1114-17-6Relevant academic research and scientific papers
KINETICS AND MECHANISM OF Ru(III) CATALYSED OXYDATION OF SOME POLYHYDRIC ALCOHOLS BY N-BROMOSUCCINIMIDE IN ACIDIC MEDIA
Sharma, J. P.,Singh, R. N. P.,Singh, A. K.,Singh, Bharat
, p. 2739 - 2748 (1986)
Kinetics of oxydation of ethylene glycol, glycerol, erythritol and dulcitol by acidic solution of N-bromosuccinimide (NBS) in presence of ruthenium(III) chloride as a homogeneous catalyst and mercuric acetate as scavenger in the temperature range of 30-50 deg C have been reported.The reactions follow identical kinetics, being first order in each NBS, substrate and Ru(III).Zero effect of , and ionic strength has been observed.A negative effect of succinimide and acetic acid is observed while shows the positive effect on reaction velocity.Various activation parameters have been computed.The products of the reaction were identified as the corresponding acids.A suitable mechanism consistent with the experimental results has been proposed.
Selective oxidation of uronic acids into aldaric acids over gold catalyst
Rautiainen, Sari,Lehtinen, Petra,Chen, Jingjing,Vehkam?ki, Marko,Niemel?, Klaus,Leskel?, Markku,Repo, Timo
, p. 19502 - 19507 (2015)
Herein, uronic acids available from hemicelluloses and pectin were used as raw material for the synthesis of aldaric acids. Au/Al2O3 catalyst oxidized glucuronic and galacturonic acids quantitatively to the corresponding glucaric and galactaric acids at pH 8-10 and 40-60 °C with oxygen as oxidant. The pH has a significant effect on the initial reaction rate as well as desorption of acid from the catalyst surface. At pH 10, a TOF value close to 8000 h-1 was measured for glucuronic acid oxidation. The apparent activation energy Ea for glucuronic acid oxidation is dependent on the pH which can be attributed to the higher energy barrier for desorption of acids at lower pH. This journal is
Oxidation of D-glucose by Cu(II) in acidic medium
Signorella, Sandra,Lafarga, Ruben,Ciullo, Laura,Sala, Luis F.
, p. 35 - 44 (1994)
The oxidation of D-glucose by Cu(II) has been studied in NaAcO buffers within the pH range 4-5 at 110 deg C.The observed pseudo-first-order rate constant is given by: a->+b/+> + c-> + d/+>2, where a = 5.3 +/- 0.4*10-4 s-1M-1, b = 1.30 +/- 0.07*10-8 s-1M, c = 6.16 +/- 0.04*10-3 s-1 M-2, and d = 3.2 +/- 0.2*10-13 s-1 M.This rate law corresponds to the formation of glutonic acid and Cu(I) when a ten-fold or higher excess of D-glucose over Cu(II) is employed.The results are discussed in terms of a possible mechanism of oxidation of D-glucose by CuOAc+, present in solution.
Hydroxyl radical-induced etching of glutathione-capped gold nanoparticles to oligomeric AuI-thiolate complexes
Chen, Tzu-Heng,Nieh, Chih-Chun,Shih, Ya-Chen,Ke, Chen-Yi,Tseng, Wei-Lung
, p. 45158 - 45164 (2015)
Thiol-induced core etching of gold nanoparticles is a general method for the production of gold nanoclusters (AuNCs) of various sizes. This paper is the first report on the efficient reaction of glutathione-capped gold nanoparticles (GSH-AuNPs) with hydroxyl radicals to produce oligomeric AuI-thiolate complexes at ambient temperature. Also, hydroxyl radicals can etch commercially available gold nanoparticles (100 nm); this strategy can be applied for the removal of gold from scrap electronics. Additionally, proteins can trigger the aggregation of oligomeric AuI-thiolate complexes under neutral conditions resulting in the formation of fluorescent AuNCs. For example, the reaction of trypsin, lysozyme, and glucose oxidase with oligomeric AuI-thiolate complexes produces Au5, Au8, and Au13 clusters with emission maxima at 415, 460, and 535 nm, respectively. Interestingly, trypsin- and glucose oxidase-stabilized AuNCs could sense GSH and glucose via GSH-induced etching of AuNCs and H2O2-mediated oxidation of AuNCs, respectively. This journal is
Efficient production of sugar-derived aldonic acids by Pseudomonas fragi TCCC11892
Mao, Shuhong,Liu, Yanna,Hou, Yali,Ma, Xiaoyu,Yang, Juanjuan,Han, Haichao,Wu, Jianlin,Jia, Longgang,Qin, Huimin,Lu, Fuping
, p. 39897 - 39901 (2018)
Aldonic acids are receiving increased interest due to their applications in nanotechnology, food, pharmaceutical and chemical industries. Microbes with aldose-oxidizing activity, rather than purified enzymes, are used for commercial production with limited success. Thus it is still very important to develop new processes using strains with more efficient and novel biocatalytic activities for the production of adonic acids. In the present study, Pseudomonas fragi TCCC11892 was found to be an efficient producer of aldonic acids, with the production of galactonic and l-rhamnonic acid by P. fragi reported for the first time. The semi-continuous production of maltobionic acid and lactobionic acid was developed for P. fragi TCCC11892, achieving a yield of over 90 g L?1 for the first 7 cycles. The excellent performance of P. fragi in the production of lactobionic acid (119 g L?1) was also observed when using waste cheese whey as an inexpensive fermentation medium. Scaling up of the above process for production of aldonic acids with P. fragi TCCC11892 cells should facilitate their commercial applications.
