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 'Bioinorganic Chemistry and Applications' source. Thu, 09 Feb 2012 13:38:28 +0100 http://www.medworm.com/index.php?rid=5673747&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fcrim%2Fotolaryngology%2F2012%2F262958%2F The posttraumatic cholesteatoma is a rare complication of different types of the temporal bone damage. Its diagnosis is often done after several years of evolution, sometimes even at the stage of complications. A case of posttraumatic cholesteatoma is presented that was revealed by a facial nerve paralysis 23 years after a crash of the external auditory canal underlining the importance of the otoscopic and radiological regular monitoring of the patients with a traumatism of the temporal bone. (Source: Bioinorganic Chemistry and Applications) Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=5673747 Thu, 09 Feb 2012 18:15:03 +0100 5673747 http://www.medworm.com/index.php?rid=4449629&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2010%2F603978.html The adsorption mechanism of the removal of lead from water by using carboxylic functional group (COOH) functionalized on the surface of carbon nanotubes was investigated. Four independent variables including pH, CNTs dosage, contact time, and agitation speed were carried out to determine the influence of these parameters on the adsorption capacity of the lead from water. The morphology of the synthesized multiwall carbon nanotubes (MWCNTs) was characterized by using field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) in order to measure the diameter and the length of the CNTs. The diameters of the carbon nanotubes were varied from 20 to 40 nm with average diameter at 24 nm and 10 micrometer in length. Results of the study showed that... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=4449629 Tue, 08 Feb 2011 23:24:48 +0100 4449629 http://www.medworm.com/index.php?rid=4300154&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2010%2F854514.html Four organotin(IV) complexes with 2-(2-hydroxybenzylideneamino)isoindoline-1,3-dione (L1), and 4-(4-hydroxy-3-methoxybenzylideneamino-N-(pyrimidin-2-yl)benzenesulfonamide (L2) were synthesized and well characterized by analytical and spectral studies. The synthesized compounds were tested for antimicrobial activity by disc diffusion method. The DNA binding of the complexes 1 and 3 with CT-DNA has been performed with absorption spectroscopy, which showed that both the complexes are avid binders of CT-DNA. Also the nuclease activity of complexes 1 and 3 with plasmid DNA (pUC19) was studied using agarose gel electrophoresis. The complex 1 can act as effective DNA cleaving agent when compared to complex 3 resulting in the nicked form of DNA under physiological conditions. The gel was run both ... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=4300154 Fri, 31 Dec 2010 07:38:15 +0100 4300154 http://www.medworm.com/index.php?rid=4284592&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2010%2F831031.html Pluripotent adipose tissue-derived stem cells (hASCs) can differentiate into various mesodermal cell types such as osteoblasts, chondroblasts, and myoblasts. We isolated hASCs from subcutaneous adipose tissue during orthopaedic surgery and induced the osteogenic differentiation for 28 days on three different synthetic scaffolds such as polylactide-co-glycolide (PLGA), polylactide-co-glycolide/hydroxyapatite (PLGA/HA), and trabecular titanium scaffolds (Ti6Al4V). Pore size can influence certain criteria such as cell attachment, infiltration, and vascularization. The aim of this study was to investigate the performance of PLGA and PLGA/HA scaffolds with a higher porosity, ranging between 75% and 84%, with respect to Ti scaffolds but with smaller pore size, seeded with hASCs to develop a mode... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=4284592 Fri, 24 Dec 2010 01:01:45 +0100 4284592 http://www.medworm.com/index.php?rid=4132299&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2010%2F651652.html The synthesis and characterization of two new tetronic acid zinc (II) complexes of the empirical formulae [Zn(L–H)2(H2O)2] (1) and [Zn(L–H)2(H2O)(MeOH)]H2O (2) found within the same crystal are reported. The zinc ions bind through alkoxide and carbonyl groups of the ligand 3-methoxycarbonyl-5-phenyl tetronic acid (LH) as indicated by H1 NMR and X-ray crystallographic studies. These complexes promote intra- and intermolecular interactions, such as hydrogen bonding and π stacking, giving place to the formation of molecular aggregates. (Source: Bioinorganic Chemistry and Applications) Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=4132299 Thu, 04 Nov 2010 18:48:19 +0100 4132299 http://www.medworm.com/index.php?rid=4104571&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2010%2F804854.html Biosorption experiment from aqueous solutions containing known amount of rare earth elements (REEs) using pre-treated Buccinum tenuissimum shell was explored to evaluate the efficiency of shell biomass as sorbent for REEs. In this work, four kinds of sieved shell samples: (a) “Ground original sample”, (b) “Heat-treatment (480∘C, 6 hours) sample”, (c) “Heat-treatment (950∘C, 6 hours) sample” and (d) “Heat-treatment (950∘C, 6 hours) and water added sample” were used. Furthermore, to confirm the characteristics of the shell biomass, the crystal structure, the surface morphology, and the specific surface area of these shell samples were determined. Consequently, the following matters have been mainly clarified... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=4104571 Tue, 26 Oct 2010 09:50:38 +0100 4104571 http://www.medworm.com/index.php?rid=3983138&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2010%2F364891.html In order to elucidate aspects of the mechanism of the hydrolytic enzyme urease, theoretical calculations were undertaken on a model of the active site, using density functional theory. The bridging oxygen donor that has been found in the crystal structures was determined to be a hydroxide ion. The initial coordination of urea at the active site occurs most likely through the urea oxygen to the nickel ion with the lowest coordination number. This coordination can be made without much gain in energy. The calculations also showed that weak coordination of one of the urea amine nitrogen atoms to the second nickel atom is energetically feasible. Furthermore, a proposed mechanism including a tetrahedral intermediate generated by hydrolytic attack on the urea carbon by the bridging hydroxide was ... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=3983138 Mon, 20 Sep 2010 09:59:15 +0100 3983138 http://www.medworm.com/index.php?rid=3935637&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2010%2F740435.html Interactions of nucleotides (AMP, CMP) and 1,2-diaminopropane (tn-1) or 2-methyl-1,2-diaminopropane (tn-2) in metal-free systems as well as in the systems including copper(II) ions were studied. The composition and overall stability constants of the complexes formed were determined by the potentiometric method, whereas the interaction centres and coordination sites were identified by spectroscopic methods. It was found that phosphate groups of nucleotides and the protonated amine groups of polyamines are the centres of interaction. The differences in the interactions with the polyamines which act as models of biogenic amines are impacted by the presence of lateral chains (methylene groups) in tn-1 and tn-2. In the ternary systems with Cu(II) ions, the heteroligand complexes are mainly of t... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=3935637 Mon, 06 Sep 2010 08:46:13 +0100 3935637 http://www.medworm.com/index.php?rid=3775730&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2010%2F178034.html Two new complexes, [Zn(O2CPh)2(L)2]·2MeOH  (1·2MeOH) and [Ni2(O2CPh))4(L)2]·2MeCN  (2·2MeCN), have been synthesized and characterized by X-ray analysis in the course of an ongoing investigation of the MII/X−/L  [MII=Co,Ni,Cu,Zn; X−=Cl−,Br−,I−,NCS−,NO3   −,N3   −,PhCO2   −; L=1-methyl-4,5-diphenylimidazole] reaction system, aiming at understanding and assessing the relative strength and the way in which the intermolecular interactions control the supramolecular organization of these compounds. In the mononuclear complex 1·2MeOH, the benzoate ion acts as a monodentate ligand resulting in a di... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=3775730 Thu, 22 Jul 2010 07:34:27 +0100 3775730 http://www.medworm.com/index.php?rid=3763973&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2010%2F159656.html The use of 2-pyridinealdoxime (paoH)/N,N′-donor ligand (L-L) “blend” in cobalt chemistry has afforded two cationic mononuclear cobalt(III) complexes of the general type [Co(pao)2(L-L)]+, where L-L = 1,10-phenanthroline (phen) and 2,2′-bipyridine (bpy). The CoCl2/paoH/L-L (1 : 2 : 1) reaction system in MeOH gives complexes [CoIII(pao)2(phen)]Cl⋅2H2O (1⋅2H2O) and [CoIII(pao)2(bpy)]Cl⋅1.5MeOH (2⋅1.5MeOH). The structures of the complexes were determined by single-crystal X-ray crystallography. The CoIII ions are six-coordinate, surrounded by three bidentate chelating ligands, that is, two pao- and one phen or bpy. The deprotonated oxygen atom of the pao- ligand remains uncoordinated and participates in hydr... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=3763973 Mon, 19 Jul 2010 07:27:14 +0100 3763973 http://www.medworm.com/index.php?rid=3763972&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2010%2F168030.html As part of our interest into the bioinorganic chemistry of gallium, gallium(III) complexes of the azole ligands 2,1,3-benzothiadiazole (btd), 1,2,3-benzotriazole (btaH), and 1-methyl-4,5-diphenylimidazole (L) have been isolated. Reaction of btaH or btd with GaBr3 or GaCl3 resulted in the mononuclear complexes [GaBr3(btaH)2] (1) and [GaCl3(btd)2] (2), respectively, while treatment of GaCl3 with L resulted in the anionic complex (LH)2[GaCl4] (3). All three complexes were characterized by single-crystal X-ray crystallography and IR spectroscopy, while their antiproliferative activities were investigated against a series of human and mouse cancer cell lines. (Source: Bioinorganic Chemistry and Applications) Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=3763972 Mon, 19 Jul 2010 07:27:14 +0100 3763972 http://www.medworm.com/index.php?rid=3763971&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2010%2F643120.html The catalytic decomposition of hydrogen peroxide by Cu(II) complexes with polymers bearing L-alanine (PAla) and glycylglycine (PGlygly) in their side chain was studied in alkaline aqueous media. The reactions were of pseudo-first order with respect to [H2O2] and [L-Cu(II)] (L stands for PAla or PGlygly) and the reaction rate was increased with pH increase. The energies of activation for the reactions were determined at pH 8.8, in a temperature range of 293–308 K. A suitable mechanism is proposed to account for the kinetic data, which involves the Cu(II)/Cu(I) redox pair, as has been demonstrated by ESR spectroscopy. The trend in catalytic efficiency is in the order PGlygly>PAla, due to differences in modes of complexation and in the conformation of the macromolecular l... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=3763971 Mon, 19 Jul 2010 07:27:14 +0100 3763971 http://www.medworm.com/index.php?rid=3743395&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2010%2F832768.html The reactions of 2,4- and 2,5-dihydroxybenzoic acids (dihydroxybenzoic acid, DHBA) with chromium(III) in weak acidic aqueous solutions have been shown to take place in at least two stages. The first stage of the reactions has an observed rate constant k1(obs)=k1[DHBA]+C and the corresponding activation parameters are ΔH1(2,4)≠=49,5 kJ/mol−1, ΔS1(2,4)≠=−103,7 J mol−1 K−1, ΔH1(2,5)≠=60,3 kJ/mol−1, and ΔS1(2,5)≠=−68,0 J mol−1 K−1. These are composite activation parameters and the breaking of the strong intramolecular hydrogen bonding in the two ligands is suggested to be the first step of the (composite) first stage of the reactions. The second stage is... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=3743395 Mon, 12 Jul 2010 07:21:56 +0100 3743395 http://www.medworm.com/index.php?rid=3724319&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2010%2F960571.html The reactions of methyl(2-pyridyl)ketone oxime, (py)C(Me)NOH, with manganese(II) sulfate monohydrate have been investigated. The reaction between equimolar quantities of MnSO4⋅H2O and (py)C(Me)NOH in H2O lead to the dinuclear complex [Mn2(SO4)2{(py)C(Me)NOH}4]⋅(py)C(Me)NOH, 1⋅(py)C(Me)NOH, while employment of NaOMe as base affords the compound [Mn(HCO2)2{(py)C(Me)NOH}2] (2). The structures of both compounds have been determined by single crystal X-ray diffraction. In both complexes, the organic ligand chelates through its nitrogen atoms. The IR data are discussed in terms of the nature of bonding and the structures of the two complexes. (Source: Bioinorganic Chemistry and Applications) Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=3724319 Mon, 05 Jul 2010 07:20:49 +0100 3724319 http://www.medworm.com/index.php?rid=3717857&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2010%2F149149.html New complexes of dioxovanadium(V), zinc(II), ruthenium(II), palladium(II), and platinum(II) with 6-methylpyridine-2-carbaldehyde-N(4)-ethylthiosemicarbazone (HmpETSC) have been synthesized. The composition of these complexes is discussed on the basis of elemental analyses, IR, Raman, NMR (H1, C13, and P31), and electronic spectral data. The X-ray crystal structures of [VO2(mpETSC)] and [Pt(mpETSC)Cl] are also reported. The HmpETSC and its [Zn(HmpETSC)Cl2] and [Pd(mpETSC)Cl] complexes exhibit antineoplastic activity against colon cancer human cell lines (HCT 116). (Source: Bioinorganic Chemistry and Applications) Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=3717857 Fri, 02 Jul 2010 07:23:40 +0100 3717857 http://www.medworm.com/index.php?rid=3713466&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2010%2F619436.html We report here a biophysical and biochemical approach to determine the differences in interactions of NiCR and NiCR-2H with DNA. Our goal is to determine whether such interactions are responsible for the recently observed differences in their cytotoxicity toward MCF-7 cancer cells. Viscosity measurement and fluorescence displacement titration indicated that both NiCR and NiCR-2H bind weakly to duplex DNA in the grooves. The coordination of NiCR-2H with the N-7 of 2′-deoxyguanosine 5′-monophosphate (5′-dGMP) is stronger than that of NiCR as determined by H1 NMR. NiCR-2H, like NiCR, can selectively oxidize guanines present in distinctive DNA structures (e.g., bulges), and notably, NiCR-2H oxidizes guanines more efficiently than NiCR. In addition, UV and H1 NMR studies re... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=3713466 Thu, 01 Jul 2010 07:22:27 +0100 3713466 http://www.medworm.com/index.php?rid=3713465&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2010%2F196064.html Conjugates of purine and pyrimidine nucleosides: thymidine and 2′-deoxyguanosine with cobalt-metallacarborane were studied for their sodium ion complexing properties. Formation of stable complexes of 1 : 1 stoichiometry was proved by ESI MS spectroscopy and 23Na NMR. Equilibrium constants and energies of complex formation were calculated. Complexation of alkali-metals by nucleoside-metallacarborane conjugates may affect the physicochemical and biological properties of the conjugates and should be taken into consideration during biological evaluation of these types of modifications. (Source: Bioinorganic Chemistry and Applications) Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=3713465 Thu, 01 Jul 2010 07:22:27 +0100 3713465 http://www.medworm.com/index.php?rid=3705957&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2010%2F731202.html Metal complexes bearing dichalcogenated imidodiphosphinate [R2P(E)NP(E)R2′]- ligands (E = O, S, Se, Te), which act as (E,E) chelates, exhibit a remarkable variety of three-dimensional structures. A series of such complexes, namely, square-planar [Cu{(OPPh2)(OPPh2)N-O,O}2], tetrahedral [Zn{(EPPh2)(EPPh2)N-E,E}2], E = O, S, and octahedral [Ga{(OPPh2)(OPPh2)N-O,O}3], were tested as potential inhibitors of either the platelet activating factor (PAF)- or thrombin-induced aggregation in both washed rabbit platelets and rabbit platelet rich plasma. For comparison, square-planar [Ni{(Ph2P)2N-S-CHMePh-P,P}X2], X = Cl, Br, the corresponding metal salts of all complexes and the (OPPh2)(OPPh2)NH ligand were also investigated. Ga(O,O)3 showed the highest anti-PAF activity but did ... