488-16-4Relevant articles and documents
Kinetics and mechanism of Ru(III) and Hg(II) co-catalyzed oxidation of D-galactose and D-ribose by N-bromoacetamide in perchloric acid
Singh, Ashok Kumar,Singh, Vineeta,Singh, Ajaya Kumar,Gupta, Neena,Singh, Bharat
, p. 345 - 351 (2002)
Kinetics of oxidation of reducing sugars D-galactose (Gal) and D-ribose (Rib) by N-bromoacetamide (NBA) in the presence of ruthenium(III) chloride as a homogeneous catalyst and in perchloric acid medium, using mercuric acetate as a scavenger for Br-
Reaction pathways of glucose oxidation by ozone under acidic conditions
Marcq, Olivier,Barbe, Jean-Michel,Trichet, Alain,Guilard, Roger
experimental part, p. 1303 - 1310 (2009/12/01)
The ozonation of d-glucose-1-13C, 2-13C, and 6-13C was carried out at pH 2.5 in a semi-batch reactor at room temperature. The products present in the liquid phase were analyzed by GC-MS, HPAEC-PAD, and 13C NMR s
Kinetic study of iridium(III) catalyzed oxidation of D-mannitol and erythritol by N-bromosuccinimide in acidic medium
Srivastava, Sheila,Gupta, Vandana
, p. 1103 - 1106 (2008/02/04)
Kinetic investigations on iridium trichloride catalyzed oxidation of D-mannitol and erythritol by acidic solution of N-bromosuccinimide (NBS) in the presence of mercuric acetate as a scavenger for Br- have been carried out in the temperature range 30-45 °C. The reactions follow identical kinetics. The rate shows a first-order dependence on [NBS] in lower concentration range which tends to zero-order at its higher concentrations. A first-order dependence on [IrIII] is also observed. Negligible effect of [substrate], [Hg(OAc)2] and ionic strength have been observed. Addition of [H+], [Cl-] and succinimide shows a negative effect. Activation parameters have been computed and a suitable mechanism conforming to above results has been proposed.
Kinetics and mechanism of oxidation of D-fructose and D-glucose by sodium salts of N-(chloro)-mono/di-substituted benzenesulfonamides in aqueous alkaline medium
Gowda, B. Thimme,Damodara,Jyothi
, p. 572 - 582 (2007/10/03)
In an effort to introduce N-chloroarylsulfonamides of different oxidizing strengths, nine sodium salts of mono- and di-substituted N- chloroarylsulfonamides are employed as oxidants for studying the kinetics of oxidation of D-fructose and D-glucose in aqueous alkaline medium. The results are analyzed along with those by the sodium salts of N-chlorobenzenesulfonamide and N-chloro-4-methylbenzenesulfonamide. The reactions show first-order kinetics each in [oxidant], [Fru/Glu], and [OH-]. The rates slightly increase with increase in ionic strength of the medium. Further, the rate of oxidation of fructose is higher by 4 to 5 times than that of the glucose oxidation, by the same oxidant. Similarly, Ea values for glucose oxidations are higher by about 1.5 times the Ea values for fructose oxidations. The results have been explained by a plausible mechanism, and the related rate law deduced. The significant changes in the kinetics and thermodynamic data are observed with change of substituent in the benzene ring. It is because Cl + is the effective oxidizing species in the reactions of N-chloroarylsulfonamides. The oxidative strengths of the latter therefore depend on the ease with which Cl+ is released from them. The ease with which Cl+ is released from N-chloroarylsulfonamides depends on the electron density of the nitrogen atom of the sulfonamide group, which in turn depends on the nature of the substituent in the benzene ring. The following Hammett equations are valid for the oxidation of fructose and glucose, log kobs = -3.13 + 0.54 σ ρ and log kobs = -3.81 + 0.28 σ ρ, respectively. The enthalpies and entropies of activations for oxidations by all the N-chloroarylsulfonamides correlate well with isokinetic temperatures of 301 K and 299 K, for fructose and glucose oxidations, respectively. The effect of substitution in the oxidants on the Ea and log A for the oxidations is also considered.
Ruthenium (III) catalysis of periodate oxidation of reducing sugars in aqueous alkaline medium
Singh, Ashok Kumar,Gupta, Neena,Rahmani, Shahla,Singh, Vinod Kumar,Singh, Bharat
, p. 1871 - 1875 (2007/10/03)
The ruthenium (III) catalysis of periodate oxidation of D-ribose, D-sorbose and maltose in aqueous alkaline medium has been investigated. The reactions have been found to be zero order with respect to each reducing sugar and first order with respect to ruthenium (III). The linear dependence of the reaction rate at lower concentrations of periodate ion and hydroxide ion tends towards zero order at their higher concentrations. Positive effect of [Cl -] on the rate of reaction has also been observed. The observed kinetics with periodate ion, under the conditions [IO4 -]〉〉[Ru(III)]T suggests the formation of a 1:1 complex between Ru(III) and periodate in the rate controlling step, which subsequently interacts with reactive species of reducing sugar to give the final products, through a series of fast steps. The rate law is derived.
