3DAbstract Authors: Ogata M, Kameshima Y, Hattori T, Michishita K, Suzuki T, Kawagishi H, Totani K, Hiratake J, Usui T Selective adsorption and separation of β-glucosidase, endo-acting endo-β-(1→4)-glucanase I (EG I), and exo-acting cellobiohydrolase I (CBH I) were achieved by affinity chromatography with β-lactosylamidine as ligand. A crude cellulase preparation from Hypocrea jecorina served as the source of enzyme. When crude cellulase was applied to the lactosylamidine-based affinity column, β-glucosidase appeared in the unbound fraction. By contrast, EG I and CBH I were retained on the column and then separated from each other by appropriately adjusting the elution conditions. The relative affinities of the enzymes, based on their column elution conditions, were strongly dependent on th... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4163623 Mon, 08 Nov 2010 00:00:00 +0100 4163623 http://www.medworm.com/index.php?rid=4163624&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21056410%26dopt%3DAbstract Authors: Fu Q, Liang T, Zhang X, Du Y, Guo Z, Liang X A general and efficient hydrophobic interaction liquid chromatography (HILIC) method has been developed for the separation of various kinds of carbohydrates, ranging from galactooligosaccharides, carrageenan oligosaccharides, sodium alginate, chitooligosaccharides to higher molecular weight fructooligosaccharides. Three types of oligosaccharides (acidic, basic, and neutral) were purified by semi-preparative HILIC. As a result, 18 oligosaccharides in high purity were obtained and their degrees of polymerization ranged from DP 2 to 7. Furthermore, oligosaccharides of plant origin were enriched and fractionated by solid-phase extraction (SPE) on a graphitized carbon cartridge. The oligosaccharide fractions that eluted from the cartridg... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4163624 Thu, 04 Nov 2010 00:00:00 +0100 4163624 http://www.medworm.com/index.php?rid=4163625&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21047623%26dopt%3DAbstract Authors: Jolie RP, Duvetter T, Van Loey AM, Hendrickx ME Pectin methylesterase (PME) catalyses the demethoxylation of pectin, a major plant cell wall polysaccharide. Through modification of the number and distribution of methyl-esters on the pectin backbone, PME affects the susceptibility of pectin towards subsequent (non-) enzymatic conversion reactions (e.g., pectin depolymerisation) and gel formation, and, hence, its functionality in both plant cell wall and pectin-containing food products. The enzyme plays a key role in vegetative and reproductive plant development in addition to plant-pathogen interactions. In addition, PME action can impact favourably or deleteriously on the structural quality of plant-derived food products. Consequently, PME and also the proteinaceous PME inhibi... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4163625 Mon, 01 Nov 2010 00:00:00 +0100 4163625 http://www.medworm.com/index.php?rid=4134574&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21035112%26dopt%3DAbstract Authors: Kanemaru M, Kuwahara SY, Yamamoto K, Kaneko Y, Kadokawa JI In this paper, we report the self-assembly of 6-O- and 6'-O-hexadecylsucroses mixture under aqueous conditions. The mixture was synthesized by a five-step sequence from sucrose. The SEM image of a sample prepared by drying a dispersion of the mixture in water showed nanoparticles with the diameter of ∼50nm and aggregates that were formed by further assembly of them. The XRD measurement of the sample exhibited the diffraction pattern assignable to face-centered cubic (FCC) structure and the diameter of a sphere, which took part in the FCC structure, was calculated to be 5.1nm. This value was relatively close to that observed in the DLS measurement of a dispersion of the mixture in water and estimated for a spherical m... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4134574 Wed, 27 Oct 2010 00:00:00 +0100 4134574 http://www.medworm.com/index.php?rid=4120922&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20974466%26dopt%3DAbstract Authors: Mallard I, Landy D, Bouchemal N, Fourmentin S A new fluorescent β-cyclodextrin has been synthesized by coupling an anthracene moiety to the cyclic oligosaccharide via click chemistry. The influence of the triazole spacer was compared to the simple amino and amido linkers. While a sensing ability toward adamantan-1-ol was observed with the latter two spacers, the absence of inclusion capacity prevents the triazole modified cyclodextrin from showing any fluorescence variations. The difference in the binding behaviors studied by Isothermal Titration Calorimetry, UV-vis and fluorescence spectroscopies, was highlighted by the NOESY NMR spectra of the modified cyclodextrins: whereas a free cavity was observed for the amino and amido linkers, an important obstruction was obtained in... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4120922 Sat, 23 Oct 2010 00:00:00 +0100 4120922 http://www.medworm.com/index.php?rid=4120921&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20974467%26dopt%3DAbstract Authors: Guillemineau M, Singh S, Grossutti M, Auzanneau FI We have synthesized four 6-thio pseudo glycolipid analogues and assessed how two of them self-assembled on a gold surface. These structures were designed as candidate tethers molecules to anchor bilayer lipid membranes on gold. 6-Deoxy-6-thiogalactose was chosen to anchor the macromolecule to the gold and define an aqueous zone at the gold surface. A long alkane chain (C-12 or C-18) linked to the anomeric position of the sugar residue was chosen to anchor a bilayer lipid membrane. The linkage between the carbohydrate and the hydrophobic chains is either a glycosidic bond or a 1,4-disubstituted triazole formed by copper(I)-catalysed alkyne-azide cycloaddition (CuAAC) of the propargyl glycoside with azido-dodecane and azido-octa... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4120921 Sat, 23 Oct 2010 00:00:00 +0100 4120921 http://www.medworm.com/index.php?rid=4106532&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20971448%26dopt%3DAbstract Authors: Dey B, Bhunia SK, Maity KK, Patra S, Mandal S, Maiti S, Maiti TK, Sikdar SR, Islam SS An immunoenhancing polysaccharide isolated from the aqueous extract of the fruit bodies of the mushroom, Pleurotus florida blue variant, was found to consist of d-glucose and d-galactose in a molar ratio of nearly 5:1. On the basis of sugar analysis, methylation analysis, periodate oxidation, Smith degradation, and NMR studies ((1)H, (13)C, DEPT-135, DQF-COSY, TOCSY, NOESY, ROESY, HMQC, and HMBC), the structure of the repeating unit of the polysaccharide was established as: The molecule activated macrophages, splenocytes, and thymocytes. PMID: 20971448 [PubMed - as supplied by publisher] (Source: Carbohydrate Research) Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4106532 Thu, 21 Oct 2010 23:00:00 +0100 4106532 http://www.medworm.com/index.php?rid=4106531&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20971455%26dopt%3DAbstract Authors: Ishikawa M, Koizumi S Previously, we described the production of N-acetylneuraminic acid (NeuAc) from N-acetylglucosamine (GlcNAc) in a system combining recombinant Escherichia coli expressing GlcNAc 2-epimerase (slr1975), E. coli expressing NeuAc synthetase (neuB), and Corynebacterium ammoniagenes. However, this system was unsuitable for large-scale production because of its complexity and low productivity. To overcome these problems, we constructed a recombinant E. coli simultaneously overexpressing slr1975 and neuB. This recombinant E. coli produced 81mM (25g/L) NeuAc in 22h without the addition of C. ammoniagenes cells. For manufacturing on an industrial scale, it is preferable to use unconcentrated culture broth as the source of enzymes, and therefore, a high-density cell... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4106531 Thu, 21 Oct 2010 23:00:00 +0100 4106531 http://www.medworm.com/index.php?rid=4057422&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20934686%26dopt%3DAbstract Authors: Amer A, Ayoup MS, Khattab SN, Hassan SY, Langer V, Senior S, Massry AM The synthesis of a new series of acyclic triazoloquinoxalinyl C-nucleosides and their transformation to their cyclic analogs are described following protection, activation, and deprotection with subsequent intramolecular nucleophilic substitution protocol. The antibacterial potency of the new compounds was determined using an inhibition zone diameter test. The results show that 3a and 2b exhibit good activity against Escherichiacoli and Candidaalbicans. On the other hand, the cyclic mesylated C-nucleoside 13 showed activity against the Gram-positive bacteria (Staphylococcusaureus) and antifungal activity against C. albicans. PMID: 20934686 [PubMed - as supplied by publisher] (Source: Carbohydrate Resear... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4057422 Thu, 07 Oct 2010 23:00:00 +0100 4057422 http://www.medworm.com/index.php?rid=4037488&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20883982%26dopt%3DAbstract Authors: Iynkkaran I, Bundle DR 2-Azido-4-benzylamino-4-N-,3-O-carbonyl-2,4,6-trideoxy-d-galactopyranosyl trichloroacetimidate (14) was conveniently prepared in six steps by regioselective introduction of an N-benzyl carbamate at O-3 of 6-deoxy-d-glucal 6, followed by mesylation at O-4. Intramolecular displacement of the leaving group afforded oxazolidinone 11. Azidonitration of the bicyclic glycal 11 gave the glycosyl nitrate anomers 12 in good yield and stereoselectivity. Hydrolysis of the anomeric nitrates under aqueous conditions gave the pyranose 13, which was easily converted into the imidate 14. Glycosylation of cyclohexanol by 14 gave glycosides 16α and 16β in a ratio of 4:1. PMID: 20883982 [PubMed - as supplied by publisher] (Source: Carbohydrate Research) Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4037488 Mon, 27 Sep 2010 23:00:00 +0100 4037488 http://www.medworm.com/index.php?rid=4024170&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20864092%26dopt%3DAbstract Authors: Braga HC, Wouters AD, Zerillo FB, Lüdtke DS The synthesis of seleno-galactopyranosides in a short and efficient manner is described, starting from the parent carbohydrate d-galactose. The approach described allows the synthesis of small libraries of compounds with a number of structural variations at the group attached to selenium. Compounds with aryl, propargyl, allyl, acyl, and alkyl substituents are described. PMID: 20864092 [PubMed - as supplied by publisher] (Source: Carbohydrate Research) Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=4024170 Mon, 20 Sep 2010 23:00:00 +0100 4024170 http://www.medworm.com/index.php?rid=3981183&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20846641%26dopt%3DAbstract Authors: Meloncelli PJ, Lowary TL The ABO histo-blood group system is one of the most clinically important antigen families. As part of our overall goal to prepare the entire set of the A, B and H type I-VI antigens for a range of biochemical investigations, we report herein the synthesis of the type I and II antigens with a 7-octen-1-yl aglycone. This linker was chosen to facilitate not only the future conjugation of the antigens to a protein or solid support but also the synthesis of the H type I and II octyl glycosides for enzyme kinetic studies. PMID: 20846641 [PubMed - as supplied by publisher] (Source: Carbohydrate Research) Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=3981183 Mon, 13 Sep 2010 23:00:00 +0100 3981183 http://www.medworm.com/index.php?rid=3960663&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20817140%26dopt%3DAbstract Authors: Sallam MA Treatment of 4-(d-manno-pentitol-1-yl)-2-phenyl-2H-1,2,3-triazole with one molar equivalent of 2,4,6-triisopropylbenzenesulfonyl chloride (TIBSCl) in pyridine solution afforded the homo-C-nucleoside analog; 4-(2,5-anhydro-d-manno-pentitol-1-yl)-2-phenyl-2H-1,2,3-triazole in 54% yield and 4-(alpha-d-arabinopyranosyl)-2-phenyl-2H1,2,3-triazole analog in 3% yield. The 4-(5-O-triisopropylbenzenesulfonyl)-d-manno-pentitol-1-yl)-2-phenyl-2H-1,2,3-triazole analog was isolated as an intermediate and identified as its tetra-O-acetyl derivative. The 4-(5-chloro-5-deoxy-d-manno-pentitol-1-yl)-2-phenyl-2H-1,2,3-triazole analog was isolated as a byproduct. The structure and anomeric configuration of the products were determined by acylation, NMR spectroscopy, and mass spectrometr... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=3960663 Wed, 01 Sep 2010 23:00:00 +0100 3960663 http://www.medworm.com/index.php?rid=3960664&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20813352%26dopt%3DAbstract Authors: Tamura JI, Nakamura-Yamamoto T, Nishimura Y, Mizumoto S, Takahashi J, Sugahara K Betaglycan, also known as TGF-beta type III receptor, is a membrane-anchored proteoglycan, which has two glycosaminoglycan (GAG) attachment sites (López-Casillas, F.; Payne, H. M.; Andres, J. L.; Massagué, J. J.Cell Biol.1994, 124, 557-568). Chondroitin sulfate (CS) or heparan sulfate (HS) can attach to the first site, Ser(535), whereas only CS attaches to the second, Ser(546). Although the mechanism behind the assembly of CS and HS is not fully understood, it has been reported that the assembly of HS requires not only a cluster of acidic residues but also hydrophobic residues located near the Ser-Gly attachment sites (Esko, J. D. Zhang, L. Curr. Opin. Struct. Biol.1996, 6, 663-670). To furt... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=3960664 Mon, 30 Aug 2010 23:00:00 +0100 3960664 http://www.medworm.com/index.php?rid=3960665&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20800223%26dopt%3DAbstract Authors: Ojha AK, Chandra K, Ghosh K, Islam SS Three different glucans (PS-I, PS-II, and PS-III) were isolated from the alkaline extract of the fruiting bodies of an edible mushroom Pleurotus florida, cultivar Assam Florida. On the basis of total acid hydrolysis, methylation analysis, periodate oxidation, Smith degradation, and NMR experiments ((1)H, (13)C, DEPT-135, DQF-COSY, TOCSY, NOESY, ROESY, HMQC, and HMBC), the structure of the repeating unit of these polysaccharides was established as follows: PMID: 20800223 [PubMed - as supplied by publisher] (Source: Carbohydrate Research) Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=3960665 Tue, 24 Aug 2010 23:00:00 +0100 3960665 http://www.medworm.com/index.php?rid=3908490&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20739019%26dopt%3DAbstract Authors: Kaur I, Kumar R, Sharma N Functionalization of rayon fibre has been carried out by grafting acrylic acid (AAC) both by a chemical method using a Ce(4+)-HNO(3) redox initiator and by a mutual irradiation (gamma-rays) method. The reaction conditions affecting the grafting percentage have been optimized for both methods, and the results are compared. The maximum percentage of grafting (50%) by the chemical method was obtained utilizing 18.24x10(-3)moles/L of ceric ammonium nitrate (CAN), 39.68x10(-2)moles/L of HNO(3), and 104.08x10(-2)moles/L of AAc in 20mL of water at 45 degrees C for120min. For the radiation method, the maximum grafting percentage (60%) was higher, and the product was obtained under milder reaction conditions using a lower concentration of AAc (69.38x10(-2)mole... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=3908490 Sun, 22 Aug 2010 23:00:00 +0100 3908490 http://www.medworm.com/index.php?rid=3908491&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20732678%26dopt%3DAbstract Authors: Westphal Y, Kühnel S, Schols HA, Voragen AG, Gruppen H Recently, various branched arabino-oligosaccharides as present in a sugar beet arabinan digest were characterized using NMR. Although HPAEC often has been the method of choice to monitor the enzymatic degradation reactions of polysaccharides, it was shown that HPAEC was incapable to separate all known linear and branched arabino-oligosaccharides present. As this lack of resolution might result in an incorrect interpretation of the results, other separation techniques were explored for the separation of linear and branched arabino-oligosaccharides. The use of porous-graphitized carbon liquid chromatography with evaporative light scattering and mass detection as well as capillary electrophoresis with laser-induced fluores... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=3908491 Fri, 20 Aug 2010 23:00:00 +0100 3908491 http://www.medworm.com/index.php?rid=3881262&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20709315%26dopt%3DAbstract Authors: Nunes SC, Jesus AJ, Moreno MJ, Eusébio ME This work presents an investigation on the conformational preferences of alpha,alpha-trehalose in gas phase and aqueous solution. Eighty-one systematically selected structures were studied at the B3LYP/6-311++G(d,p)//B3LYP/6-31G(d) level, giving rise to 40 unique conformers. The 19 lower energy structures and some selected other were further re-optimized at the B3LYP/6-311++G(d,p) level. The main factors accounting for the conformer's stability were pointed out and discussed. NBO and QTAIM analyses were performed in some selected conformers in order to address the anomeric and exo-anomeric effects as well as intramolecular hydrogen bonding. The effect of solvent water on the relative stability of the conformers was accounted for by ... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=3881262 Thu, 12 Aug 2010 23:00:00 +0100 3881262 http://www.medworm.com/index.php?rid=3849671&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20692650%26dopt%3DAbstract Authors: Falentin-Daudre C, Beaupère D, Stasik-Boutbaiba I d-Ribono-1,4-lactone was treated with ethylamine in DMF to afford N-ethyl-d-ribonamide 8a in quantitative yield. Using this reaction procedure, N-butyl, N-hexyl, N-dodecyl, N-benzyl, N-(3-methyl-pyridinyl)-, N-(2-hydroxy-ethyl)-, and N-(2-cyano-ethyl)-d-ribonamides 8b-h were obtained in quantitative yield. Bromination of the amides 8a-e with acetyl bromide in dioxane followed by acetylation gave 2,3,4-tri-O-acetyl-5-bromo-5-deoxy-N-ethyl, N-butyl, N-hexyl, N-dodecyl, and N-benzyl-d-ribonamides 9a-e in 40-54% yields. To obtain 2,3,4-tri-O-acetyl-5-bromo-5-deoxy-N-(3-methyl-pyridinyl)-, N-(2-hydroxy-ethyl)-, and N-(2-cyano-ethyl)-9f-h, the bromination is necessary before the amidation reaction. Treatment of the bromoamides 9a-... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=3849671 Thu, 05 Aug 2010 23:00:00 +0100 3849671 http://www.medworm.com/index.php?rid=3849672&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20691430%26dopt%3DAbstract Authors: Neoh TL, Koecher K, Reineccius G, Furuta T, Yoshii H The dissociation of a crystalline complex of cyclomaltohexaose (alpha-cyclodextrin) and 1-methylcyclopropene has been studied in response to stepwise rising relative humidity at 50 degrees C using a dynamic vapor sorption instrument. The dissociation of the inclusion complex was monitored with a proton transfer reaction mass spectrometer. The increase in relative humidity generally triggered the complex dissociation. However, the dissociation was greatly retarded at 80% relative humidity, presumably owing to collapse of the crystalline structure. Abrupt dissociation was observed at 90% relative humidity which corresponded to complex dissolution. The changes in powder X-ray diffraction pattern of the inclusion complex during ... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=3849672 Tue, 03 Aug 2010 23:00:00 +0100 3849672 http://www.medworm.com/index.php?rid=3817962&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20678757%26dopt%3DAbstract Conclusions concerning tautomerism of dye molecules were deduced from absorption spectra; the fractions of tautomers, tautomerization constants, and microscopic ionization constants were evaluated. These data allow concluding that the main reason for the aforementioned pK(a) alterations is the binding of H(2)R by the cyclodextrin cavity accompanied by turning these neutral species into the colorless lactone. The host-guest interaction of neutral species of fluorescein isothiocyanate, 2,7-dichlorofluorescein, and 3',4',5',6'-tetrachlorofluorescein also results in the cyclodextrin-assisted shift of tautomeric equilibrium. Such nature of interactions is proved by the addition of competing agents, camphor-4-carboxylic acid and sodium n-nonylsulfonate, which results in the removing of neutral d... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=3817962 Fri, 30 Jul 2010 23:00:00 +0100 3817962 http://www.medworm.com/index.php?rid=3817980&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20673658%26dopt%3DAbstract Authors: Li C, Zhao ZK, Wang A, Zheng M, Zhang T Acid-promoted, selective production of 5-hydroxymethylfurfural (HMF) under high fructose concentration conditions was achieved in ionic liquids (ILs) at 80 degrees C. A HMF yield up to 97% was obtained in 8min using 1-butyl-3-methylimidazolium chloride ([C(4)mim]Cl) catalyzed with 9mol% hydrochloric acid. More significantly, an HMF yield of 51% was observed when fructose was loaded at a high concentration of 67wt% in [C(4)mim]Cl. Water content below 15.4% in the system had little effect on HMF yield, whereas a higher water content was detrimental to both reaction rate and HMF yield. In situ NMR analysis suggested that the transformation of fructose to HMF was a highly selective reaction that proceeded through the cyclic fructofuranosyl i... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=3817980 Wed, 28 Jul 2010 23:00:00 +0100 3817980 http://www.medworm.com/index.php?rid=3817970&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20673882%26dopt%3DAbstract Authors: Jones RA, Davidson R, Tran AT, Smith N, Carmen Galan M An iodine-catalyzed one-pot tandem acetalation-esterification reaction of thio- and O-glycosides has been developed providing a fast and mild route to orthogonally protected glycosides ready to be used as building blocks in glycosylation reactions. PMID: 20673882 [PubMed - as supplied by publisher] (Source: Carbohydrate Research) Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=3817970 Wed, 28 Jul 2010 23:00:00 +0100 3817970 http://www.medworm.com/index.php?rid=3817982&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20673575%26dopt%3DAbstract Authors: Montaut S, Bleeker RS From the methanol extract of Cardamine diphylla rhizome, 5'-O-beta-d-glucopyranosyl-dihydroascorbigen (1) and 6-hydroxyindole-3-carboxylic acid 6-O-beta-d-glucopyranoside (2) were isolated. The structures of the compounds were elucidated using spectroscopic methods. This is the second report on the presence of a glucosylated indole ascorbigen in plants. PMID: 20673575 [PubMed - as supplied by publisher] (Source: Carbohydrate Research) Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=3817982 Mon, 26 Jul 2010 23:00:00 +0100 3817982 http://www.medworm.com/index.php?rid=3808880&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20667524%26dopt%3DAbstract Authors: Qian X, Johnson DK, Himmel ME, Nimlos MR Previously, theoretical multiple sugar (beta-d-xylose and beta-d-glucose) reaction pathways were discovered that depended on the initial protonation site on the sugar molecules using Car-Parrinello-based molecular dynamics (CPMD) simulations [Qian, X. H.; Nimlos, M. R.; Davis, M.; Johnson, D. K.; Himmel, M. E. Carbohydr. Res.2005, 340, 2319-2327]. In addition, simulation results showed that water molecules could participate in the sugar reactions, thus altering the reaction pathways. In the present study, the temperature and water density effects on the sugar degradation pathways were investigated with CPMD. We found that changes in both temperature and water density could profoundly affect the mechanisms and pathways. We attributed the... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=3808880 Sun, 25 Jul 2010 23:00:00 +0100 3808880 http://www.medworm.com/index.php?rid=3808879&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20667525%26dopt%3DAbstract Authors: Karki S, Yoo HG, Kwon SY, Suh JW, Kwon HJ Kitasatospora kifunensis, the talosin producer, was used as a source for the dTDP-6-deoxy-l-talose (dTDP-6dTal) biosynthetic gene cluster, serving as a template for four recombinant proteins of RmlA(Kkf), RmlB(Kkf), RmlC(Kkf), and Tal, which complete the biosynthesis of dTDP-6dTal from dTTP, alpha-d-glucose-1-phosphate, and NAD(P)H. The identity of dTDP-6dTal was validated using (1)H and (13)C NMR spectroscopy. K. kifunensistal and tll, the known dTDP-6dTal synthase gene of Actinobacillus actinomycetemcomitans origin, have low sequence similarity and are distantly related within the NDP-6-deoxy-4-ketohexose reductase family, providing an example of the genetic diversity within the dTDP-6dTal biosynthetic pathway. PMID: 20667525 [Pu... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=3808879 Sun, 25 Jul 2010 23:00:00 +0100 3808879 http://www.medworm.com/index.php?rid=3758356&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20620253%26dopt%3DAbstract Authors: Mukerjea R, Falconer DJ, Yoon SH, Robyt JF Soluble starch-synthesizing enzymes, starch synthase (SSS) and starch-branching enzyme (SBE), were isolated, fractionated, and purified from white potato tubers (Solanum tuberosum) on a large scale. Five steps were used: potato tuber extract from 2 kg of peeled potatoes, two acetone precipitations, and two fractionations on a large ultrafiltration polysulfone hollow fiber 100 kDa cartridge. Three kinds of fractions were obtained: (1) mixtures of SSS and SBE; (2) SSS, free of SBE; and (3) SBE, free of SSS. Contaminating enzymes (amylase, phosphorylase, and disproportionating enzyme) and carbohydrates were absent from the 2nd acetone precipitate and from the column fractions, as judged by the Molisch test and starch triiodide test. Acti... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=3758356 Fri, 16 Jul 2010 12:45:13 +0100 3758356 http://www.medworm.com/index.php?rid=3758355&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20620254%26dopt%3DAbstract Authors: Chen Q, Wu Y, Pu Y, Zheng Z, Shi C, Huang X Water-soluble 2'-O-hydroxypropyltrimethylammoniumchitin chloride (2'-O-HTACCt) was prepared directly from beta-chitin and 3-chloro-2-hydroxypropyltrimethylammonium chloride (CTA) in basic medium. The effect of alkali concentration, reaction temperature, reaction time, and dosage of CTA on yield and degree of substitution (DS) of 2'-O-HTACCt were studied. These quaternized chitin derivatives were characterized by FTIR and (1)H NMR spectroscopy, conductometric titration, and elemental analysis methods. Research results indicate that beta-chitin can react directly with CTA to produce a water-soluble 2'-O-HTACCt derivative with a high DS. The optimal preparation conditions were determined to be 35-40wt% (aq NaOH), 40 degrees C (reaction ... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=3758355 Fri, 16 Jul 2010 12:45:09 +0100 3758355 http://www.medworm.com/index.php?rid=3758357&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20620252%26dopt%3DAbstract Authors: Kosma P, Lowary T PMID: 20620252 [PubMed - in process] (Source: Carbohydrate Research) Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=3758357 Thu, 01 Jul 2010 23:00:00 +0100 3758357 http://www.medworm.com/index.php?rid=3758354&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20621289%26dopt%3DAbstract Authors: Silipo A, Gargiulo V, Sturiale L, Marchetti R, Prizeman P, Grant WD, Castro CD, Garozzo D, Lanzetta R, Parrilli M, Molinaro A The structure of the carbohydrate backbone of the core-lipid A region of the lipooligosaccharide (LOS) of the alkaliphilic and slightly halophilic bacterium Halomonas sp. has been elucidated. The LOS was fully deacylated, dephosphorylated, and reduced at the free reducing end. The structure, obtained by means of compositional analysis, 2D NMR spectroscopy, and MALDI mass spectrometry, was determined as the following: All sugars are d-pyranoses; Hep is l-glycero-d-manno-heptose and Kdo is 3-deoxy-d-manno-oct-2-ulosonic acid. PMID: 20621289 [PubMed - as supplied by publisher] (Source: Carbohydrate Research) Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=3758354 Mon, 21 Jun 2010 23:00:00 +0100 3758354 http://www.medworm.com/index.php?rid=3741248&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20615497%26dopt%3DAbstract Authors: Li Z Protecting groups often have profound influences on the stereoselectivity of glycosylation reactions. The effects of many protecting groups, especially cyclic protecting groups, are not well understood and difficult to explain and predict. Computational methods were used to study the effect of benzylidene acetal and cyclic carbonate protecting groups in glycosylation reactions, and the results provided a theoretical explanation for experimental observations. PMID: 20615497 [PubMed - as supplied by publisher] (Source: Carbohydrate Research) Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=3741248 