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Sodium Formate (sodium + formate)
Selected AbstractsChemInform Abstract: Dehalogenation of Polychloroarenes with Sodium Formate in Propan-2-ol Catalyzed by RhCl(PPh3)3.CHEMINFORM, Issue 37 2001Maria A. Atienza Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Cryoprotection properties of salts of organic acids: a case study for a tetragonal crystal of HEW lysozymeACTA CRYSTALLOGRAPHICA SECTION D, Issue 7 2010Grzegorz Bujacz Currently, the great majority of the data that are used for solving macromolecular structures by X-ray crystallography are collected at cryogenic temperatures. Selection of a suitable cryoprotectant, which ensures crystal stability at low temperatures, is critical for the success of a particular diffraction experiment. The effectiveness of salts of organic acids as potential cryoprotective agents is presented in the following work. Sodium formate, acetate, malonate and citrate were tested, as were sodium potassium tartrate and acetate in the form of potassium and ammonium salts. For each salt investigated, the minimal concentration that was required for successful cryoprotection was determined over the pH range 4.5,9.5. The cryoprotective ability of these organic salts depends upon the number of carboxylic groups; the lowest concentration required for cryoprotection was observed at neutral pH. Case-study experiments conducted using the tetragonal form of hen egg-white lysozyme (HEWL) confirmed that salts of organic acids can successfully act as cryoprotective agents of protein crystals grown from high concentrations of inorganic salts. When crystals are grown from solutions containing a sufficient concentration of organic acid salts no additional cryoprotection is needed as the crystals can safely be frozen directly from the crystallizing buffers. [source] Water-Soluble Arene Ruthenium Complexes Containing a trans -1,2-Diaminocyclohexane Ligand as Enantioselective Transfer Hydrogenation Catalysts in Aqueous SolutionEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 22 2005Jérôme Canivet Abstract The cationic chloro complexes [(arene)Ru(H2N,NH2)Cl]+ (1: arene = C6H6; 2: arene = p -MeC6H4iPr; 3: arene = C6Me6) have been synthesised from the corresponding arene ruthenium dichloride dimers and enantiopure (R,R or S,S) trans -1,2-diaminocyclohexane (H2N,NH2) and isolated as the chloride salts. The compounds are all water-soluble and, in the case of the hexamethylbenzene derivative 3, the aqua complex formed upon hydrolysis [(C6Me6)Ru(H2N,NH2)OH2]2+ (4) could be isolated as the tetrafluoroborate salt. The molecular structures of 3 and 4 have been determined by single-crystal X-ray diffraction analyses of [(C6Me6)Ru(H2N,NH2)Cl]Cl and [(C6Me6)Ru(H2N,NH2)OH2][BF4]2. Treatment of [Ru2(arene)2Cl4] with the monotosylated trans -1,2-diaminocyclohexane derivative (TsHN,NH2) does not yield the expected cationic complexes, analogous to 1,3 but the neutral deprotonated complexes [(arene)Ru(TsN,NH2)Cl] (5: arene = C6H6; 6: arene = p -MeC6H4iPr; 7: arene = C6Me6; 8: arene = C6H5COOMe). Hydrolysis of the chloro complex 7 in aqueous solution gave, upon precipitation of silver chloride, the corresponding monocationic aqua complex [(C6Me6)Ru(TsHN,NH2)(OH2)]+ (9) which was isolated and characterised as its tetrafluoroborate salt. The enantiopure complexes 1,9 have been employed as catalysts for the transfer hydrogenation of acetophenone in aqueous solution using sodium formate and water as a hydrogen source. The best results were obtained (60 °C) with 7, giving a catalytic turnover frequency of 43 h,1 and an enantiomeric excess of 93,%. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) [source] The use of sodium formate for the recovery of precious metals from acidic base metal effluentsJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 4 2001Herman G Julsing Abstract Zinc was used for the reduction of the platinum group metals (PGMs) in acidic effluents. Due to the increasing cost of zinc, sodium formate was investigated as an alternative reductant. In a base metal-containing acidic effluent, called diethylenetriamine barren, sodium formate was used to precipitate the PGMs. This effluent was the filtrate obtained after a precipitation procedure had been used to remove rhodium and iridium. It was found that pH 1.5 was the optimum starting pH for sodium formate reduction. The pH increased to approximately 4.5 after the addition of sodium formate. The optimum concentration of sodium formate was found to be 30,g,dm,3 at a temperature of 100,°C where the process time was 6,h. Platinum and palladium were the most effectively reduced PGMs, both exhibiting an average precipitation efficiency of greater than 99%. Difficulty was experienced with the precipitation of iridium (average precipitation efficiency of 76%). The precipitated PGMs readily dissolved in hydrochloric acid (6,M) and sodium chlorate (2%). A reduction in costs resulted from the discontinuation of the use of zinc for reduction purposes. An additional advantage was