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 (1999)
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.
Enzymatic synthesis of aldonic acids
Pezzotti,Therisod
, p. 2290 - 2292 (2006)
Several aldonic acids (d-mannonic, d-galactonic, d-xylonic, 2-deoxy-d-arabinohexonic (2-deoxy-d-gluconic)) were prepared on a scale of several grams by a simple oxidation catalyzed by glucose oxidase in pure water.
Kinetics and mechanism of Pd(II) catalysed oxidation of D-arabinose, D-xylose and D-galactose by N-bromosuccinimide in acidic solution
Singh, Ashok Kumar,Chopra, Deepti,Rahmani, Shahla,Singh, Bharat
, p. 157 - 160 (1998)
The kinetics of Pd(II) catalysed oxidation of Ara, Xyl and Gal by N-bromosuccinimide (NBS) in acidic medium has been studied using Hg(OAc)2 as a scavenger for the Br- ion. The reaction data show that first-order kinetics in each pentose and hexose at low concentrations tend to zero-order at high concentrations. First-order kinetics with respect to NBS and Pd(II) and inverse fractional order, i.e., decreasing effect of [H+] and [Cl-], were observed, whereas ionic strength, Hg(OAc)2 and succinimide did not influence the oxidation rate. Various activation parameters have been calculated and recorded. The corresponding acids, arabonic, xylonic and galactonic, were identified as the main oxidation products of the reactions. On the basis of the experimental findings, a suitable mechanism has been proposed. Copyright (C) 1998 Elsevier Science Ltd.
Oxidation of threose-series pentoses and hexoses by sodium N-chloro-p- toluenesulfonamide
Rangappa, Kanchugarakoppal S.,Manjunathaswamy, Huchappa,Raghavendra, Manikanahally P.,Gowda, D. Channe
, p. 253 - 262 (1998)
The kinetics and mechanism of oxidation of threose-series hexoses and pentoses by chloramine-T in alkaline medium was investigated. Kinetic studies with D-galactose, D-sorbose, D-xylose, and D-lyxose showed that the rate of the reaction was first order with respect to sugar and chloramine-T, and second order with respect to hydroxide ion. p-Toluenesulfonamide and chloride ions, the reduced products of chloramine-T, have no effect on the reaction rate. The rate increases with increase in ionic strength of the medium, and the dielectric effect is negative. Proton inventory studies in H2O-D2O mixtures suggested a single transition state. Product analysis for D-gulose, Didose, L-sorbose, D-galactose, D-talose, D-tagatose, D-xylose, and D-lyxose revealed that all lyxoseseries hexoses gave mainly mixtures of lyxonic and threonic acids with minor proportions of hexonic, xylonic and glyceric acids, whereas all xylose-series hexoses gave mixtures of lyxonic, threonic and glyceric acids with minor amounts of xylonic and hexonic acids. Xylose and lyxose gave mixtures consisting mainly of lyxonic, threonic, and glyceric acids with minor proportions of xylonic acid. From the results of kinetic studies, reaction stoichiometry, and product analysis, a possible mechanism for the oxidation of threose-series sugars with chloramine-T is suggested.
Preparation method of gluconic acid
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Paragraph 0009; 0021; 0024-0059, (2019/06/05)
The invention discloses a method for preparing gluconic acid from glucose as a raw material with a catalytic oxidation means. Gluconic acid is prepared through oxidation of glucose by an aqueous phasewith air or oxygen as an oxidizing agent and a transition metal compound and nitrous acid or nitrite as a composite catalyst. The reaction is simple in operation and mild in condition, the glucose conversion rate is high, the selectivity of the gluconic acid product is good, and the method has important application prospects.