Thu, 17 Jun 2010 23:00:00 +0100 3741248 http://www.medworm.com/index.php?rid=3741249&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20598293%26dopt%3DAbstract In this study, we prepared a polyelectrolyte complex (PEC) hydrogel comprising chitosan as the cationic polyelectrolyte and gamma-poly(glutamic acid) (gamma-PGA) as the anionic polyelectrolyte. Fourier transform infrared spectroscopy revealed that ionic complex interactions existed in the chitosan-gamma-PGA PEC hydrogels. The compressive modulus increased upon increasing the degree of complex formation in the chitosan-gamma-PGA PEC hydrogel; the water uptake decreased upon increasing the degree of complex formation. At the same degree of complex formation, the compressive modulus was larger for the chitosan-dominated PEC hydrogels; the water uptake was larger for the gamma-PGA-dominated ones. Scanning electron microscopy images revealed the existence of interconnected porous structures (po... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=3741249 Tue, 15 Jun 2010 23:00:00 +0100 3741249 http://www.medworm.com/index.php?rid=3688161&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20557875%26dopt%3DAbstract Authors: Kumar V A computational study on the glycoside hydrolase 13 (GH13) family of the CAZy database has been carried out at the atomic level in order to identify the conserved positions that may be responsible for recognition of the substrate. Analysis with substrate analog-, inhibitor-, or product-bound 3D structures was carried out to find the atomic spatial arrangement of the amino acids that make -2, -1, +1, and +2 subsites and water oxygen atoms around the ligand. The identified conserved positions of subsites were independent from the nature of the amino acid. The -1 and +1 subsites have more conserved positions than the -2 and +2 subsites. Some of the clusters of the -1 and +1 subsites have atoms of the same chemical nature. A spatially conserved position for water, which is... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=3688161 Mon, 14 Jun 2010 23:00:00 +0100 3688161 http://www.medworm.com/index.php?rid=3672303&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20538266%26dopt%3DAbstract Authors: Perepelov AV, Liu B, Senchenkova SN, Shashkov AS, Feng L, Knirel YA, Wang L An O-polysaccharide was obtained by mild acid degradation of the lipopolysaccharide of Salmonella enterica O60 strain G1462, and the following unique structure of the O-unit was determined by chemical analyses along with 2D (1)H and (13)C NMR spectroscopy: where Fuc3NFo stands for 3-formamido-3,6-dideoxygalactose. The structure established is in agreement with the O-antigen gene cluster of S. enterica O60, which contains putative genes for the synthesis of GDP-d-Man and dTDP-d-Fuc3NFo, three glycosyltransferase genes, and two O-unit-processing genes (wzx and wzy). PMID: 20538266 [PubMed - as supplied by publisher] (Source: Carbohydrate Research) Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=3672303 Sun, 30 May 2010 23:00:00 +0100 3672303 http://www.medworm.com/index.php?rid=3622625&cid=s_34405_50_f&fid=34405&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20513375%26dopt%3DAbstract Authors: Zarschler K, Janesch B, Kainz B, Ristl R, Messner P, Schäffer C The Gram-positive, mesophilic bacterium Paenibacillus alvei CCM 2051(T) possesses a two-dimensional crystalline protein surface layer (S-layer) with oblique lattice symmetry composed of a single type of O-glycoprotein species. Herein, we describe a strategy for nanopatterned in vivo cell surface co-display of peptide and glycan epitopes based on this S-layer glycoprotein self-assembly system. The open reading frame of the corresponding structural gene spaA codes for a protein of 983 amino acids, including a signal peptide of 24 amino acids. The mature S-layer protein has a theoretical molecular mass of 105.95kDa and a calculated pI of 5.83. It contains three S-layer homology domains at the N-terminus that are i... Carbohydrate Research journals http://www.medworm.com/rss/comments.php?id=3622625 Thu, 27 May 2010 23:00:00 +0100 3622625