that zinc was no longer introduced into the PGM refinery circuits. © 2001 Society of Chemical Industry [source] Crystallization of the 43,kDa ATPase domain of Thermus thermophilus gyrase B in complex with novobiocinACTA CRYSTALLOGRAPHICA SECTION D, Issue 8 2002V. Lamour The 43,kDa ATPase domain of Thermus thermophilus gyrase B was overproduced in Escherichia coli and a three-step purification protocol yielded large quantities of highly purified enzyme which remained stable for weeks. Crystals of the 43,kDa domain in complex with novobiocin, one of the most potent inhibitors of bacterial topoisomerases, were obtained. Crystals obtained in the presence of PEG 8000 do not diffract, but a different crystal form was obtained using sodium formate as a precipitating agent. The plate-shaped crystals, which were less than 10,µm in thickness, could be cryocooled directly from the mother liquor and a full diffraction data set was collected to 2.3,Å allowing the determination of the first structure of a gyrase B 43K domain in complex with a coumarin. [source] Crystallization and preliminary X-ray diffraction studies of catalase,peroxidase from Synechococcus PCC 7942ACTA CRYSTALLOGRAPHICA SECTION D, Issue 1 2002Kei Wada The recombinant catalase,peroxidase of Synechococcus PCC 7942 overexpressed in Escherichia coli was purified and crystallized by the hanging-drop vapour-diffusion method using sodium formate as a precipitant. The crystals belonged to the tetragonal space group P41212 or P43212, with unit-cell parameters a = b = 109.3, c = 202.0,Å. The calculated VM value based on a dimer in the asymmetric unit was 1.9,Å3,Da,1. A native data set was collected to 2.3,Å resolution from a frozen crystal using synchrotron radiation at SPring-8. [source] Purification and crystallization of the human RXR, ligand-binding domain,9- cisRA complexACTA CRYSTALLOGRAPHICA SECTION D, Issue 3 2001Pascal F. Egea The purification and crystallization of the stoichiometric complex of human RXR, ligand-binding domain (hRXR, LBD) bound to its natural ligand 9- cis retinoic acid (9- cisRA) are described. A three-step purification yields a pure and homogenous complex. Based on the crystallization conditions of several other nuclear receptors, an exhaustive crystallization screening using carboxylic acids as precipitating agents was performed in association with the use of polyhydric alcohols acting as cosmotropic solutes. Crystals of the hRXR, LBD,9- cisRA complex grew in a tripartite mixture containing sodium formate, glycerol and propane-1,2-diol. Micro- and macroseeding were necessary to improve both the size and the quality of crystals in order to make them suitable for structure determination. [source] Crystallization and preliminary X-ray diffraction analysis of a [2Fe,2S] ferredoxin (FdVI) from Rhodobacter capsulatusACTA CRYSTALLOGRAPHICA SECTION D, Issue 2 2001Jean Armengaud A [2Fe,2S] ferredoxin found in the photosynthetic bacterium Rhodobacter capsulatus has been purified in recombinant form from Escherichia coli. This protein, called FdVI, resembles ferredoxins involved in iron,sulfur cluster biosynthesis in various prokaryotic and eukaryotic cells. Purified recombinant FdVI was recovered in high yields and appeared to be indistinguishable from the genuine R. capsulatus ferredoxin based on UV,visible absorption and EPR spectroscopy and mass spectrometry. FdVI has been crystallized in the oxidized state by a sitting-drop vapour-diffusion technique using sodium formate as precipitant. Seeding larger drops from a previous hanging-drop-grown small crystal resulted in the formation of long red,brown prismatic needles. Preliminary X-ray diffraction analysis indicated that FdVI crystals are orthorhombic and belong to the space group P212121, with unit-cell parameters a = 45.87, b = 49.83, c = 54.29 Å. [source] Crystallization and preliminary crystallographic analysis of the catalytic module of endolysin from Cp-7, a phage infecting Streptococcus pneumoniaeACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 6 2010Noella Silva-Martin As part of the life cycle of the pneumococcal phage Cp-7, the endolysin Cpl-7 cleaves the glycosidic ,1,4 bonds between N -acetylmuramic acid and N -acetylglucosamine in the pneumococcal cell wall, resulting in bacterial lysis. Recombinant Cpl-7 was overexpressed in Escherichia coli, purified and crystallized using the vapour-diffusion method at 291,K. Diffraction-quality tetragonal crystals of the catalytic module of Cpl-7 were obtained from a mixture of PEG 3350 and sodium formate. The crystals belonged to space group I422, with unit-cell parameters a = 127.93, b = 127.93, c = 82.07,Å. Diffraction data sets were collected to 2.4,Å resolution using a rotating-anode generator. [source] Crystallization and preliminary X-ray crystallographic analysis of the [NiFe]-hydrogenase maturation factor HypF1 from Ralstonia eutropha H16ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 4 2010Gordon Winter The hydrogenase maturation factor HypF1 is a truncated but functional version of the HypF