A novel mechanism for the oxidation of erythro-series pentoses and hexoses by N-arylbromosulphonamides in alkaline medium
Shashikala,Rangappa
, p. 219 - 234 (2007/10/03)
Kinetic studies of the oxidation of D-mannose, D-glucose, D-fructose, L-arabinose and D-ribose by bromamine-T (sodium N-bromo-p-toluenesulphonamide or BAT) and bromamine-B (sodium N-bromobenzenesulphonamide or BAB) in alkaline medium were investigated at 30°C. The rate of the reaction was first order both with respect to the oxidant and the sugar and second order with respect to [HO-]. The addition of the reaction product, p-toluenesulphonamide (PTS) or benzenesulphonamide (BSA), and the variation of ionic strength of the medium have no effect on the rate. The rate decreases with decrease in dielectric constant of the medium and values of dAB, the size of activated complex, were calculated. Proton inventory studies were made in H2O-D2O mixtures. The activation parameters of the reaction were computed from Arrhenius plots. HPLC and GLC-MS analysis of the products indicated that the sugars were oxidized to a mixture of aldonic acids consisting of arabinonic, ribonic, erythronic and glyceric acids. A general mechanism consistent with the observed results has been proposed.
Kinetics and mechanism of oxidation of hexoses by bromamine-T in alkaline medium
Prashanth,Mantelingu,Murthy, A. S. Ananda,Anitha,Rangaswamy,Rangappa
, p. 241 - 245 (2007/10/03)
The kinetics and mechanism of oxidation of D-glucose and D-mannose with bromamine-T in alkaline medium have been studied and the rate = κ[BAT][sugar][OH-]2, is observed. The rate of the reaction is influenced by a change in ionic strength of the medium and the dielectric effect is found to be positive. The latter enables the computation of dAB, the size of the activated complex. Proton inventory studies are made for the reactions in H2O-D2O mixtures. Activation parameters are calculated from the Arrhenius plots. The product analyses indicates that the sugars are oxidized to a mixture of aldonic acids, consisting of arabinonic, ribonic, erythronic and glyceric acids. A mechanism consistent with the observed kinetics has been proposed.
Electrooxidation of mesoerythritol on platinum, modified or not by adatoms, in acid medium
Cherqaoui,Chbihi,Takky,Kokoh,Leger,Lamy
, p. 510 - 521 (2007/10/03)
The electrocatalytic oxidation of meso-erythritol has been studied in 0.1 M HClO4 on platinum and on adatoms modified platinum. Preliminary investigations by cyclic voltammetry showed that erythritol was not reactive on a Pt electrode. Underpotential deposition of lead or thallium adatoms at platinum allowed to increase significantly the current densities. Long-time electrolyses were carded out using a three potential plateau program with different values of the oxidation potentials. Chromatographic analyses showed that the oxidation of erythritol led mainly to erythrose, erythrulose and to erythronic acid. Otherwise, electrolysis of erythritol on a Pt-Tl modified electrode orientated selectively the distribution of the reaction products towards the formation of erythrulose.
The reaction of hyaluronic acid and its monomers, glucuronic acid and N- acetylglucosamine, with reactive oxygen species
Jahn, Michael,Baynes, John W.,Spiteller, Gerhard
, p. 228 - 234 (2007/10/03)
Synovial fluid is a ~0.15% (w/v) aqueous solution of hyaluronic acid (HA), a polysaccharide consisting of alternating units of GlcA and GlcNAc. In synovial fluid of patients suffering from rheumatoid arthritis, HA is thought to be degraded either by radicals generated by Fenton chemistry (Fe2+/H2O2) or by NaOCl generated by myeloperoxidase. We investigated the course of model reactions of these two reactants in physiological buffer with HA, and with the corresponding monomers GlcA and GlcNAc. meso-Tartaric acid, arabinuronic acid, arabinaric acid and glucaric acid were identified by GC-MS as oxidation products of glucuronic acid. When GlcNAc was oxidised, erythronic acid, arabinonic acid, 2-acetamido-2-deoxy-gluconic acid, glyceric acid, erythrose and arabinose were formed. NaOCl oxidation of HA yielded meso-tartaric acid; in addition, arabinaric acid and glucaric acid were obtained by oxidation with Fe2+/H2O2. These results indicate that oxidative degradation of HA proceeds primarily at glucuronic acid residues. meso-Tartaric acid may be a useful biomarker of hyaluronate oxidation since it is produced by both NaOCl and Fenton chemistry.
Kinetics and mechanism of the oxidation of some aldoses, amino sugars and methylated sugars by tris(pyridine-2-carboxylato)manganese(III) in weakly acidic medium
Gupta, Kalyan Kali Sen,Begum, Bilkis Ara
, p. 70 - 75 (2007/10/03)
The kinetics of oxidation of some aldoses, amino sugars and methylated sugars by tris(pyridine-2-carboxylato)manganese(III) have been studied spectrophotometrically in sodium picolinate -picolinic acid buffer medium. The reactions are first order with respect to both manganese(III) and sugar concentrations, but independent with respect to sodium picolinate - picolinic acid buffer medium. The mechanism for the reactions is discussed.