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=3705957 Tue, 29 Jun 2010 07:27:48 +0100 3705957 http://www.medworm.com/index.php?rid=3705956&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2010%2F252348.html A series of 7 new human/rat Corticotropin Releasing Hormone (h/r-CRH) analogues were synthesized. The induced alterations include substitution of Phe at position 12 with D-Phe, Leu at positions 14 and 15 with Aib and Met at positions 21 and 38 with Cys(Et) and Cys(Pr). The analogues were tested regarding their binding affinity to the CRH-1 receptor and their activity which is represented by means of percentage of maximum response in comparison to the native molecule. The results indicated that the introduction of Aib, or Cys derivatives although altering the secondary structure of the molecule, did not hinder receptor recognition and binding. (Source: Bioinorganic Chemistry and Applications) Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=3705956 Tue, 29 Jun 2010 07:27:48 +0100 3705956 http://www.medworm.com/index.php?rid=3702758&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2010%2F323152.html Human Arkadia is a nuclear protein consisted of 989 amino acid residues, with a characteristic RING domain in its C-terminus. The RING domain harbours the E3 ubiquitin ligase activity needed by Arkadia to ubiquitinate its substrates such as negative regulators of TGF-β signaling. The RING finger domain of Arkadia is a RING-H2 type and its structure and stability is strongly dependent on the presence of two bound Zn(II) ions attached to the protein frame through a defined Cys3-His2-Cys3 motif. In the present paper we transform the RING-H2 type of Arkadia finger domain to nonnative RING sequence, substituting the zinc-binding residues Cys955 or His960 to Arginine, through site-directed mutagenesis. The recombinant expression, in Escherichia coli, of the mutants C955R and H960R reveal ... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=3702758 Mon, 28 Jun 2010 07:19:47 +0100 3702758 http://www.medworm.com/index.php?rid=3702757&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2010%2F618202.html N,N'-diethylurea (DEU) was employed as a ligand to form the octahedral complexes [M(DEU)6]2+ (M=Co, Ni and Zn). Compounds [Co(DEU)6](BF4)2 (1), [Co(DEU)6](CIO4)2 (2), [Ni(DEU)6](CIO4)2 (3), and [Zn(DMU)6](CIO4)2 (4) have been prepared from the reactions of DEU and the appropriate hydrated metal(II) salts in EtOH in the presence of 2,2-dimethoxypropane. Crystal structure determinations demonstrate the existence of [M(DEU)6]2+ cations and CIO4- (in 2–4) or BF4- (in 1) counterions. The [M(DEU)6]2+ cations in the solid state are stabilized by a pseudochelate effect due to the existence of six strong intracationic N-H⋯O(DEU) hydrogen bonds. The [M(DEU)6]2+ cations and counterions self-assemble to form hydrogen-bonded 2D architectures in 2–4 that conform to the kgd (kagom... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=3702757 Mon, 28 Jun 2010 07:19:47 +0100 3702757 http://www.medworm.com/index.php?rid=3694721&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2010%2F976901.html A series of metal-containing epoxy polymers have been synthesized by the condensation of epichlorohydrin (1-chloro-2,3-epoxy propane) with Schiff base metal complexes in alkaline medium. Schiff base was initially prepared by the reaction of 2,6 dihydroxy 1-napthaldehyde and o-phenylenediamine in 1  :  2 molar ratio and then with metal acetate. All the synthesized compounds were characterized by elemental, spectral, and thermal analysis. The physicochemical properties, viz., epoxy value, hydroxyl content, and chlorine content [mol/100 g] were measured by standard procedures. The antimicrobial activities of these metal-containing epoxy polymers were carried out by using minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC)... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=3694721 Fri, 25 Jun 2010 07:23:37 +0100 3694721 http://www.medworm.com/index.php?rid=3694720&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2010%2F861892.html A detailed catalytic study of LFeIIICl (where L=3-{2-[2-(3-hydroxy-1,3-diphenyl-allylideneamino)-ethylamino]-ethylimino}-1,3-diphenyl-propen-1-ol) for hydrocarbon oxidation was carried out, focusing on the role of solvent, atmospheric dioxygen, and oxidant on catalytic efficiency. The data showed that LFeIIICl catalyst was efficient in homogeneous hydrocarbon oxidations providing significant yields. Moreover, tert-BuOOH provided comparable oxidation yields with H2O2, slightly favoring the formation of alcohols and ketones versus epoxides. Dioxygen intervened in the catalytic reaction, influencing the nature of oxidation products. The polarity of solvent strongly influenced the reaction rates and the nature of oxidation products. A mechanistic model is postulated assuming that LFeIIICl func... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=3694720 Fri, 25 Jun 2010 07:23:37 +0100 3694720 http://www.medworm.com/index.php?rid=3690297&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2010%2F914580.html The 1 : 2 reaction of [Ti(η5-C5H5)2Cl2] and AgF in CHCl3/H2O yielded the fluoro analog [Ti(η5-C5H5)2F2] (1) in almost quantitative yield (C5H5 is the cyclopentadienyl group). The coordination about the TiIV atom formed by two fluoro ligands and the centroids of the cyclopentadienyl rings is distorted tetrahedral. The compound crystallizes in the orthorhombic space group C2cm. The lattice constants are a=5.9055(4),b=10.3021(5),c=14.2619(9) Å, and α=β=γ=90°. The complex has been characterized by elemental analyses and spectroscopic (IR, H1 NMR) data. A structural comparison of the four members of the [Ti(η5-C5H5)2X2] family of complexes (X=F,Cl,Br,I) is attempted. (Source: Bioinorganic Chemistry and Applications) Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=3690297 Thu, 24 Jun 2010 07:22:31 +0100 3690297 http://www.medworm.com/index.php?rid=3686520&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2010%2F634597.html The cytochrome c nitrite reductase (ccNiR) from Desulfovibrio desulfuricans ATCC 27774 is able to reduce nitrite to ammonia in a six-electron transfer reaction. Although extensively characterized from the spectroscopic and structural points-of-view, some of its kinetic aspects are still under explored. In this work the kinetic behaviour of ccNiR has been evaluated in a systematic manner using two different spectrophotometric assays carried out in the presence of different redox mediators and a direct electrochemical approach. Solution assays have proved that the specific activity of ccNiR decreases with the reduction potential of the electronic carriers and ammonium is always the main product of nitrite reduction. The catalytic parameters were discussed on the basis of the mediator reducin... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=3686520 Wed, 23 Jun 2010 07:15:37 +0100 3686520 http://www.medworm.com/index.php?rid=3686519&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2010%2F613140.html The novel lanthanide(III) complexes [Ln(NO3)2L](NO3)⋅3MeOH (Ln = La 1, Pr 2) and [Ln(NO3)3L](NO3)⋅2MeOH (Ln = Gd 3, Yb 4), where L = (NE,N′E)-2,2′-(ethane-1,2-diylbis(oxy))bis(N-(pyridin-2-ylmethylene)ethanamine), have been obtained by direct reaction of the Schiff base ligand and the corresponding hydrated lanthanide(III) nitrates in methanol. All complexes were characterized spectroscopically and thermogravimetrically. Complex 4 was also characterized with crystallographic studies: orthorhombic P212121, a=10.6683(14), b=13.4752(15), c=19.3320(26) Å. In the molecular structure of 4, Yb(III) is surrounded by all donor atoms of the Schiff base (four nitrogen and two oxygen atoms) and four oxygen atoms belonging to two bidentate chelating nitrato ligands. (... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=3686519 Wed, 23 Jun 2010 07:15:37 +0100 3686519 http://www.medworm.com/index.php?rid=3679627&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2010%2F867195.html The synthesis and spectral characterization of novel diorganotin complexes with 3-hydroxypyridine-2-carbaldehyde thiosemicarbazone, H2L(1), [SnMe2(L)] (2), [SnBu2(L)] (3), and [SnPh2(L)] (4) are reported. The single-crystal X-ray structure of complex [SnPh2(L)(DMSO)] (5) shows that the ligand is doubly deprotonated and is coordinated as tridentate ligand. The six coordination number is completed by two carbon atoms of phenyl groups. There are two similar monomers 5a (Sn1) and 5b (Sn51) in the asymmetric unit. The monomers 5a and 5b are linked through intermolecular hydrogen bonds of N–H–O and C–H–S type. C–H→π, intermolecular interactions, intra- and intermolecular hydrogen bonds stabilize this structure and leads to aggregation and a supramo... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=3679627 Mon, 21 Jun 2010 07:08:31 +0100 3679627 http://www.medworm.com/index.php?rid=3679626&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2010%2F936834.html Four cationic ruthenium(II) complexes with the formula [Ru(η5-C5H5)(PPh3)2]+, with L=5-phenyl-1H-tetrazole (TzH) 1, imidazole (ImH) 2, benzo[1,2-b;4,3-b′] dithio-phen-2-carbonitrile (Bzt) 3, and [5-(2-thiophen-2-yl)-vinyl]-thiophene-2-carbonitrile] (Tvt) 4 were prepared and characterized in view to evaluate their potentialities as antitumor agents. Studies by Circular Dichroism indicated changes in the secondary structure of ct-DNA. Changes in the tertiary structure of pBR322 plasmid DNA were also observed in gel electrophoresis experiment and the images obtained by atomic force microscopy (AFM) suggest strong interaction with pBR322 plasmid DNA; the observed decreasing of the viscosity with time indicates that the complexes do not intercalate between DNA base pairs. Compound... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=3679626 Mon, 21 Jun 2010 07:08:31 +0100 3679626 http://www.medworm.com/index.php?rid=3665401&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2010%2F292760.html The purpose of present study was to stabilize curcumin food pigment by its complexation with divalent ions like (Zn2+,Cu2+,Mg2+,Se2+), in “green media” and evaluate its stability in vitro compared to curcumin alone. The curcumin complexes were prepared by mechanical mixture of curcumin and sulfate salts of each metal (metal : curcumin 1/1mol) into unconventional and nontoxic glycerol/water solvent. Two stoichiometry of complex were obtained, 1 : 1 and 1 : 2 (metal/curcumin), respectively. On evaluation of in vitro stability, all complexes were found to provide a higher stability from curcumin alone. (Source: Bioinorganic Chemistry and Applications) Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=3665401 Wed, 16 Jun 2010 14:56:03 +0100 3665401 http://www.medworm.com/index.php?rid=3662057&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2010%2F104329.html The reaction of CoCl2·6H2O with m-BDTH2 (1,3-benzeneditetrazol-5-yl) leads to [Co(C8H6N8)2(H2O)2(CH3CN)2]Cl2 (1). Both tetrazolic groups remain protonated existing in a 1H tautomeric form. A trifurcated chlorine atom and stacking interactions assemble compound 1 into a three-dimensional network. (Source: Bioinorganic Chemistry and Applications) Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=3662057 Tue, 15 Jun 2010 15:01:40 +0100 3662057 http://www.medworm.com/index.php?rid=3647843&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2010%2F307696.html The synthesis of new trans A2B2-substituted porphyrins bearing oxygenic substituent (methoxy, acetoxy, hydroxy) at the periphery of the ring are described. All of the synthesized products were characterized by 1H-N.M.R., 13C-N.M.R., and H.R.M.S. Electrochemical studies revealed two one-electron oxidations and two reductions. In addition, the X-ray structure of one methoxy-derivative was determined. (Source: Bioinorganic Chemistry and Applications) Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=3647843 Thu, 10 Jun 2010 15:09:17 +0100 3647843 http://www.medworm.com/index.php?rid=3644156&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2010%2F165482.html The antioxidative activity of ferrocenes bearing either 2,6-di-tert-butylphenol or phenyl groups has been compared using DPPH (1,1-diphenyl-2-picrylhydrazyl) test and in the study of the in vitro impact on lipid peroxidation in rat brain homogenate and on some characteristics of rat liver mitochondria. The results of DPPH test at 20∘C show that the activity depends strongly upon the presence of phenolic group but is improved by the influence of ferrocenyl fragment. The activity of N-(3,5-di-tert-butyl-4-hydroxyphenyl)iminomethylferrocene (1), for instance, was 88.4%, which was higher than the activity of a known antioxidant 2,6-di-tert-butyl-4-methylphenol (BHT) (48.5%), whereas the activity of N-phenyl-iminomethylferrocene 2 was almost negligible −2.9%. The data ... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=3644156 Wed, 09 Jun 2010 15:00:22 +0100 3644156 http://www.medworm.com/index.php?rid=3644155&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2010%2F820476.html The rational design of synthetic peptides is proposed as an efficient strategy for the structural investigation of crucial protein domains difficult to be produced. Only after half a century since the function of ACE was first reported, was its crystal structure solved. The main obstacle to be overcome for the determination of the high resolution structure was the crystallization of the highly hydrophobic transmembrane domain. Following our previous work, synthetic peptides and Zinc(II) metal ions are used to build structural maquettes of the two Zn-catalytic active sites of the ACE somatic isoform. Structural investigations of the synthetic peptides, representing the two different somatic isoform active sites, through circular dichroism and NMR experiments are reported. (Source: Bioinorga... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=3644155 Wed, 09 Jun 2010 15:00:22 +0100 3644155 http://www.medworm.com/index.php?rid=3640118&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2010%2F125717.html In this study the speciation of the Cu2+ with iminodiacetic phenolate/hydroquinonate ligands has been examined by pH-potentiometry. The results reveal that the iminodiacetic phenol ligand forms mononuclear complexes with Cu2+ at acidic and alkaline pHs, and a binuclear Ophenolate-bridged complex at pH range from 7 to 8.5. The binucleating hydroquinone ligand forms only 2 : 1 metal to ligand complexes in solution. The pK values of the protonation of the phenolate oxygen of the two ligands are reduced about 2 units after complexation with the metal ion and are close to the pK values for the copper-interacting tyrosine phenol oxygen in copper enzymes. (Source: Bioinorganic Chemistry and Applications) Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=3640118 Tue, 08 Jun 2010 15:01:10 +0100 3640118 http://www.medworm.com/index.php?rid=3640117&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2010%2F973742.html The complex [ReOCl3pq] (1) (where pq = 2-(2′pyridyl)quinoxaline) has been synthesized and fully characterized by UV-Vis, FTIR, 1 and 2D NMR, and cyclic voltammetry (CV). The DNA-binding properties of the complex 1 as well as of the compounds [ReOCl3bpy] (2), [ReOCl3phen] (3), and pq (4) were investigated by UV-spectrophotometric (melting curves), CV (cyclic voltammetry), and viscosity measurements. Experimental data suggest that complex 1 intercalates into the DNA base pairs. Upon irradiation, complex 1 was found to promote the cleavage of plasmid pBR 322 DNA from supercoiled form I to nicked form II. The mechanism of the DNA cleavage by complex 1 was also investigated. (Source: Bioinorganic Chemistry and Applications) Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=3640117 Tue, 08 Jun 2010 15:01:10 +0100 3640117 http://www.medworm.com/index.php?rid=3640116&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2010%2F102863.html The synthesis, NMR characterization, and X-ray crystallography of “lantern-shaped” platinum(III) complexes with four pivaloamidate bridging ligands and two 9-ethylguanines (9-EtG) or 1-methylcytosines (1-MeC) in axial positions are reported: cis-N2O2-[Pt2{HN=C(But)O}4(9-EtG)2](NO3)2 and cis-N2O2-[Pt2{HN=C(But)O}4(1-MeC)2](NO3)2. The last complex is, to the best of our knowledge, the first dinuclear compound of platinum(III) with axially bound 1-MeC. (Source: Bioinorganic Chemistry and Applications) Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=3640116 Tue, 08 Jun 2010 15:01:10 +0100 3640116 http://www.medworm.com/index.php?rid=3635246&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2010%2F367128.html A new 1-D coordination polymer {[Mn6O2(O2CMe)10(H2O)4]⋅2.5H2O}∞ (1⋅2.5H2O)∞ and the cluster [Mn6O2(O2(O2CPh)10 (py)2(MeCN)(H2O)]⋅2MeCN (2⋅2MeCN) are reported. Both compounds were synthesized by room temperature reactions of [Mn3(μ3-O)(O2CR)6(L)2(L′)] (R = Me, L = L′ = py, (1⋅2.5H2O)∞; R = Ph, L = py, L′ = H2O, 2⋅2MeCN) in the presence of 3-hydroxymethylpyridine (3hmpH) in acetonitrile. The structures of these complexes are based on hexanuclear mixed-valent manganese carboxylate clusters containing the [Mn4IIMn2III(μ4-O)2]10+ structural core. (1⋅2.5H2O)∞ consists of zigz... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=3635246 Mon, 07 Jun 2010 15:10:36 +0100 3635246 http://www.medworm.com/index.php?rid=3633375&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2010%2F676243.html A resistant and capable fungal strain in removing hexavalent chromium was isolated from an environment near of Chemical Science Faculty, located in the city of San Luis Potosí, Mexico. The strain was identified as Paecilomyces sp., by macro- and microscopic characteristics. Strain resistance of the strain to high Cr (VI) concentrations and its ability to reduce chromium were studied. When it was incubated in minimal medium with glucose, another inexpensive commercial carbon source like unrefined and brown sugar or glycerol, in the presence of 50 mg/L of Cr (VI), the strain caused complete disappearance of Cr (VI), with the concomitant production of Cr (III) in the growth medium after 7 days of incubation, at 28C°, pH 4.0, 100 rpm, and an inoculum of 38 mg o... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=3633375 Sun, 06 Jun 2010 14:44:37 +0100 3633375 http://www.medworm.com/index.php?rid=3620908&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2010%2F183097.html Novel ruthenium(III) complexes with histamine [RuCl4(dmso-S)(histamineH)]⋅H2O (1a) and [RuCl4(dmso-S)(histamineH)] (1b) have been prepared and characterized by X-ray structure analysis. Their crystal structures are similar and show a protonated amino group on the side chain of the ligand which is not very common for a simple heterocyclic derivative such as histamine. Biological assays to test the cytotoxicity of the compound 1b combined with electroporation were performed to determine its potential for future medical applications in cancer treatment. (Source: Bioinorganic Chemistry and Applications) Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=3620908 Wed, 02 Jun 2010 14:56:46 +0100 3620908 http://www.medworm.com/index.php?rid=3613824&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2010%2F457964.html Fly ash superficially modified with humic substances from the Megalopolis lignitic power plant was prepared and evaluated for agricultural uses. UV-vis spectrophotometry and IR spectroscopy revealed that fly ash shows high sorption efficiency towards humic substances. Adsorption proceeds stepwise via strong Coulombic and hydrophophic forces of attraction between guest and host materials. Langmuir, Freundlich, BET, Harkins-Jura, and Dubinin-Radushkevich isotherm models were employed to evaluate the ongoing adsorption and shed light to the physicochemical properties of the sorbent-adsorbate system. Humic substances desorption and microbial cultivation experiments were also carried out to examine the regeneration of the humates under washing and explore the possibility of this material acclim... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=3613824 Mon, 31 May 2010 14:53:56 +0100 3613824 http://www.medworm.com/index.php?rid=3613823&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2010%2F348692.html The reaction between chromium(III) and 2,3-dihydroxybenzoic acid (2,3-DHBA) takes place in at least three stages, involving various intermediates. The ligand (2,3-DHBA)-to-chromium(III) ratio in the final product of the reaction is 1 : 1. The first stage is suggested to be the reaction of [Cr(H2O)5(OH)]2+ with the ligand in weak acidic aqueous solutions that follows an Id mechanism. The second and third stages do not depend on the concentrations of chromium(III), and their activation parameters are ΔH≠2(obs)=61.2±3.1 kJmol−1, ΔS≠2(obs)=−91.1±11.0 JK−1mol−1, ΔH≠3(obs)=124.5±8.7 kJmol−1, and ΔS≠3(obs)=95.1±29.0 JK−1mol−... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=3613823 Mon, 31 May 2010 14:53:56 +0100 3613823 http://www.medworm.com/index.php?rid=3611825&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2010%2F932569.html Two new compounds that consist of the linear trinuclear manganese(II) cation [Mn3(O2CMe)4(py)8]2+ cocrystallizing with different counteranions (I3-, [1]; ClO4-, [2]) are reported. Complex 1 was prepared from the reaction of [Mn(O2CMe)2]⋅4H2O with I2 in MeCO2H/py, whereas complex 2 was isolated from the reaction of [Mn3O(O2CMe)6(py)3]⋅py with [Mn(ClO4)2]⋅6H2O in MeCN/py. The crystal structures of both compounds were determined by single crystal X-ray crystallography. Magnetic susceptibility studies that were performed in microcrystalline powder of 1 in the 2–300 K range revealed the presence of antiferromagnetic exchange interactions that resulted in an S=5/2 ground spin state. (Source: Bioinorganic Chemistry and Applications) Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=3611825 Sun, 30 May 2010 14:45:07 +0100 3611825 http://www.medworm.com/index.php?rid=3611824&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2010%2F169054.html The flexible ditopic ligand 3,3′-bipyridine (3,3′-bpy) has been reacted with a series of transition metal species (Ag+, Hg2+, cis-a2M2+ (a=NH3 or a2=en; M=Pt,Pd), trans-a2Pt2+ (a=NH3)) in an attempt to produce discrete cyclic constructs. While Ag+ gave a polymeric structure {[Ag(3,3′-bpy)](ClO4) ⋅ H2O}n (1), with all other metal entities cyclic structures were formed. Interestingly, Hg(CH3COO)2 produced a dinuclear complex [Hg(3,3′-bpy)(CH3COO)2]2 ⋅ 3H2O (2), in which the two 3,3′-bpy ligands adopt a cis-orientation of the coordinating pyridyl entities. With cis-(NH3)2Pt2+, a cyclic complex 4 was isolated in crystalline form which, according to HRMS, is a trimer. With trans-(NH3)2Pt2+, different species... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=3611824 Sun, 30 May 2010 14:45:07 +0100 3611824 http://www.medworm.com/index.php?rid=3594969&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2010%2F315056.html Tetramic and tetronic acids are naturally occurring molecules with a variety of biological activities. In this review article, we present the general strategies for the synthesis of these compounds and we reveal the functionalized groups that are responsible for their properties. We also set out their coordinating modes with up-to-date bibliographical references. (Source: Bioinorganic Chemistry and Applications) Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=3594969 Tue, 25 May 2010 15:08:12 +0100 3594969 http://www.medworm.com/index.php?rid=3569514&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2010%2F294169.html Neuronal growth inhibitory factor (GIF), also known as metallothionein (metallothionein-3), impairs the survival and neurite formation of cultured neurons. It is known that the α-β domain-domain interaction of hGIF is crucial to the neuron growth inhibitory bioactivity although the exact mechanism is not clear. Herein, the β(MT3)-β(MT3) mutant and the hGIF-truncated Δ33-35 mutant were constructed, and their biochemical properties were characterized by pH titration, EDTA, and DTNB reactions. Their inhibitory activity toward neuron survival and neurite extension was also examined. We found that the Δ33-35 mutant α-domain containing β-domain-like M3S9 cluster exhibits the function of α-domain with M4S11 cluster in hGIF. These resu... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=3569514 Mon, 17 May 2010 15:23:43 +0100 3569514 http://www.medworm.com/index.php?rid=3555442&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2010%2F718606.html The novel diphenyltin(IV) compound [Ph2(HyFoSc)Sn] (2), where H2HyFoSc (1) is 3-hydroxy-2-formylpyridine semicarbazone, was prepared and characterized by vibrational and NMR (1H, 13C) spectroscopy. The structure of [Ph2(HyFoSc)Sn] was confirmed by single-crystal X-ray crystallography. The doubly deprotonated ligand is coordinated to the tin atom through the enolic-oxygen, the azomethine-nitrogen, and phenolic-oxygen, and so acts as an anionic tridentate ligand with the ONO donors. Two carbon atoms complete the fivefold coordination at the tin(IV) center. Intermolecular hydrogen bonding, C–H→π, and π→π interactions combine to stabilize the crystal structure. Compounds 1 and 2 have been evaluated for antiproliferative activity in vitro against the ce... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=3555442 Wed, 12 May 2010 14:51:33 +0100 3555442 http://www.medworm.com/index.php?rid=3551634&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2010%2F563875.html Bisphosphonates are biologically relevant therapeutics for bone disorders and cancer. Reaction of γ-chlorobutyric acid, phosphorus acid, and phosphorus trichloride without the use of solvent gave the tetrahydrofuranyl-2,2-bisphosphonate sodium salt (Na2H2L). The Na2H2L was isolated, characterized in solution by 1H, 13C, and 31P NMR spectroscopy and in solid state by single X-Ray crystallography. The crystal structure showed that the Na2H2L forms in the crystal infinite two-dimensional sheets stacked one parallel to the other. A comparison of the chelating properties of H2L2− with similar hydroxyl bisphosphonate ligands shows that the strength of the Na–O(furanyl/hydroxyl) bond is directly related to the total charge of the ligand anion. (Source: Bioinorganic Chemistry ... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=3551634 Tue, 11 May 2010 15:22:03 +0100 3551634 http://www.medworm.com/index.php?rid=3533119&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2010%2F725153.html Visible-range circular dichroism titrations were used to study Cu(II) binding properties of Multimetal Binding Site (MBS) of Human Serum Albumin (HSA). The formation of ternary MBS-Cu(II)-Buffer complexes at pH 7.4 was positively verified for sodium phosphate, Tris, and Hepes, the three most common biochemical buffers. The phosphate > Hepes > Tris order of affinities, together with strong spectral changes induced specifically by Tris, indicates the presence of both Buffer-Cu(II) and Buffer-HSA interactions. All complexes are strong enough to yield a nearly 100% ternary complex formation in 0.5 mM HSA dissolved in 100 mM solutions of respective buffers. The effects of warfarin and ibuprofen, specific ligands of hydrophobic pockets I and II in HSA on the Cu(II) bind... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=3533119 Wed, 05 May 2010 15:01:52 +0100 3533119 http://www.medworm.com/index.php?rid=3533118&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2010%2F541829.html The present work comprises the recombinant synthesis of four metallothioneins (MTs) in metal-unsupplemented cultures and the characterization of the recovered metal complexes by means of analytical and spectrometric techniques. The four MTs are two Drosophila (MtnA and MtnB), one yeast (Crs5), and one mouse (mMT1) metallothionein isoforms. These four MTs exhibit distinct metal binding preferences, from a clear Cu-thionein character to a definite Zn-thionein nature, respectively. Although in all cases, the only metal ion present in the purified complexes is Zn2+, our results highlight an inherently different behaviour of those two types of MTs, in conditions that would mimic their synthesis in physiological environments. Therefore, intrinsically different roles can be hypothesized for the c... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=3533118 Wed, 05 May 2010 15:01:52 +0100 3533118 http://www.medworm.com/index.php?rid=3510810&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2010%2F307578.html Ferric ion binding proteins (Fbps) transport FeIII across the periplasm and are vital for the virulence of many Gram negative bacteria. Iron(III) is tightly bound in a hinged binding cleft with octahedral coordination geometry involving binding to protein side chains (including tyrosinate residues) together with a synergistic anion such as phosphate. Niobium compounds are of interest for their potential biological activity, which has been little explored. We have studied the binding of cyclopentadienyl and nitrilotriacetato NbV complexes to the Fbp from Neisseria gonorrhoeae by UV-vis spectroscopy, chromatography, ICP-OES, mass spectrometry, and Nb K-edge X-ray absorption spectroscopy. These data suggest that NbV binds strongly to Fbp and that a dinuclear NbV centre can be readily accommod... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=3510810 Wed, 28 Apr 2010 15:56:43 +0100 3510810 http://www.medworm.com/index.php?rid=3482455&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2010%2F848130.html A starch-urea-based biodegradable coordination polymer modified by transition metal Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) was prepared by polycondensation of starch and urea. All the synthesized polymeric compounds were characterized by Fourier transform-infrared spectroscopy (FT-IR), H1-NMR spectroscopy, C13-NMR spectroscopy, UV-visible spectra, magnetic moment measurements, differential scanning calorimeter (DSC), and thermogravimetric analysis (TGA). The results of electronic spectra and magnetic moment measurements indicate that Mn(II), Co(II), and Ni(II) complexes show octahedral geometry, while Cu(II) and Zn(II) complexes show square planar and tetrahedral geometry, respectively. The thermogravimetric analysis revealed that all the polymeric metal complexes are more thermally s... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=3482455 Mon, 19 Apr 2010 15:21:18 +0100 3482455 http://www.medworm.com/index.php?rid=3440291&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2010%2F182804.html Reduction mechanisms of oxygen molecule to water molecules in the fully reduced (FR) and mixed-valence (MV) bovine cytochrome c oxidases (CcO) have been systematically examined based on the B3LYP calculations. The catalytic cycle using four electrons and four protons has been also shown consistently. The MV CcO catalyses reduction to produce one water molecule, while the FR CcO catalyses to produce two water molecules. One water molecule is added into vacant space between His240 and His290 in the catalytic site. This water molecule constructs the network of hydrogen bonds of Tyr244, farnesyl ethyl, and Thr316 that is a terminal residue of the K-pathway. It plays crucial roles for the proton transfer to the dioxygen to produce the water molecules in both MV and FR CcOs. Tyr244 functions as ... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=3440291 Tue, 06 Apr 2010 16:20:48 +0100 3440291 http://www.medworm.com/index.php?rid=3424088&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2010%2F456240.html In this study, we have followed a tissue-engineering strategy where ultrasonically stimulated SAOS-2 human osteoblasts proliferated and built their extracellular matrix inside a porous hydroxyapatite scaffold. The ultrasonic stimulus had the following parameters: average power equal to 149 mW and frequency of 1.5 MHz. In comparison with control conditions, the ultrasonic stimulus increased the cell proliferation and the surface coating with bone proteins (decorin, osteocalcin, osteopontin, type-I collagen, and type-III collagen). The mechanical stimulus aimed at obtaining a better modification of the biomaterial internal surface in terms of cell colonization and coating with bone matrix. The modified biomaterial could be used, in clinical applications, as an implant for bone ... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=3424088 Wed, 31 Mar 2010 15:48:06 +0100 3424088 http://www.medworm.com/index.php?rid=3415518&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2010%2F386860.html The synthesis and characterization of the silver(I) chloride complex of formula {[AgCI(CMBZT)(TPTP)2]⋅(MeOH)} (1) (CMBZT = 5-chloro-2-mercaptobenzothiazole, TPTP = tris(p-tolyl)phosphine) is described. Also the structure of the hydrate derivative {[AgCI(TPTP)3]⋅(0.5⋅H2O)} (2) of the corresponding known anhydrous silver complex (Zartilas et al., 2009), and the polymorph 3 of the known [AgI(TPTP)3] complex (Zartilas et al., 2009) were determined and compared with the known ones. In addition, the structure of the known one silver(I) cluster {[AgI(TPTP)]4} (4) (Meijboom et al., 2009) was re-determined at 120(2) K and possible Ag-Ag interactions were analyzed. The compounds 1–4 were characterized by X-ray crystallography at r.t (1) and 120 K (2–4). All these com... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=3415518 Mon, 29 Mar 2010 15:30:26 +0100 3415518 http://www.medworm.com/index.php?rid=3353678&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2010%2F724210.html The utility of the extensible systematic force field (ESFF) was tested for copper(II) binding to a 34-amino-acid Cu(II) peptide, which includes five histidine residues and is the putative copper-binding site of lysyl oxidase. To improve computational efficiency, distance geometry calculations were used to constrain all combinations of three histidine ligands to be within bonding distance of the copper and the best results were utilized as starting structures for the ESFF computations. All likely copper geometries were modeled, but the results showed only a small dependence on the geometrical model in that all resulted in a distorted square pyramidal geometry about the copper, some of the imidazole rings were poorly oriented for ligation to the Cu(II), and the copper-nitrogen bond distances... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=3353678 Thu, 11 Mar 2010 17:39:14 +0100 3353678 http://www.medworm.com/index.php?rid=3341873&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2009%2F906836.html Three model dipeptides containing 3-(2,3-di(pyridin-2-yl)quinoxalin-6-yl)alanine, 3-(dipyrido[3,2-a:2,3-c]phenazin-11-yl)alanine, and 3-(2,3-diphenylquinoxalin-6-yl)alanine were studied with respect to their ability to bind selected transition metal ions, such as Cu(II), Fe(II), Ni(II), Co(II), Mn(II), and Cr(III). It was found that only Cu(II) and Fe(II) ions could form stable complex species with the studied compounds. The ability to form the complexes correlated well with DNA damage experiments. Only the ferrous and cupric complexes are capable of generating both single- and double-strand scissions. However, double-strand breakages appear to be dominating lesions in the presence of hydrogen peroxide, especially for copper(II) containing systems. The quantity of breakage products in the ... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=3341873 Mon, 08 Mar 2010 17:30:27 +0100 3341873 http://www.medworm.com/index.php?rid=3211615&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2009%2F901563.html This study reports a new material for the removal of heavy metals from low-strength wastewater. (Source: Bioinorganic Chemistry and Applications) Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=3211615 Wed, 27 Jan 2010 16:02:03 +0100 3211615 http://www.medworm.com/index.php?rid=3106598&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2009%2F925297.html The composition and morphology of nanocrystals in urines of healthy persons and lithogenic patients were comparatively investigated by means of X-ray diffraction (XRD) and transmission electron microscopy (TEM). It was shown that the main composition of urinary nanocrystals in healthy persons were calcium oxalate dihydrate (COD), uric acid, and ammonium magnesium phosphate (struvite). However, the main compositions of urinary nanocrystals in lithogenic patients were struvite, β-tricalcium phosphate, uric acid, COD, and calcium oxalate monohydrate (COM). According to the XRD data, the size of nanocrystals was calculated to be 23∼72 nm in healthy urine and 12∼118 nm in lithogenic urine by Scherer formula. TEM results showed that the nanocrystals in healthy ... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=3106598 Sun, 20 Dec 2009 15:45:03 +0100 3106598 http://www.medworm.com/index.php?rid=2971797&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2008%2F647873.html The new complexes [M2O5L2(H2O)2]⋅H2O (M=Mo,1;M=W,2), [RuL2(H2O)2]⋅H2O  (3), [ML3]⋅xH2O (M=Rh,x=2,4;M=Ir,x=1,5), [RhL2(PPh3)2](ClO4)⋅2H2O  (6), [PdL2]⋅2H2O  (7), [PdL(phen)]Cl⋅H2O  (8), [Re⁡OL2(PPh3)]Cl  (9) and [UO2L2]  (10) are reported, where LH is 4,6-diamino-1-hydro-5-hydroxy-pyrimidine-2-thione. The complexes were characterized by elemental analyses, physical techniques (molar conductivity, room-temperature magnetic susceptibility), and spectroscopic (IR, Raman, UV/VIS/ligand field, NMR, mass) methods. The ligand L− is in its thione form and behaves as a bidentate chelate with the deprotonated (hydroxyl) oxygen and the nitrogen ... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=2971797 Sun, 08 Nov 2009 15:49:27 +0100 2971797 http://www.medworm.com/index.php?rid=2971796&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2009%2F702730.html A neutral compound Re(CO)3(L) (L: 2-((2-(2,6-diethylphenylamino)-2-oxoethyl)(2-ethoxy-2-oxoethyl)amino)acetic acid, an IDA analogue) has been synthesized and evaluated for in vitro imaging probes of β-amyloid (Aβ) aggregates. Results of X-ray measurement of Re(CO)3(L) demonstrated that the coordination mode of Re(CO)3(L) was different from that of classical Re/Tc(I) (tricarbonyl)-IDA analogues; the structure of Re(CO)3(L) was confirmed by means of infrared spectrum, HPLC-UV, TOF MS, and X-ray measurements (Cambridge Crystallographic Data Centre number is 732731): monoclinic P21/c, a=15.6636 (12) Å, b=10.9360 (8) Å, c=27.756 (2) Å, α=90.000 (0)∘, β=90.783 (5)∘, γ=90.000 (0)∘, and Z=8. The binding af... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=2971796 Sun, 08 Nov 2009 15:49:27 +0100 2971796 http://www.medworm.com/index.php?rid=2926771&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2009%2F413175.html Three new Schiff bases of N-substituted isatin LI, LII, and LIII = Schiff base of N-acetylisatin, N-benzylisatin, and N-benzoylisatin, respectively, and their metal complexes C1a,b=[Co2(LI)2Cl3]Cl, C2=[Ni(LI)2Cl2]0.4BuOH, C3=[CuLICl(H2O)]Cl⋅0.5BuOH, C4=[Pd(LI)2Cl]Cl, C5=[Pt(L1)2Cl2]Cl2⋅1.8EtOH.H2O, C6a=[CoLIICl]Cl⋅0.4H2O⋅0.3DMSO, C6b=[CoLIICl]Cl⋅0.3H2O⋅0.1BuOH, C7=[NiLIICl2], C8=[CuLII]Cl2⋅H2O , C9=[Pd(LII)2]Cl2, C10=[Pt(LII)2.5Cl]Cl3, C11a=[Co(LIII)]C12⋅H2O, C11b=[Co(LIII)]Cl2⋅0.2H2O, and C12=[Ni(LIII)2]Cl2, C13=[Ni(LIII)2]Cl2 were reported. The complexes were characterized by elemental analyses, metal and chloride content, spectroscopic methods, magnetic moments, conductivity measurements, and thermal s... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=2926771 Mon, 26 Oct 2009 16:23:40 +0100 2926771 http://www.medworm.com/index.php?rid=2875135&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2009%2F347872.html Complexes of copper (II) with hesperetin, naringenin, and apigenin of general composition [CuL2(H2O)2]⋅nH2O (1–3) have been synthesized and characterized by elemental analysis, UV-Vis, FT-IR, ESI-MS, and TG-DTG thermal analysis. The free ligands and the metal complexes have been tested in vitro against human cancer cell lines hepatocellular carcinoma (HepG-2), gastric carcinomas (SGC-7901), and cervical carcinoma (HeLa). Complexes 1 and 3 were found to exhibit growth inhibition of SGC-7901 and HepG2 cell lines with respect to the free ligands; the inhibitory rate of complex 1 is 43.2% and 43.8%, while complex 3 is 46% and 36%, respectively. The interactions of complex 1 and its ligand Hsp with calf thymus DNA were investigated by UV-Vis, fluorescence, and CD s... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=2875135 Fri, 09 Oct 2009 11:06:39 +0100 2875135 http://www.medworm.com/index.php?rid=2836028&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2009%2F347359.html Fine structures of 8-G-1-(p-YC6H4C ≡ CSe)C10H6 [1 (G = H) and 2 (G = Cl): Y = H (a), OMe (b), Me (c), F (d), Cl (e), CN (f), and NO2 (g)] are determined by the X-ray analysis. Structures of 1, 2, and 3 (G = Br) are called A if each Se–Csp bond is perpendicular to the naphthyl plane, whereas they are B when the bond is placed on the plane. Structures are observed as A for 1a–c bearing Y of nonacceptors, whereas they are B for 1e–g with Y of strong acceptors. The change in the structures of 1e–g versus those of 1a–c is called Y-dependence in 1. The Y-dependence is very specific in 1 relative to 1-(p-YC6H4Se)C10H7 (4) due to the ethynyl group: the Y-dependence in 1 is almost inverse to the case of 4 due to the ethynyl group. We call the speci... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=2836028 Sun, 27 Sep 2009 18:02:26 +0100 2836028 http://www.medworm.com/index.php?rid=2799853&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2009%2F303176.html Nanorods hydroxyapatite, (HAP) Ca10(PO4)6(OH)2 is successfully prepared by water in oil microemulsion using, CaCL2 and H3PO4 (water phase), poly(sodium 4-styrene sulfonate) (PSSS) as template and cyclohexane as oil phase. The nano-structure of the product was studied by means of X-ray diffraction (XRD), Fourier transmission infrared spectrometer (FT-IR), scanning electron microscopy (SEM), and atomic force microscope (AFM). With this system, we could synthesize nano-particles of hydroxyapatite with high crystallinity and least agglomeration. (Source: Bioinorganic Chemistry and Applications) Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=2799853 Wed, 16 Sep 2009 17:46:59 +0100 2799853 http://www.medworm.com/index.php?rid=2770045&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2009%2F979680.html The absorption efficiency of any drug in blood is of prime importance. Compounds having the general formula: Kn[M(FO)2(H2O)2]⋅xH2O, where (M=Cu(II) or Fe(III), n=2 or 1 , FO=folate anion, x=2 or 3 with respect), were prepared, and their absorption efficiency in rodent's blood was determined. The obtained compounds were characterized by elemental analysis, infrared as well as thermogravimetric analysis and polarization of light. The results suggest that the two folate complexes were formed in 1 : 2 molar ratio (metal : folic acid) which acted as a bidentate ligand through both carboxylic groups. Polarization of light proved that the folate complexes have symmetric geometry. Biological application proved that Cu(II) and Fe(III) complexes were absorbed more efficiently in rodent bl... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=2770045 Sun, 06 Sep 2009 17:41:38 +0100 2770045 http://www.medworm.com/index.php?rid=2704956&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2009%2F512938.html The [Pd(DEEN)Cl2] and [Pt(DEEN)Cl2] complexes were synthesized and characterized where DEEN=N,N-diethylethylenediamine. The stoichiometry and stability of the complexes formed between various biologically relevant ligands (amino acids, peptides, DNA constituents and dicarboxylic acids) and [Pd(DEEN)(H2O)2]2+ were investigated at 37∘C and 0.16 M ionic strength. The stability constant of the complexes formed in solution were determined and the binding centres of the ligands were assigned. The concentration distribution diagrams of the complexes were evaluated The equilibrium constants for the displacement of representative coordinated ligands such as inosine, glycine or methionine by cysteine were calculated and the concentration distribution diagrams of the various species wer... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=2704956 Mon, 17 Aug 2009 11:30:05 +0100 2704956 http://www.medworm.com/index.php?rid=2694588&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2009%2F561091.html Dead dried Chlorella vulgaris was studied in terms of its performance in binding divalent copper, cadmium, and lead ions from their aqueous or 50% v/v methanol, ethanol, and acetone solutions. The percentage uptake of cadmium ions exhibited a general decrease with decrease in dielectric constant values, while that of copper and lead ions showed a general decrease with increase in donor numbers. Uptake percentage becomes less sensitive to solvent properties the larger the atomic radius of the biosorbed ion, and uptake of copper was the most affected. FT-IR analyses revealed stability of the biomass in mixed solvents and a shift in vibrations of amide(I) and (II), carboxylate, glucose ring, and metal oxygen upon metal binding in all media. ΔνCOO values (59–69 c... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=2694588 Thu, 13 Aug 2009 12:14:53 +0100 2694588 http://www.medworm.com/index.php?rid=2673859&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2009%2F381925.html Nuclear couplings for the Se-Se bonds, J1(Se, Se), are analyzed on the basis of the molecular orbital (MO) theory. The values are calculated by employing the triple ζ basis sets of the Slater type at the DFT level. J1(Se, Se) are calculated modeled by MeSeSeMe (1a), which shows the typical torsional angular dependence on ϕ(CMeSeSeCMe). The dependence explains well the observed J1(Se, Se)obsd of small values (≤64 Hz) for RSeSeR′ (1) (simple derivatives of 1a) and large values (330–380 Hz) observed for 4-substituted naphto[1,8-c,d]-1,2-diselenoles (2) which correspond to symperiplanar diselenides. J1 (Se, Se : 2) becomes larger as the electron density on Se increases. The paramagnetic spin-orbit terms contribute predominantly. The contributions are ev... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=2673859 Thu, 06 Aug 2009 12:11:45 +0100 2673859 http://www.medworm.com/index.php?rid=2663718&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2009%2F914105.html The present work comprises the synthesis of enoxacin (Heno) complexes with various transition metals. Two types of complexes [M(eno)2(H2O)2]3H2O(M=CuII, NiII or MnII) and [M(eno)(H2O)2]Cl⋅4H2O  (M=FeIII) were obtained. The complexes were characterized by different physicochemical, spectroscopic, and elemental analysis. Results suggest that enoxacin interacts with the metals as a monoanionic bidentate ligand. These complexes were also tested for their antibacterial activity against eleven (11) different microorganisms, and the results were compared with the parent drug. Moreover all the metal complexes were also tested for their ability to scavenge reactive oxygen species where by MnII and CuII complexes exhibited potential to mediate anti-inflammatory response. ... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=2663718 Mon, 03 Aug 2009 12:11:53 +0100 2663718 http://www.medworm.com/index.php?rid=2572686&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2009%2F905320.html The synthesis and characterization of a novel ligand, bis[(2-ethyl-5-methyl-imidazo-4-yl)methyl]sulfide (bemims), as well as a bemims-containing copper(II) coordination complex are described. In this complex, [Cu(bemims)X2] with X=NO3-, bemims acts as a tridentate ligand and two monodentate nitrate ions complete the coordination sphere. Both imidazole N atoms and the thioether S atom of bemims participate in coordination. The Cu(II) ion is five-coordinated with a slightly distorted square-pyramidal geometry (τ=.09). Electrochemical studies and spectroscopic data for this complex are compared with some blue copper proteins in order to assess its ability to mimic the copper center of type I copper proteins. (Source: Bioinorganic Chemistry and Applications) Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=2572686 Mon, 06 Jul 2009 11:53:47 +0100 2572686 http://www.medworm.com/index.php?rid=2572685&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2009%2F219818.html The sequestering ability of polyamines and aminoacids of biological and environmental relevance (namely, ethylenediamine, putrescine, spermine, a polyallylamine, a branched polyethyleneimine, aspartate, glycinate, lysinate) toward dimethyltin(IV) cation was evaluated. The stability of various dimethyltin(IV) / ligand species was determined in NaClaq at t=25∘C and at different ionic strengths (0.1≤I/mol L-1≤1.0), and the dependence of stability constants on this parameter was modeled by an Extended Debye-Hückel equation and by Specific ion Interaction Theory (SIT) approach. At I=0.1 mol L−1, for the ML species we have log K=10.8, 14.2, 12.0, 14.7, 11.9, 7.7, 13.7, and 8.0 for ethylenediamine, putrescine, polyallylamine, spermine, polyethyleneimine, gl... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=2572685 Mon, 06 Jul 2009 11:53:47 +0100 2572685 http://www.medworm.com/index.php?rid=2503429&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2009%2F603651.html A mixed copper complex with deprotonated nalidixic acid (nal) and histamine (hsm) was synthesized and characterized by FTIR, UV-Vis, elemental analysis, and conductivity. The crystal structure of [Cu(hsm)(nal)H2O]Cl·3H2O (chn) showed a pentacoordinated cooper(II) in a square pyramidal geometry surrounded by two N atoms from hsm, two O atoms from the quinolone, and one apical water oxygen. Alteration of bacterial DNA structure and/or associated functions in vivo by [Cu(hsm)(nal)H2O]Cl·3H2O was demonstrated by the induction of a recA-lacZ fusion integrated at the amyE locus of a recombinant Bacillus subtilis strain. Results from circular dichroism and denaturation of calf thymus DNA (CT-DNA) suggested that increased amounts of copper complex were able to stabilize the double h... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=2503429 Thu, 25 Jun 2009 08:46:07 +0100 2503429 http://www.medworm.com/index.php?rid=2467875&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2007%2F091078.abs.html The interaction of drugs with DNA is an important aspect in pharmacology. In recent years, many important technological advances have been made to develop new techniques to monitor biorecognition and biointeraction on solid devices. The interaction between DNA and drugs can cause chemical and conformational modifications and, thus, variation of the electrochemical properties of nucleobases. The propensity of a given compound to interact with DNA is measured as a function of the decrease of guanine oxidation signal on a DNA electrochemical biosensor. Covalent binding at N7 of guanine, electrostatic interactions, and intercalation are the events that this kind of biosensor can detect. In this context, the interaction between a panel of antitumoral Pt-, Ru-, and Ti-based metallodrugs with DNA... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=2467875 Wed, 10 Jun 2009 02:31:38 +0100 2467875 http://www.medworm.com/index.php?rid=2467874&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2007%2F051483.abs.html A series of metal complexes of Cu(II) and Ni(II) having the general composition [M(L)X2] with benzil bis(thiosemicarbazone) has been prepared and characterized by element chemical analysis, molar conductance, magnetic susceptibility measurements, and spectral (electronic, IR, EPR, mass) studies. The IR spectral data suggest the involvement of sulphur and azomethane nitrogen in coordination to the central metal ion. On the basis of spectral studies, an octahedral geometry has been assigned for Ni(II) complexes but a tetragonal geometry for Cu(II) complexes. The free ligand and its metal complexes have been tested in vitro against a number of microorganisms in order to assess their antimicrobial properties. (Source: Bioinorganic Chemistry and Applications) Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=2467874 Wed, 10 Jun 2009 02:31:38 +0100 2467874 http://www.medworm.com/index.php?rid=2467873&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2007%2F010720.abs.html The 173–195 segment corresponding to the helix 2 of the C-globular prion protein domain could be one of several “spots” of intrinsic conformational flexibility. In fact, it possesses chameleon conformational behaviour and gathers several disease-associated point mutations. We have performed spectroscopic studies on the wild-type fragment 173–195 and on its D178N mutant dissolved in trifluoroethanol to mimic the in vivo system, both in the presence and in the absence of metal cations. NMR data showed that the structure of the D178N mutant is characterized by two short helices separated by a kink, whereas the wild-type peptide is fully helical. Both peptides retained these structural organizations, as monitored by CD, in the presence of metal cations. NMR spectra were... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=2467873 Wed, 10 Jun 2009 02:31:38 +0100 2467873 http://www.medworm.com/index.php?rid=2467872&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2007%2F030394.abs.html Terminally protected pentapeptides with 2 histidines (Ac-HHVGD-NH2 and Ac-HVGDH-NH2) and the terminally free peptides containing both internal aspartyl and C-terminal histidyl residues (FDAH and VIDAH) have been synthesized, and copper(II) complexes studied by potentiometric, UV-Vis, CD, and EPR spectroscopic techniques in solution. Both thermodynamic and spectroscopic data reveal that side chain donor atoms of aspartyl and histidyl residues have a significant contribution to the metal binding affinity of peptide molecules. In the case of terminally protected peptides, the role of the imidazole-N donor functions is reflected in the enhanced stability of the 3N and 4N coordinated copper(II) complexes. The amino and β-carboxylate groups of FDAH and VIDAH create a very effec... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=2467872 Wed, 10 Jun 2009 02:31:38 +0100 2467872 http://www.medworm.com/index.php?rid=2467871&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2007%2F053521.abs.html Interactions between sinefungin and copper(II) ions were investigated. Stoichiometry and stability constants of the metal-free system and two mononuclear complexes present in solution were determined on the basis of potentiometric data analysis. The results were compared to the Cu(II)-ornithine system due to structural similarities between both molecules. Combined spectroscopic and theoretical studies allowed for determination of coordination pattern for the Cu(II)-sinefungin complexes. At acidic pH, copper is bound in “glycine-like” coordination mode, identical with that of ornithine. This involves α-amino group and the carboxyl oxygen. At higher pH, a “bis-complex” is formed by two sinefungin molecules. The second ligand binds in equatorial position d... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=2467871 Wed, 10 Jun 2009 02:31:38 +0100 2467871 http://www.medworm.com/index.php?rid=2467870&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2007%2F096536.abs.html Solution equilibrium studies on Fe(III) complexes formed with imidazole-4-carbohydroxamic acid (Im-4-Cha), N-Me-imidazole-4-carbohydroxamic acid (N-Me-Im-4-Cha), imidazole-4-acetohydroxamic acid (Im-4-Aha), and histidinehydroxamic acid (Hisha) have been performed by using pH-potentiometry, UV-visible spectrophotometry, EPR, ESI-MS, and H1-NMR methods. All of the obtained results demonstrate that the imidazole moiety is able to play an important role very often in the interaction with Fe(III), even if this metal ion prefers the hydroxamate chelates very much. If the imidazole moiety is in α-position to the hydroxamic one (Im-4-Cha and N-Me-Im-4-Cha) its coordination to the metal ion is indicated unambiguously by our results. Interestingly, parallel formation of (Nimidazole, Ohydrox... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=2467870 Wed, 10 Jun 2009 02:31:38 +0100 2467870 http://www.medworm.com/index.php?rid=2467869&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2007%2F051567.abs.html The 12: 1 reaction of urea (U) with CoI2 in EtOH yielded the “clathrate-coordination” compound [CoU6]I2·4U (1). The complex crystallizes in the monoclinic space group P21/c. The lattice constants are a = 9.844(4), b = 7.268(3), c = 24.12(1) Å, and β=98.12(1)∘. The crystal structure determination demonstrates the existence of octahedral [CoU6]2+ cations, I- counterions, and two different types (two U1 and two U2) of hydrogen-bonded, lattice urea molecules. The [CoU6]2+ cations and the U1 lattice molecules form two-dimensional hydrogen-bonded layers which are parallel to the ab plane. The I- anions are placed above and below each layer, and are hydrogen bonded both to U1 molecules and [CoU6]2+ cations. Each U2 molecule is connected to a [CoU6]2+ cati... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=2467869 Wed, 10 Jun 2009 02:31:38 +0100 2467869 http://www.medworm.com/index.php?rid=2467868&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2008%2F479897.html A new series of Zn2+, Cu2+, Ni2+, and Co2+ complexes of N1-methyl-2-(1H-1,2,3-benzotriazol-1-yl)-3-oxobutanethioamide (MBOBT), HL, has been synthesized and characterized by different spectral and magnetic measurements and elemental analysis. IR spectral data indicates that (MBOBT) exists only in the thione form in the solid state while 13C NMR spectrum indicates its existence in thione and thiole tautomeric forms. The IR spectra of all complexes indicate that (MBOBT) acts as a monobasic bidentate ligand coordinating to the metal(II) ions via the keto-oxygen and thiolato-sulphur atoms. The electronic spectral studies showed that (MBOBT) bonded to all metal ions through sulphur and nitrogen atoms based on the positions and intensity of their charge transfer bands. Furthermore, the spectra... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=2467868 Wed, 10 Jun 2009 02:31:38 +0100 2467868 http://www.medworm.com/index.php?rid=2467867&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2008%2F294756.html The formation of the DNA G-quadruplex is induced by the addition of a novel porphyrin carrying four cationic tethers. Circular dichroism spectroscopy reveals that the porphyrin binds to Tetrahymena telomeric repeat to form G-quadruplex under stabilizing-cation-deficient and no buffer conditions. (Source: Bioinorganic Chemistry and Applications) Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=2467867 Wed, 10 Jun 2009 02:31:38 +0100 2467867 http://www.medworm.com/index.php?rid=2467866&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2008%2F654137.html A novel tri-n-butyl(IV) derivative of 2-thiobarbituric acid (HTBA) of formula [(n-Bu)3Sn(TBA)⋅H2O] (1) has been synthesized and characterized by elemental analysis and 119Sn-NMR and FT-IR spectroscopic techniques. The crystal structure of complex 1 has been determined by single crystal X-ray diffraction analysis at 120(2) K. The geometry around Sn(IV) is trigonal bipyramidal. Three n-butyl groups and one oxygen atom from a deprotonated 2-thiobarbituric ligand are bonded to the metal center. The geometry is completed with one oxygen from a water molecule. Compound 1 exhibits potent, in vitro, cytotoxicity against sarcoma cancer cells (mesenchymal tissue) from the Wistar rat, polycyclic aromatic hydrocarbons (PAH, benzo[a]pyrene) carcinogenesis. In addition, the inhi... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=2467866 Wed, 10 Jun 2009 02:31:38 +0100 2467866 http://www.medworm.com/index.php?rid=2467865&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2008%2F257038.html The N- and C-terminal blocked hexapeptide Ac-Leu-Ala-His-Tyr-Asn-Lys-amide (LAHYNK) representing the 80–85 fragment of histone H2B was synthesized and its interactions with Cu(II) and Ni(II) ions were studied by potentiometric, UV-Vis, CD, EPR, and NMR spectroscopic techniques in solution. Our data reveal that the imidazole N(3) nitrogen atom is the primary ligating group for both metal ions. Sequential amide groups deprotonation and subsequent coordination to metal ions indicated an {Nimidazole,3Namide} coordination mode above pH∼9, in all cases. In the case of Cu(II)-peptide system, the almost exclusive formation of the predominant species CuL in neutral media accounting for almost 98% of the total metal ion concentration at pH 7.3 strongly indicates that at physiologica... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=2467865 Wed, 10 Jun 2009 02:31:38 +0100 2467865 http://www.medworm.com/index.php?rid=2467864&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2008%2F420578.html In this study we analyzed blood and urine samples from shipyard industry welders being exposed to different levels of Cr(VI) over a period of five months in order to assay in vivo the relation of ApoJ/CLU serum levels with Cr(VI). Our findings confirmed the previously reported in vitro data since reduction of Cr levels, after a worksite intervention, associated with lower levels of ApoJ/CLU serum levels. We concluded that the human ApoJ/CLU gene is responsive to the acute in vivo oxidative stress induced by heavy metals such as hexavalent chromium. (Source: Bioinorganic Chemistry and Applications) Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=2467864 Wed, 10 Jun 2009 02:31:38 +0100 2467864 http://www.medworm.com/index.php?rid=2467863&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2008%2F469062.html Molecular dynamics simulation of the interaction between the Tenebrio molitor alpha-amylase and its inhibitor at different proportion of crystal water was carried out with OPLS force field by hyperchem 7.5 software. In the correlative study, the optimal temperature of wheat monomeric and dimeric protein inhibitors was from 273 K to 318 K. The the average temperature of experimentation is 289 K. (1) The optimal temperature of interaction between alpha-amylase and its inhibitors was 280 K without crystal water that was close to the results of experimentation. The forming of enzyme-water and inhibitor-water was easy, but incorporating third monomer was impossible. (2) Having analyzed the potential energy data, the optimal temperature of interaction energy between a... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=2467863 Wed, 10 Jun 2009 02:31:38 +0100 2467863 http://www.medworm.com/index.php?rid=2467862&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2008%2F367471.html The antineoplastic potential of a stable monomeric Au(II) complex with hematoporphyrin IX (Hp), namely [Au(II)Hp-2H.(H2O)2], was investigated in a panel of tumor cell lines. The complex exhibits strong cytotoxicity, whereby the leukaemia- and lymphoma-derived cell lines are more sensitive, with IC50 values comparable to those of the reference anticancer drug cisplatin. In contrast, the solid tumor models are more sensitive to the platinum drug. A comparative assessment of both agents against the human kidney cell line 293T has shown that [Au(II)Hp-2H.(H2O)2] is less cytotoxic. The gold complex induces oligonucleosomal DNA fragmentation in tumour cells following 24-hour treatment and hence its cytotoxic effect is at least partly mediated by induction of apoptotic cell death. A prominent int... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=2467862 Wed, 10 Jun 2009 02:31:38 +0100 2467862 http://www.medworm.com/index.php?rid=2467861&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2008%2F539082.html The trivalent arsenic glutathione complexes arsenic triglutathione, methylarsonous diglutathione, and dimethylarsinous glutathione are key intermediates in the mammalian metabolism of arsenite and possibly represent the arsenic species that are transported from the liver to the kidney for urinary excretion. Despite this, the comparative stability of the arsenic-sulfur bonds in these complexes has not been investigated under physiological conditions resembling hepatocyte cytosol. Using size-exclusion chromatography and a glutathione-containing phosphate buffered saline mobile phase (5 or 10 mM glutathione, pH 7.4) in conjunction with an arsenic-specific detector, we chromatographed arsenite, monomethylars... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=2467861 Wed, 10 Jun 2009 02:31:38 +0100 2467861 http://www.medworm.com/index.php?rid=2467860&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2008%2F983725.html A sequence of stages in the syntheses of isomeric bisamino acid complexes of Pt(II) with β-aminopropionic acid (β-alanine = β-AlaH) has been studied by the P195t NMR spectroscopy. The techniques have been developed of the synthesis of the cis- and trans-bischelates of Pt(II) and Pd(II) with β-alanine as well as of the halide complexes of trans-[M(β-AlaH)2Cl2] (M = Pt, Pd) and trans-K2[Pt(β-Ala)2I2] types. The NMR spectroscopy and IR spectroscopy (in the nuclei of P195t,C13,H1) and X-ray diffraction analysis have been used to examine the structures of the synthesized compounds. (Source: Bioinorganic Chemistry and Applications) Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=2467860 Wed, 10 Jun 2009 02:31:38 +0100 2467860 http://www.medworm.com/index.php?rid=2467859&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2008%2F576297.html Class B β-lactamases or metallo-β-lactamases (MBLs) require zinc ions to catalyse the hydrolysis of β-lactam antibiotics such as penicillins, cephalosporins, carbapenems, and cephamycins. There are no clinically useful inhibitors against MBLs which are responsible for the resistance of some bacteria to antibiotics. There are two metal-ion binding sites that have different zinc ligands but the exact roles of the metal-ion remain controversial, and distinguishing between their relative importance is complex. The metal-ion can act as a Lewis acid by co-ordination to the β-lactam carbonyl oxygen to facilitate nucleophilic attack and stabilise the negative charge developed on this oxygen in the tetrahedral intermediate anion. The metal-ion also lowers the pKa of the ... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=2467859 Wed, 10 Jun 2009 02:31:38 +0100 2467859 http://www.medworm.com/index.php?rid=2467858&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2008%2F624583.html Our study of the complexation of 3,4-dihydroxy-phenyl-propenoic acid by chromium(III) could give information on the way that this metal ion is available to plants. The reaction between chromium(III) and 3,4-dihydroxy-phenyl-propenoic acid in weak acidic aqueous solutions has been shown to take place by at least three stages. The first stage corresponds to substitution (Id mechanism) of water molecule from the Cr(H2O)5OH2+ coordination sphere by a ligand molecule. A very rapid protonation equilibrium, which follows, favors the aqua species. The second and the third stages are chromium(III) and ligand concentration independent and are attributed to isomerisation and chelation processes. The corresponding activation parameters are ΔH2(obs)≠ = 28.6 ± 2.9 kJ mol&#x22... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=2467858 Wed, 10 Jun 2009 02:31:38 +0100 2467858 http://www.medworm.com/index.php?rid=2467857&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2008%2F253971.html Interactions between aspartic acid (Asp) and cytidine-5-monophosphate (CMP) in metal-free systems as well as the coordination of Cu(II) ions with the above ligands were studied. The composition and overall stability constants of the species formed in those systems were determined by the potentiometric method, and the interaction centres in the ligands were identified by the spectral methods UV-Vis, EPR, NMR, and IR. In metal-free systems, the formation of adducts, in which each ligand has both positive and negative reaction centres, was established. The main reaction centres in Asp are the oxygen atoms of carboxyl groups and the nitrogen atom of the amine group, while the main reaction centre in CMP at low pH is the N(3) atom. With increasing pH, the efficiency of the phosphate group of th... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=2467857 Wed, 10 Jun 2009 02:31:38 +0100 2467857 http://www.medworm.com/index.php?rid=2467856&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2008%2F762029.html The biomimetic catalytic oxidations of the dinuclear and trinuclear copper(II) complexes versus two catechols, namely, D-(+)-catechin and L-(−)-epicatechin to give the corresponding quinones are reported. The unstable quinones were trapped by the nucleophilic reagent, 3-methyl-2-benzothiazolinone hydrazone (MBTH), and have been calculated the molar absorptivities of the different quinones. The catalytic efficiency is moderate, as inferred by kinetic constants, but the complexes exhibit significant enantio-differentiating ability towards the catechols, albeit for the dinuclear complexes, this enantio-differentiating ability is lower. In all cases, the preferred enantiomeric substrate is D-(+)-catechin to respect the other catechol, because of the spatial disposition of this s... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=2467856 Wed, 10 Jun 2009 02:31:38 +0100 2467856 http://www.medworm.com/index.php?rid=2467855&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2008%2F436458.html Formation of silver citrate/citric acid complexed solutions was investigated. Although, silver citrate is minimally soluble in water, it can successfully be dissolved in citric acid solutions. The maximum concentration of Ag(I) in solution is estimated at 23 to 25 g/L if the concentration of citric acid is at least 4 mol/L or higher. The dissolution of silver citrate in citric acid solutions was attributed to the formation of silver citrate complexes of a general formula [Ag3(C6H5O7)n+1]3n−. The silver citrate/citric acid solutions, containing more than about 13 g/L Ag+ ion, have exhibited a decrease in Ag(I) concentration in solution over time, due to crystallization. The crystallization product was attributed to the formation of [Ag3C6H5O7]x⋅nH2O. Impor... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=2467855 Wed, 10 Jun 2009 02:31:38 +0100 2467855 http://www.medworm.com/index.php?rid=2467854&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2008%2F706240.html In order to investigate the behavior of rare earth elements (REEs) and uranium (U) in marine organism, the concentrations of REEs and U in some brown algae samples taken on the coast of Niigata Prefecture were determined. In addition, laboratory model experiment to uptake these elements using living and dried algae (Undaria pinnatifida and Sargassum hemiphyllum) was also carried out to survey the uptake and bioaccumulation mechanism of REEs and U in algae. Consequently, the following matters have been mainly clarified. (1) The order of the concentration of REEs for each organ in Sargassum hemiphyllum is “main branch” > “leaf” > “vesicle,” however for U, the order is “leaf” > “vesicle” > “main branch.” (... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=2467854 Wed, 10 Jun 2009 02:31:38 +0100 2467854 http://www.medworm.com/index.php?rid=2467853&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2008%2F690952.html The palladium(II) bis-chelate Pd (L1−3)2 and platinum(II) tetranuclear Pt4(L4)4 complexes of benzaldehyde thiosemicarbazone derivatives have been synthesized, and characterized by elemental analysis and IR, FAB(+)-mass and NMR (1H,13C) spectroscopy. The complex Pd(L2)2 [HL2=m-CN-benzaldehyde thiosemicarbazone] shows a square-planar geometry with two deprotonated ligands (L) coordinated to PdII through the nitrogen and sulphur atoms in a trans arrangement, while the complex Pt4(L4)4 [HL4=4-phenyl-1-benzaldehyde thiosemicarbazone] has a tetranuclear geometry with four tridentate ligands coordinated to four PtII ions through the carbon (aromatic ring), nitrogen, and sulphur atoms where the ligands are deprotonated at the NH group. The in vitro antitumor activity of the ligands and thei... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=2467853 Wed, 10 Jun 2009 02:31:38 +0100 2467853 http://www.medworm.com/index.php?rid=2467852&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2008%2F501021.html (6-(cyclohexylamino)-1,3-dimethyl-5(2-pyridyl)furo[2,3-d]pyrimidine-2,4(1H,3H)-dione) abbreviated as CDP was synthesized and characterized. Ti(IV), Zn(II), Fe(III), and Pd(II) metal complexes of this ligand are prepared by the reaction of salts of Ti(IV), Zn(II), Fe(III), and Pd(II) with CDP in acetonitrile. Characterization of the ligand and its complexes was made by microanalyses, FT-IR, 1H NMR, 13C NMR, and UV-Visible spectroscopy. All complexes were characterized by several techniques using elemental analysis (C, H, N), FT-IR, electronic spectra, and molar conductance measurements. The elemental analysis data suggest the stoichiometry to be 1:1 [M:L] ratio formation. The molar conductance measurements reveal the presence of 1:1 electrolytic nature complexes. These new complexes showed ... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=2467852 Wed, 10 Jun 2009 02:31:38 +0100 2467852 http://www.medworm.com/index.php?rid=2467851&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2008%2F547915.html In this report, we present the complexation reactions of 3-ethoxycarbonyl tetronic acids with acetates and chlorides of Cu(II) and Co(II). These complexes have been studied by means of EPR spectroscopy and magnetic susceptibility measurements. From the obtained results, a preliminary complexation mode of the ligand is proposed. (Source: Bioinorganic Chemistry and Applications) Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=2467851 Wed, 10 Jun 2009 02:31:38 +0100 2467851 http://www.medworm.com/index.php?rid=2467850&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2008%2F212461.html The interactions between chromium(III) and 3,4-dihydroxybenzoic acid (3,4-DHBA) were studied resulting in the formation of oxygen-bonded complexes upon substitution of water molecules in the chromium(III) coordination sphere. The experimental results show that the reaction takes place in at least three stages, involving various intermediates. The first stage was found to be linearly dependent on ligand concentration k1(obs)_=k0+k1(obs)[3,4-DHBA], and the corresponding activation parameters were calculated as follows: ΔH1(obs)≠=51.2±11.5 kJ mol−1, ΔS1(obs)≠=−97.3±28.9 J mol−1 K−1 (composite activation parameters) . The second and third stages, which are kinetically indistinguishable... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=2467850 Wed, 10 Jun 2009 02:31:38 +0100 2467850 http://www.medworm.com/index.php?rid=2467849&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2008%2F647873.html The new complexes [M2O5L2(H2O)2]⋅H2O (M=Mo,1;M=W,2), [RuL2(H2O)2]⋅H2O  (3), [ML3]⋅xH2O (M=Rh,x=2,4;M=Ir,x=1,5), [RhL2(PPh3)2](ClO4)⋅2H2O  (6), [PdL2]⋅2H2O  (7), [PdL(phen)]Cl⋅H2O  (8), [Re⁡OL2(PPh3)]Cl  (9) and [UO2L2]  (10) are reported, where LH is 4,6-diamino-1-hydro-5-hydroxy-pyrimidine-2-thione. The complexes were characterized by elemental analyses, physical techniques (molar conductivity, room-temperature magnetic susceptibility), and spectroscopic (IR, Raman, UV/VIS/ligand field, NMR, mass) methods. The ligand L− is in its thione form and behaves as a bidentate chelate with the deprotonated (hydroxyl) oxygen and the nitrogen of one amino gro... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=2467849 Wed, 10 Jun 2009 02:31:38 +0100 2467849 http://www.medworm.com/index.php?rid=2467848&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2009%2F542979.html Organotin(IV) complexes with o- or p-hydroxybenzoic acids (o-H2BZA or p-H2BZA) of formulae [R2Sn(HL)2] (where H2L = o-H2BZA and R = Me- (1), n-Bu- (2)); [R3Sn(HL)] (where H2L = o-H2BZA and R = n-Bu- (3), Ph- (4) or H2L = p-H2BZA and R = n-Bu- (5), Ph- (6)) were synthesized by reacting a methanolic solution of di- and triorganotin(IV) compounds with an aqueous solution of the ligand (o-H2BZA or p-H2BZA) containing equimolar amounts of potassium hydroxide. The complexes were characterized by elemental analysis, FT-IR, Far-IR, TGA-DTA, FT-Raman, Mössbauer spectroscopy, H1, S119n-NMR, UV/Vis spectroscopy, and Mass spectroscopy. The X-ray crystal structures of complexes 1 and 2 have also been determined. Finally, the influence of these complexes 1–6 upon the catalytic peroxidation of... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=2467848 Wed, 10 Jun 2009 02:31:38 +0100 2467848 http://www.medworm.com/index.php?rid=2467847&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2009%2F851316.html A series of metal complexes of Zn(II) and Hg(II) having the general composition [M(L)2]X2 [where L = 2-formylpyridine thiosemicarbazone; M = Zn(II) and Hg(II); X = Cl−, NO3   − and 1/2SO4   2−] have been prepared and characterized by elemental chemical analysis, molar conductance, and spectral (IR and mass) studies. The IR spectral data suggests the involvement of sulphur and azomethane nitrogen in coordination to the central metal ion. On the basis of spectral studies, a tetrahedral geometry has been assigned for Zn(II) and Hg(II) complexes. The free ligand and its metal complexes have been tested in vitro against a number of microorganisms in order to assess their antimicrobial properties. (Source: Bioinorganic Chemistry and ... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=2467847 Wed, 10 Jun 2009 02:31:38 +0100 2467847 http://www.medworm.com/index.php?rid=2467846&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fbca%2F2009%2F908625.html Five new organogermanium sesquioxides have been synthesized and characterized by elemental analysis and IR spectra. All the compounds were tested for antitumor activities against KB, HCT, and Bel cells in vitro. Compound 5 (γ-thiocarbamido propyl germanium sesquioxide) showed excellent antitumor activity, and its inhibition yield to KB, HCT, and Bel cells was 92.9%, 84.9%, and 70.9%, respectively. A rapid method was described for the labeling compound 5 with T99mc, and the optimum labeling conditions were investigated. The labeling yield is above 90% in pH 7.0, 20∘C, reaction time greater than 10 minutes, 1 mg of compound 5, and 0.075∼0.1 mg of SnCl2. The biodistribution of T99mc labeled compound 5 in nude mice bearing human colonic xenogr... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=2467846 Wed, 10 Jun 2009 02:31:38 +0100 2467846 http://www.medworm.com/index.php?rid=2379972&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2009%2F851316 A series of metal complexes of Zn(II) and Hg(II) having the general composition [M(L)2]X2 [where L = 2-formylpyridine thiosemicarbazone; M = Zn(II) and Hg(II); X = Cl−, NO3   − and 1/2SO4   2−] have been prepared and characterized by elemental chemical analysis, molar conductance, and spectral (IR and mass) studies. The IR spectral data suggests the involvement of sulphur and azomethane nitrogen in coordination to the central metal ion. On the basis of spectral studies, a tetrahedral geometry has been assigned for Zn(II) and Hg(II) complexes. The free ligand and its metal complexes have been tested in vitro against a number of microorganisms in order to assess their antimicrobial properties. (Source: Bioinorganic Chemistry and ... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=2379972 Thu, 30 Apr 2009 18:56:51 +0100 2379972 http://www.medworm.com/index.php?rid=2339889&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2009%2F542979 Organotin(IV) complexes with o- or p-hydroxybenzoic acids (o-H2BZA or p-H2BZA) of formulae [R2Sn(HL)2] (where H2L = o-H2BZA and R = Me- (1), n-Bu- (2)); [R3Sn(HL)] (where H2L = o-H2BZA and R = n-Bu- (3), Ph- (4) or H2L = p-H2BZA and R = n-Bu- (5), Ph- (6)) were synthesized by reacting a methanolic solution of di- and triorganotin(IV) compounds with an aqueous solution of the ligand (o-H2BZA or p-H2BZA) containing equimolar amounts of potassium hydroxide. The complexes were characterized by elemental analysis, FT-IR, Far-IR, TGA-DTA, FT-Raman, Mössbauer spectroscopy, H1, S119n-NMR, UV/Vis spectroscopy, and Mass spectroscopy. The X-ray crystal structures of complexes 1 and 2 have also been determined. Finally, the influence of these complexes 1–6 upon the catalytic peroxidation of... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=2339889 Sat, 18 Apr 2009 18:02:52 +0100 2339889 http://www.medworm.com/index.php?rid=2295735&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2008%2F647873 The new complexes [M2O5L2(H2O)2]⋅H2O (M=Mo,1;M=W,2), [RuL2(H2O)2]⋅H2O  (3), [ML3]⋅xH2O (M=Rh,x=2,4;M=Ir,x=1,5), [RhL2(PPh3)2](ClO4)⋅2H2O  (6), [PdL2]⋅2H2O  (7), [PdL(phen)]Cl⋅H2O  (8), [Re⁡OL2(PPh3)]Cl  (9) and [UO2L2]  (10) are reported, where LH is 4,6-diamino-1-hydro-5-hydroxy-pyrimidine-2-thione. The complexes were characterized by elemental analyses, physical techniques (molar conductivity, room-temperature magnetic susceptibility), and spectroscopic (IR, Raman, UV/VIS/ligand field, NMR, mass) methods. The ligand L− is in its thione form and behaves as a bidentate chelate with the deprotonated (hydroxyl) oxygen and the nitrogen of one amino gro... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=2295735 Sun, 29 Mar 2009 03:02:08 +0100 2295735 http://www.medworm.com/index.php?rid=2157450&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2008%2F212461 The interactions between chromium(III) and 3,4-dihydroxybenzoic acid (3,4-DHBA) were studied resulting in the formation of oxygen-bonded complexes upon substitution of water molecules in the chromium(III) coordination sphere. The experimental results show that the reaction takes place in at least three stages, involving various intermediates. The first stage was found to be linearly dependent on ligand concentration k1(obs)_=k0+k1(obs)[3,4-DHBA], and the corresponding activation parameters were calculated as follows: ΔH1(obs)≠=51.2±11.5 kJ mol−1, ΔS1(obs)≠=−97.3±28.9 J mol−1 K−1 (composite activation parameters) . The second and third stages, which are kinetically indistinguishable... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=2157450 Wed, 04 Feb 2009 13:58:43 +0100 2157450 http://www.medworm.com/index.php?rid=2153358&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2008%2F547915 In this report, we present the complexation reactions of 3-ethoxycarbonyl tetronic acids with acetates and chlorides of Cu(II) and Co(II). These complexes have been studied by means of EPR spectroscopy and magnetic susceptibility measurements. From the obtained results, a preliminary complexation mode of the ligand is proposed. (Source: Bioinorganic Chemistry and Applications) Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=2153358 Tue, 03 Feb 2009 13:20:02 +0100 2153358 http://www.medworm.com/index.php?rid=2142071&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2008%2F690952 The palladium(II) bis-chelate Pd (L1−3)2 and platinum (II) tetranuclear Pt4(L4)4 complexes of benzaldehyde thiosemicarbazone derivatives have been synthesized, and characterized by elemental analysis and IR, FAB(+)-mass and NMR (1H,13C) spectroscopy. The complex Pd(L2)2 [HL2=m-CN-benzaldehyde thiosemicarbazone] shows a square-planar geometry with two deprotonated ligands (L) coordinated to PdII through the nitrogen and sulphur atoms in a trans arrangement, while the complex Pt4(L4)4 [HL4=4-phenyl-1-benzaldehyde thiosemicarbazone] has a tetranuclear geometry with four tridentate ligands coordinated to four PtII ions through the carbon (aromatic ring), nitrogen, and sulphur atoms where the ligands are deprotonated at the NH group. The in vitro antitumor activity of the ligands and the... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=2142071 Thu, 29 Jan 2009 16:21:58 +0100 2142071 http://www.medworm.com/index.php?rid=2132714&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2008%2F501021 (6-(cyclohexylamino)-1,3-dimethyl-5(2-pyridyl)furo[2,3-d]pyrimidine-2,4(1H,3H)-dione) abbreviated as CDP was synthesized and characterized. Ti(IV), Zn(II), Fe(III), and Pd(II) metal complexes of this ligand are prepared by the reaction of salts of Ti(IV), Zn(II), Fe(III), and Pd(II) with CDP in acetonitrile. Characterization of the ligand and its complexes was made by microanalyses, FT-IR, 1H NMR, 13C NMR, and UV-Visible spectroscopy. All complexes were characterized by several techniques using elemental analysis (C, H, N), FT-IR, electronic spectra, and molar conductance measurements. The elemental analysis data suggest the stoichiometry to be 1:1 [M:L] ratio formation. The molar conductance measurements reveal the presence of 1:1 electrolytic nature complexes. These new complexes showed ... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=2132714 Mon, 26 Jan 2009 12:11:39 +0100 2132714 http://www.medworm.com/index.php?rid=2087656&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2008%2F690952 The palladium (II) bis-chelate Pd (L1−3)2 and platinum (II) tetranuclear Pt4(L4)4 complexes of benzaldehyde thiosemicarbazone derivatives have been synthesized, and characterized by elemental analysis and IR, FAB(+)-mass and NMR (1H,13C) spectroscopy. The complex Pd(L2)2 [HL2=m-CN-benzaldehyde thiosemicarbazone] shows a square-planar geometry with two deprotonated ligands (L) coordinated to PdII through the nitrogen and sulphur atoms in a transarrangement, while the complex Pt4(L4)4 [HL4=4-phenyl-1-benzaldehyde thiosemicarbazone] has a tetranuclear geometry with four tridentate ligands coordinated to four PtII ions through the carbon (aromatic ring), nitrogen, and sulphur atoms where the ligands are deprotonated at the NH group. The in vitro antitumor activity of the ligands and the... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=2087656 Thu, 08 Jan 2009 12:24:21 +0100 2087656 http://www.medworm.com/index.php?rid=1999622&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2008%2F706240 In order to investigate the behavior of rare earth elements (REEs) and uranium (U) in marine organism, the concentrations of REEs and U in some brown algae samples taken on the coast of Niigata Prefecture were determined. In addition, laboratory model experiment to uptake these elements using living and dried algae (Undaria pinnatifida and Sargassum hemiphyllum) was also carried out to survey the uptake and bioaccumulation mechanism of REEs and U in algae. Consequently, the following matters have been mainly clarified. (1) The order of the concentration of REEs for each organ in Sargassum hemiphyllum is “main branch” > “leaf” > “vesicle,” however for U, the order is “leaf” > “vesicle” > “main branch.” (... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=1999622 Mon, 01 Dec 2008 12:53:56 +0100 1999622 http://www.medworm.com/index.php?rid=1992560&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2008%2F436458 Formation of silver citrate/citric acid complexed solutions was investigated. Although, silver citrate is minimally soluble in water, it can successfully be dissolved in citric acid solutions. The maximum concentration of Ag(I) in solution is estimated at 23 to 25 g/L if the concentration of citric acid is at least 4 mol/L or higher. The dissolution of silver citrate in citric acid solutions was attributed to the formation of silver citrate complexes of a general formula [Ag3(C6H5O7)n+1]3n−. The silver citrate/citric acid solutions, containing more than about 13 g/L Ag+ ion, have exhibited a decrease in Ag(I) concentration in solution over time, due to crystallization. The crystallization product was attributed to the formation of [Ag3C6H5O7]x⋅nH2O. Impor... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=1992560 Thu, 27 Nov 2008 15:12:26 +0100 1992560 http://www.medworm.com/index.php?rid=1816411&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2008%2F762029 The biomimetic catalytic oxidations of the dinuclear and trinuclear copper(II) complexes versus two catechols, namely, D-(+)-catechin and L-(−)-epicatechin to give the corresponding quinones are reported. The unstable quinones were trapped by the nucleophilic reagent, 3-methyl-2-benzothiazolinone hydrazone (MBTH), and have been calculated the molar absorptivities of the different quinones. The catalytic efficiency is moderate, as inferred by kinetic constants, but the complexes exhibit significant enantio-differentiating ability towards the catechols, albeit for the dinuclear complexes, this enantio-differentiating ability is lower. In all cases, the preferred enantiomeric substrate is D-(+)-catechin to respect the other catechol, because of the spatial disposition of this s... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=1816411 Tue, 23 Sep 2008 18:24:54 +0100 1816411 http://www.medworm.com/index.php?rid=1665290&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2008%2F253971 Interactions between aspartic acid (Asp) and cytidine-5-monophosphate (CMP) in metal-free systems as well as the coordination of Cu(II) ions with the above ligands were studied. The composition and overall stability constants of the species formed in those systems were determined by the potentiometric method, and the interaction centres in the ligands were identified by the spectral methods UV-Vis, EPR, NMR, and IR. In metal-free systems, the formation of adducts, in which each ligand has both positive and negative reaction centres, was established. The main reaction centres in Asp are the oxygen atoms of carboxyl groups and the nitrogen atom of the amine group, while the main reaction centre in CMP at low pH is the N(3) atom. With increasing pH, the efficiency of the phosphate group of th... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=1665290 Wed, 30 Jul 2008 15:22:45 +0100 1665290 http://www.medworm.com/index.php?rid=1658348&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2008%2F624583 Our study of the complexation of 3,4-dihydroxy-phenyl-propenoic acid by chromium(III) could give information on the way that this metal ion is available to plants. The reaction between chromium(III) and 3,4-dihydroxy-phenyl-propenoic acid in weak acidic aqueous solutions has been shown to take place by at least three stages. The first stage corresponds to substitution (Id mechanism) of water molecule from the Cr(H2O)5OH2+ coordination sphere by a ligand molecule. A very rapid protonation equilibrium, which follows, favors the aqua species. The second and the third stages are chromium(III) and ligand concentration independent and are attributed to isomerisation and chelation processes. The corresponding activation parameters are ΔH2(obs)≠ = 28.6 ± 2.9 kJ mol&#x22... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=1658348 Mon, 28 Jul 2008 12:56:23 +0100 1658348 http://www.medworm.com/index.php?rid=1492735&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2008%2F576297 Class B β-lactamases or metallo-β-lactamases (MBLs) require zinc ions to catalyse the hydrolysis of β-lactam antibiotics such as penicillins, cephalosporins, carbapenems, and cephamycins. There are no clinically useful inhibitors against MBLs which are responsible for the resistance of some bacteria to antibiotics. There are two metal-ion binding sites that have different zinc ligands but the exact roles of the metal-ion remain controversial, and distinguishing between their relative importance is complex. The metal-ion can act as a Lewis acid by co-ordination to the β-lactam carbonyl oxygen to facilitate nucleophilic attack and stabilise the negative charge developed on this oxygen in the tetrahedral intermediate anion. The metal-ion also lowers the pKa of the ... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=1492735 Wed, 04 Jun 2008 17:45:00 +0100 1492735 http://www.medworm.com/index.php?rid=1489874&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2007%2F92595 The progress of the research work of the author and his colleagues on the field of CL-emission generated by pyrogallol oxidation and further application for the direct determination of periodate and indirect or direct determination of other compounds through flow-injection manifold/CL-detection set up is described. The instrumentation used for these studies was a simple flow-injection manifold that provides good reproducibility, coupled to a red sensitive photomultiplier that gives sensitive CL-detection. In addition, recent reports on studies and analytical methods based on CL-emission generated by periodate oxidation by other authors are included. (Source: Bioinorganic Chemistry and Applications) Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=1489874 Tue, 03 Jun 2008 22:25:23 +0100 1489874 http://www.medworm.com/index.php?rid=1489873&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2007%2F69263 A novel method for the preparation of hitherto unknown symmetrical bis(2-halo-3-pyridyl) dichalcogenides (E = S, Se and Te) by the oxidation of intermediate 2-halo-3-pyridyl chalcogenolate, prepared by lithiation of 2-halo pyridines using lithium diisopropylamine is being reported. All the newly synthesized compounds have been characterized through elemental analysis employing various spectroscopic techniques, namely, NMR (H1, C13, S77e), infrared, mass spectrometry, and X-ray crystal structures in representative cases. (Source: Bioinorganic Chemistry and Applications) Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=1489873 Tue, 03 Jun 2008 22:25:23 +0100 1489873 http://www.medworm.com/index.php?rid=1489872&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2007%2F65815 This review discusses in detail “calixarenes” since their discovery as by-products of the phenol formaldehyde bakelites till the present scenario wherein calixarene has assumed a new dimension in the field of supramolecular chemistry. Extensive literature exists for calixarenes; but herein we have tried to concentrate on the different lower-rim modified calixarenes with their potential applications. An attempt has also been made to critically evaluate the synthesis procedures for different lower-rim substituted calixarenes. (Source: Bioinorganic Chemistry and Applications) Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=1489872 Tue, 03 Jun 2008 22:25:23 +0100 1489872 http://www.medworm.com/index.php?rid=1489871&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2007%2F17416 The 3 centre-4 electrons (3c-4e) and the donor/acceptor or charge-transfer models for the description of the chemical bond in linear three-body systems, such as I3− and related electron-rich (22 shell electrons) systems, are comparatively discussed on the grounds of structural data from a search of the Cambridge Structural Database (CSD). Both models account for a total bond order of 1 in these systems, and while the former fits better symmetric systems, the latter describes better strongly asymmetric situations. The 3c-4e MO scheme shows that any linear system formed by three aligned closed-shell species (24 shell electrons overall) has reason to exist provided that two electrons are removed from it to afford a 22 shell electrons three-body system: all combinations o... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=1489871 Tue, 03 Jun 2008 22:25:23 +0100 1489871 http://www.medworm.com/index.php?rid=1489870&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2007%2F23286 This paper is a brief review of the detailed mechanism of action of thiamine enzymes, based on metal complexes of bivalent transition and post-transition metals of model compounds, thiamine derivatives, synthesized and characterized with spectroscopic techniques and X-ray crystal structure determinations. It is proposed that the enzymatic reaction is initiated with a V conformation of thiamine pyrophosphate, imposed by the enzymic environment. Thiamine pyrophosphate is linked with the proteinic substrate through its pyrophosphate oxygens. In the course of the reaction, the formation of the “active aldehyde” intermediate imposes the S conformation to thiamine, while a bivalent metal ion may be linked through the N1' site of the molecule, at this stage. Finally, the immobiliz... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=1489870 Tue, 03 Jun 2008 22:25:23 +0100 1489870 http://www.medworm.com/index.php?rid=1489869&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2007%2F46393 Trends in the properties of normal valent and multivalent halogen-oxygen bonding are examined for the isomers of the halogen polyoxide families of the types (YXO2) and (YXO3), Y=Cl, Br, I, H, CH3, X=Cl, Br, I. A qualitative model is formulated on the relationship between the X-O bond distance variations, the ionic character of the bonding, and the degree of halogen valence. The relative stability and enthalpy of formation of each species are also suggested to correlate with the ionic nature of the X-O bonding and the electrostatic character of the Y, YO fragments. In the model presented, halogen hypervalence is interpreted to be the result of partial p→d promotion of lone-pair valence electrons followed by the formation of two, four, or six additional pd hybrid bonds around the halo... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=1489869 Tue, 03 Jun 2008 22:25:23 +0100 1489869 http://www.medworm.com/index.php?rid=1489868&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2007%2F87918 The reactions of (η5−C5H5)2MCl2 (M = Ti, Zr, or Hf) with mercaptoazoles (LH2), namely, bis(mercaptotriazoles), bis(mercap-tooxadiazoles), and bis(mercaptothiadiazoles) in 2 : 1 molar ratio, respectively, have been studied in dry tetrahydrofuran in the presence of n-butylamine and the binuclear complexes of the type [{(η−C5H5)2M}2(L)] (M = Ti/Zr/Hf) are obtained. Tentative structural conclusions are drawn for the reaction products based upon elemental analysis, electrical conductance, magnetic moment, and spectral data (UV-Vis, IR, H1 NMR, and C13 NMR). FAB-mass spectra of few complexes of each series were also carried out to confirm the binuclear structures. Studies were conducted to assess the growth-inhibiting potential of the complexes synthesiz... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=1489868 Tue, 03 Jun 2008 22:25:23 +0100 1489868 http://www.medworm.com/index.php?rid=1489867&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2007%2F54562 In this paper, three complexes of type [Co(en)2PIP]3+(PIP=2-phenylimidazo[4,5-f][1,10,] phenanthroline)(1), [Co(en)2IP]3+ (IP=imidazo[4,5-f][1,10,] phenanthroline)(2), and [Co(en)2phen-dione]3+(1,10 phenanthroline 5,6,dione)(3) have been synthesized and characterized by UV/VIS, IR, 1H NMR spectral methods. Absorption spectroscopy, emission spectroscopy, viscosity measurements, and DNA melting techniques have been used for investigating the binding of these two complexes with calf thymus DNA, and photocleavage studies were used for investigating these binding of these complexes with plasmid DNA. The spectroscopic studies together with viscosity measurements and DNA melting studies support that complexes 1 and 2 bind to CT DNA(=calf thymus DNA) by intercalation mode via IP or PIP into the ba... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=1489867 Tue, 03 Jun 2008 22:25:23 +0100 1489867 http://www.medworm.com/index.php?rid=1489866&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2007%2F28508 Reactions of 2,2'-pyridil (pyCOCOpy) with CuCl2⋅2H2O and CuBr2 in EtOH yielded the mononuclear complex [Cu(pyCOOEt)2Cl2]⋅H2O (1) and the one-dimensional, mixed-valence complex [Cu2ICuII(pyCOOEt)2Br4]n (2), respectively. Both complexes crystallize in the triclinic space group P 1¯. The lattice constants are a=8.382(2), b=9.778(2), c=7.814(2), α=101.17(1), β=114.55(1), γ=94.14(1)∘ for 1 and a=8.738(1), b=9.375(2), c=7.966(1), α=79.09(1), β=64.25(1), γ=81.78(1)∘ for 2. 2,2'-pyridil undergoes a metal-assisted alcoholysis and oxidation leading to decomposition and yielding the ethyl picolinate (pyCOOEt) ligand. The autoredox process associated with the reduction of copper(II) to copper(I) in the case of c... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=1489866 Tue, 03 Jun 2008 22:25:23 +0100 1489866 http://www.medworm.com/index.php?rid=1489865&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2007%2F92145 A number of trimethylsiloxyalkyl and trialkylsilylalkyl thiazole derivatives have been evaluated for their anti-inflammatory activity, lipoxygenase inhibiting properties, and cytotoxicity. The investigated compounds have been found to protect in vivo against carrageenin-induced edema, especially 3-(4-trimethylsiloxypiperidin-1-yl)-N-(thiazol-2-yl)-propionamide (21) and 2-amino-3-(γ-trimethylsilylpropyl)thiazolium iodide (22), which exhibited good anti-inflammatory activity: 57.2% CPE inhibition in dose of 0.2 mmol/kg for compound 21 and 55.0% in dose of 0.01 mmol/kg for compound 22. All the compounds tested inhibited soybean lipoxygenase activity. 2-(4-Trimethylsilyloxypiperidin-1-yl)-N-[4-(p-methoxyphenyl)-thiazol-2-yl]-acetamide (19) was the most potent... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=1489865 Tue, 03 Jun 2008 22:25:23 +0100 1489865 http://www.medworm.com/index.php?rid=1489864&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2007%2F98732 Four new metal complexes {M = Pd(II) or Pt(II)} containing the ligand 9-aminoacridine (9AA) were prepared. The compounds were characterized by FT-IR and H1, C13, and P195t NMR spectroscopies. Crystal structure of the palladium complex of formulae [Pd(9AA)(μ-Cl)]2·2DMF was determined by X-ray diffraction. Two 9-acridine molecules in the imine form bind symmetrically to the metal ions in a bidentate fashion through the imine nitrogen atom and the C(1) atom of the aminoacridine closing a new five-membered ring. By reaction with phosphine or pyridine, the Cl bridges broke and compounds with general formulae [Pd(9AA)Cl(L)] (where L=PPh3 or py) were formed. A mononuclear complex of platinum of formulae [Pt(9AA)Cl(DMSO)] was also obtained by direct reaction... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=1489864 Tue, 03 Jun 2008 22:25:23 +0100 1489864 http://www.medworm.com/index.php?rid=1489863&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2007%2F54232 The unfolding process of the blue copper protein rusticyanin has been studied from the structural and the thermodynamic points of view at two pH values (pH 2.5 and 7.0). When Rc unfolds, copper ion remains bound to the polypeptide chain. Nuclear magnetic resonance data suggest that three of the copper ligands in the folded state are bound to the metal ion in the unfolded form, while the other native ligand is detached. These structural changes are reflected in the redox potentials of the protein in both folded and unfolded forms. The affinities of the copper ion in both redox states have been also determined at the two specified pH values. The results indicate that the presence of two histidine ligands in the folded protein can compensate the change in the net charge that the copper ion re... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=1489863 Tue, 03 Jun 2008 22:25:23 +0100 1489863 http://www.medworm.com/index.php?rid=1489862&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2007%2F43424 Two copper(II)-ACC complexes were prepared and characterized: [Cu(bpy)(ACC)(H2O)]⋅CO4 (1) and [Cu(ACC)2]3⋅4H2O (2). Their crystallographic structures are described and analyzed. Spectroscopic characterizations (UV-visible and EPR) confirm that the structure is maintained in solution. These complexes are able to produce ethylene in the presence of hydrogen peroxide in an “ACC Oxidase-like” reaction in water and in methanol. The conversion of ACC into ethylene depends on the amount of base, and, in methanol, 3 equivalents of NaOH are needed for optimum activity. The base is proposed to play a role in H2O2 deprotonation. The presence of an exogenic ligand (bpy) is important for the reactivity and may stabilize a reaction intermediate. Indeed, a brown intermediate w... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=1489862 Tue, 03 Jun 2008 22:25:23 +0100 1489862 http://www.medworm.com/index.php?rid=1489861&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2007%2F42587 The synthesis and characterization of title complexes of the ligand Quinolino[3,2-b]benzodiazepine (QBD) and Quinolino[3,2-b]benzoxazepine (QBO) are reported. The complexes have been characterized by elemental analysis, molar conductance, magnetic studies, IR, H1 NMR, and UV-visible studies. They have the stoichiometry [ML2C12], where M=Co(II)/Ni(II), L=QBD/QBO, and [MLC12], where M=Zn(II)/Cd(II), L=QBD/QBO. The antibacterial and antifungal activity of the metal complexes has been investigated. The complexes were found to have higher antimicrobial activity than the parent ligand. (Source: Bioinorganic Chemistry and Applications) Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=1489861 Tue, 03 Jun 2008 22:25:23 +0100 1489861 http://www.medworm.com/index.php?rid=1489860&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2007%2F91078 The interaction of drugs with DNA is an important aspect in pharmacology. In recent years, many important technological advances have been made to develop new techniques to monitor biorecognition and biointeraction on solid devices. The interaction between DNA and drugs can cause chemical and conformational modifications and, thus, variation of the electrochemical properties of nucleobases. The propensity of a given compound to interact with DNA is measured as a function of the decrease of guanine oxidation signal on a DNA electrochemical biosensor. Covalent binding at N7 of guanine, electrostatic interactions, and intercalation are the events that this kind of biosensor can detect. In this context, the interaction between a panel of antitumoral Pt-, Ru-, and Ti-based metallodrugs with DNA... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=1489860 Tue, 03 Jun 2008 22:25:23 +0100 1489860 http://www.medworm.com/index.php?rid=1489859&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2007%2F51483 A series of metal complexes of Cu(II) and Ni(II) having the general composition [M(L)X2] with benzil bis(thiosemicarbazone) has been prepared and characterized by element chemical analysis, molar conductance, magnetic susceptibility measurements, and spectral (electronic, IR, EPR, mass) studies. The IR spectral data suggest the involvement of sulphur and azomethane nitrogen in coordination to the central metal ion. On the basis of spectral studies, an octahedral geometry has been assigned for Ni(II) complexes but a tetragonal geometry for Cu(II) complexes. The free ligand and its metal complexes have been tested in vitro against a number of microorganisms in order to assess their antimicrobial properties. (Source: Bioinorganic Chemistry and Applications) Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=1489859 Tue, 03 Jun 2008 22:25:23 +0100 1489859 http://www.medworm.com/index.php?rid=1489858&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2007%2F10720 The 173–195 segment corresponding to the helix 2 of the C-globular prion protein domain could be one of several “spots” of intrinsic conformational flexibility. In fact, it possesses chameleon conformational behaviour and gathers several disease-associated point mutations. We have performed spectroscopic studies on the wild-type fragment 173–195 and on its D178N mutant dissolved in trifluoroethanol to mimic the in vivo system, both in the presence and in the absence of metal cations. NMR data showed that the structure of the D178N mutant is characterized by two short helices separated by a kink, whereas the wild-type peptide is fully helical. Both peptides retained these structural organizations, as monitored by CD, in the presence of metal cations. NMR spectra were... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=1489858 Tue, 03 Jun 2008 22:25:23 +0100 1489858 http://www.medworm.com/index.php?rid=1489857&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2007%2F30394 Terminally protected pentapeptides with 2 histidines (Ac-HHVGD-NH2 and Ac-HVGDH-NH2) and the terminally free peptides containing both internal aspartyl and C-terminal histidyl residues (FDAH and VIDAH) have been synthesized, and copper(II) complexes studied by potentiometric, UV-Vis, CD, and EPR spectroscopic techniques in solution. Both thermodynamic and spectroscopic data reveal that side chain donor atoms of aspartyl and histidyl residues have a significant contribution to the metal binding affinity of peptide molecules. In the case of terminally protected peptides, the role of the imidazole-N donor functions is reflected in the enhanced stability of the 3N and 4N coordinated copper(II) complexes. The amino and β-carboxylate groups of FDAH and VIDAH create a very effec... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=1489857 Tue, 03 Jun 2008 22:25:23 +0100 1489857 http://www.medworm.com/index.php?rid=1489856&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2007%2F53521 Interactions between sinefungin and copper(II) ions were investigated. Stoichiometry and stability constants of the metal-free system and two mononuclear complexes present in solution were determined on the basis of potentiometric data analysis. The results were compared to the Cu(II)-ornithine system due to structural similarities between both molecules. Combined spectroscopic and theoretical studies allowed for determination of coordination pattern for the Cu(II)-sinefungin complexes. At acidic pH, copper is bound in “glycine-like” coordination mode, identical with that of ornithine. This involves α-amino group and the carboxyl oxygen. At higher pH, a “bis-complex” is formed by two sinefungin molecules. The second ligand binds in equatorial position d... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=1489856 Tue, 03 Jun 2008 22:25:23 +0100 1489856 http://www.medworm.com/index.php?rid=1489855&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2007%2F96536 Solution equilibrium studies on Fe(III) complexes formed with imidazole-4-carbohydroxamic acid (Im-4-Cha), N-Me-imidazole-4-carbohydroxamic acid (N-Me-Im-4-Cha), imidazole-4-acetohydroxamic acid (Im-4-Aha), and histidinehydroxamic acid (Hisha) have been performed by using pH-potentiometry, UV-visible spectrophotometry, EPR, ESI-MS, and H1-NMR methods. All of the obtained results demonstrate that the imidazole moiety is able to play an important role very often in the interaction with Fe(III), even if this metal ion prefers the hydroxamate chelates very much. If the imidazole moiety is in α-position to the hydroxamic one (Im-4-Cha and N-Me-Im-4-Cha) its coordination to the metal ion is indicated unambiguously by our results. Interestingly, parallel formation of (Nimidazole, Ohydrox... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=1489855 Tue, 03 Jun 2008 22:25:23 +0100 1489855 http://www.medworm.com/index.php?rid=1489854&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2007%2F51567 The 12 : 1 reaction of urea (U) with CoI2 in EtOH yielded the “clathrate-coordination” compound [CoU6]I2·4U (1). The complex crystallizes in the monoclinic space group P21/c. The lattice constants are a = 9.844(4), b = 7.268(3), c = 24.12(1) Å, and β=98.12(1)∘. The crystal structure determination demonstrates the existence of octahedral [CoU6]2+ cations, I- counterions, and two different types (two U1 and two U2) of hydrogen-bonded, lattice urea molecules. The [CoU6]2+ cations and the U1 lattice molecules form two-dimensional hydrogen-bonded layers which are parallel to the ab plane. The I- anions are placed above and below each layer, and are hydrogen bonded both to U1 molecules and [CoU6]2+ cations. Each U2 molecule is connected to a [CoU6]2+ catio... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=1489854 Tue, 03 Jun 2008 22:25:23 +0100 1489854 http://www.medworm.com/index.php?rid=1489853&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2008%2F479897 A new series of Zn2+, Cu2+, Ni2+, and Co2+ complexes of N1-methyl-2-(1H-1,2,3-benzotriazol-1-yl)-3-oxobutanethioamide (MBOBT), HL, has been synthesized and characterized by different spectral and magnetic measurements and elemental analysis. IR spectral data indicates that (MBOBT) exists only in the thione form in the solid state while 13C NMR spectrum indicates its existence in thione and thiole tautomeric forms. The IR spectra of all complexes indicate that (MBOBT) acts as a monobasic bidentate ligand coordinating to the metal(II) ions via the keto-oxygen and thiolato-sulphur atoms. The electronic spectral studies showed that (MBOBT) bonded to all metal ions through sulphur and nitrogen atoms based on the positions and intensity of their charge transfer bands. Furthermore, the spectra... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=1489853 Tue, 03 Jun 2008 22:25:23 +0100 1489853 http://www.medworm.com/index.php?rid=1489852&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2008%2F294756 The formation of the DNA G-quadruplex is induced by the addition of a novel porphyrin carrying four cationic tethers. Circular dichroism spectroscopy reveals that the porphyrin binds to Tetrahymena telomeric repeat to form G-quadruplex under stabilizing-cation-deficient and no buffer conditions. (Source: Bioinorganic Chemistry and Applications) Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=1489852 Tue, 03 Jun 2008 22:25:23 +0100 1489852 http://www.medworm.com/index.php?rid=1489851&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2008%2F654137 A novel tri-n-butyl(IV) derivative of 2-thiobarbituric acid (HTBA) of formula [(n-Bu)3Sn(TBA)⋅H2O] (1) has been synthesized and characterized by elemental analysis and 119Sn-NMR and FT-IR spectroscopic techniques. The crystal structure of complex 1 has been determined by single crystal X-ray diffraction analysis at 120(2) K. The geometry around Sn(IV) is trigonal bipyramidal. Three n-butyl groups and one oxygen atom from a deprotonated 2-thiobarbituric ligand are bonded to the metal center. The geometry is completed with one oxygen from a water molecule. Compound 1 exhibits potent, in vitro, cytotoxicity against sarcoma cancer cells (mesenchymal tissue) from the Wistar rat, polycyclic aromatic hydrocarbons (PAH, benzo[a]pyrene) carcinogenesis. In addition, the inhi... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=1489851 Tue, 03 Jun 2008 22:25:23 +0100 1489851 http://www.medworm.com/index.php?rid=1489850&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2008%2F257038 The N- and C-terminal blocked hexapeptide Ac-Leu-Ala-His-Tyr-Asn-Lys-amide (LAHYNK) representing the 80–85 fragment of histone H2B was synthesized and its interactions with Cu(II) and Ni(II) ions were studied by potentiometric, UV-Vis, CD, EPR, and NMR spectroscopic techniques in solution. Our data reveal that the imidazole N(3) nitrogen atom is the primary ligating group for both metal ions. Sequential amide groups deprotonation and subsequent coordination to metal ions indicated an {Nimidazole,3Namide} coordination mode above pH∼9, in all cases. In the case of Cu(II)-peptide system, the almost exclusive formation of the predominant species CuL in neutral media accounting for almost 98% of the total metal ion concentration at pH 7.3 strongly indicates that at physiologica... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=1489850 Tue, 03 Jun 2008 22:25:23 +0100 1489850 http://www.medworm.com/index.php?rid=1489849&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2008%2F420578 In this study we analyzed blood and urine samples from shipyard industry welders being exposed to different levels of Cr(VI) over a period of five months in order to assay in vivo the relation of ApoJ/CLU serum levels with Cr(VI). Our findings confirmed the previously reported in vitro data since reduction of Cr levels, after a worksite intervention, associated with lower levels of ApoJ/CLU serum levels. We concluded that the human ApoJ/CLU gene is responsive to the acute in vivo oxidative stress induced by heavy metals such as hexavalent chromium. (Source: Bioinorganic Chemistry and Applications) Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=1489849 Tue, 03 Jun 2008 22:25:23 +0100 1489849 http://www.medworm.com/index.php?rid=1489848&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2008%2F469062 Molecular dynamics simulation of the interaction between the Tenebrio molitor alpha-amylase and its inhibitor at different proportion of crystal water was carried out with OPLS force field by hyperchem 7.5 software. In the correlative study, the optimal temperature of wheat monomeric and dimeric protein inhibitors was from 273 K to 318 K. The the average temperature of experimentation is 289 K. (1) The optimal temperature of interaction between alpha-amylase and its inhibitors was 280 K without crystal water that was close to the results of experimentation. The forming of enzyme-water and inhibitor-water was easy, but incorporating third monomer was impossible. (2) Having analyzed the potential energy data, the optimal temperature of interaction energy between a... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=1489848 Tue, 03 Jun 2008 22:25:23 +0100 1489848 http://www.medworm.com/index.php?rid=1489847&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2008%2F367471 The antineoplastic potential of a stable monomeric Au(II) complex with hematoporphyrin IX (Hp), namely [Au(II)Hp-2H.(H2O)2], was investigated in a panel of tumor cell lines. The complex exhibits strong cytotoxicity, whereby the leukaemia- and lymphoma-derived cell lines are more sensitive, with IC50 values comparable to those of the reference anticancer drug cisplatin. In contrast, the solid tumor models are more sensitive to the platinum drug. A comparative assessment of both agents against the human kidney cell line 293T has shown that [Au(II)Hp-2H.(H2O)2] is less cytotoxic. The gold complex induces oligonucleosomal DNA fragmentation in tumour cells following 24-hour treatment and hence its cytotoxic effect is at least partly mediated by induction of apoptotic cell death. A prominent int... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=1489847 Tue, 03 Jun 2008 22:25:23 +0100 1489847 http://www.medworm.com/index.php?rid=1489846&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2008%2F539082 The trivalent arsenic glutathione complexes arsenic triglutathione, methylarsonous diglutathione, and dimethylarsinous glutathione are key intermediates in the mammalian metabolism of arsenite and possibly represent the arsenic species that are transported from the liver to the kidney for urinary excretion. Despite this, the comparative stability of the arsenic-sulfur bonds in these complexes has not been investigated under physiological conditions resembling hepatocyte cytosol. Using size-exclusion chromatography and a glutathione-containing phosphate buffered saline mobile phase (5 or 10 mM glutathione, pH 7.4) in conjunction with an arsenic-specific detector, we chromatographed arsenite, monomethylars... Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=1489846 Tue, 03 Jun 2008 22:25:23 +0100 1489846 http://www.medworm.com/index.php?rid=1489845&cid=s_37044_60_f&fid=37044&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2008%2F983725 A sequence of stages in the syntheses of isomeric bisamino acid complexes of Pt(II) with β-aminopropionic acid (β-alanine = β-AlaH) has been studied by the P195t NMR spectroscopy. The techniques have been developed of the synthesis of the cis- and trans-bischelates of Pt(II) and Pd(II) with β-alanine as well as of the halide complexes of trans-[M(β-AlaH)2Cl2] (M = Pt, Pd) and trans-K2[Pt(β-Ala)2I2] types. The NMR spectroscopy and IR spectroscopy (in the nuclei of P195t,C13,H1) and X-ray diffraction analysis have been used to examine the structures of the synthesized compounds. (Source: Bioinorganic Chemistry and Applications) Bioinorganic Chemistry and Applications journals http://www.medworm.com/rss/comments.php?id=1489845 Tue, 03 Jun 2008 22:25:23 +0100 1489845