protein. HypF is known to be involved in the supply of the CN, ligands of the active site of [NiFe]-hydrogenases, utilizing carbamoyl phosphate as a substrate. The first crystallization and preliminary X-ray studies of HypF1 from Ralstonia eutropha H16 are reported here. Crystals of HypF1 (394 amino acids, 40.7,kDa) were obtained by the sitting-drop vapour-diffusion technique using sodium formate as a precipitant. The crystals belonged to space group I222, with unit-cell parameters a = 79.7, b = 91.6, c = 107.2,Å. Complete X-ray diffraction data sets were collected at 100,K from native crystals and from a platinum derivative to a maximum resolution of 1.65,Å. [source] Two-step counterdiffusion protocol for the crystallization of haemoglobin II from Lucina pectinata in the pH range 4,9ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 3 2010Carlos A. Nieves-Marrero Lucina pectinata haemoglobin II (HbII) transports oxygen in the presence of H2S to the symbiotic system in this bivalve mollusc. The composition of the haem pocket at the distal site includes TyrB10 and GlnE7, which are very common in other haem proteins. Obtaining crystals of oxyHbII at various pH values is required in order to elucidate the changes in the conformations of TyrB10 and GlnE7 and structural scenarios induced by changes in pH. Here, the growth of crystals of oxyHbII using the capillary counterdiffusion (CCD) technique at various pH values using a two-step protocol is reported. In the first step, a mini-screen was used to validate sodium formate as the best precipitating reagent for the growth of oxyHbII crystals. The second step, a pH screen typically used for optimization, was used to produce crystals in the pH range 4,9. Very well faceted prismatic ruby-red crystals were obtained at all pH values. X-ray data sets were acquired using synchrotron radiation of wavelength 0.886,Å (for the crystals obtained at pH 5) and 0.908,Å (for those obtained at pH 4, 8 and 9) to maximum resolutions of 3.30, 1.95, 1.85 and 2.00,Å for the crystals obtained at pH 4, 5, 8 and 9, respectively. All of the crystals were isomorphous and belonged to space group P42212. [source] Crystallization and preliminary X-ray diffraction analysis of the lectin from Canavalia boliviana Piper seedsACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 3 2009Tales Rocha Moura Plant lectins are the most studied group of carbohydrate-binding proteins. Despite the high similarity between the members of the Diocleinae subtribe (Leguminosae) group, they present differing biological activities. Canavalia boliviana lectin (Cbol) was purified using a Sephadex G-50 column and crystallized in the presence of X-Man by hanging-drop vapour diffusion at 293,K. After optimization, crystals suitable for diffraction were obtained under the condition 0.1,M HEPES pH 7.5 and 3.0,M sodium formate. The crystal belonged to the monoclinic space group C2, with unit-cell parameters a = 126.70, b = 66.64, c = 64.99,Å, , = 90.0, , = 120.8, , = 90.0°. Assuming the presence of a dimer in the asymmetric unit, the solvent content was estimated to be about 46%. A complete data set was collected at 1.5,Å resolution. [source] Crystallization and X-ray diffraction analysis of the RNA primer/promoter-binding domain of influenza A virus RNA-dependent RNA polymerase PB2ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 2 2009Takashi Kuzuhara The C-terminal domain protein (amino-acid residues 535,759) of the PB2 subunit of the RNA-dependent RNA polymerase from the highly pathogenic influenza A virus was expressed as a soluble protein in Escherichia coli and crystallized using sodium formate as a precipitant. Data sets were collected from crystals of native and selenomethionine-substituted protein on the KEK NW12 beamline at the Photon Factory and the crystals diffracted to a maximum resolution of 2.44,Å for the SeMet-derivative crystal. The native crystals were found to belong to space group P3221, with unit-cell parameters a = b = 52.5, c = 156.3,Å. The Matthews value (VM) was 2.7,Å3,Da,1, assuming the presence of one molecule in the asymmetric unit. The SeMet-derivative crystals were found to belong to the same space group, with unit-cell parameters a = b = 52.6, c = 156.4,Å. Attempts are being made to solve the structure by multi-wavelength anomalous dispersion phasing. [source] The asymmetric synthesis of (R,R)-formoterol via transfer hydrogenation with polyethylene glycol bound Rh catalyst in PEG2000 and waterCHIRALITY, Issue 2 2010Ling Huang Abstract (R,R)-formoterol was synthesized in seven steps with 4-hydroxyl-3-nitro-acetophenone as the starting material. The key intermediate, the chiral secondary alcohol 4, was prepared via Rh-catalyzed asymmetric transfer hydrogenation with (S,S)-PEGBsDPEN as the ligand and sodium formate as the hydrogen donor under mild conditions. With a mixture of PEG 2000 and water as the reaction media, the catalyst system could be recycled four times. Chirality, 2010. © 2009 Wiley-Liss, Inc. 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