- PROCESSES FOR PREPARING ALDARIC, ALDONIC, AND URONIC ACIDS
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Various processes for preparing aldaric acids, aldonic acids, uronic acids, and/or lactone(s) thereof are described. For example, processes for preparing a C5-C6 aldaric acid and/or lactone(s) thereof by the catalytic oxidation of a C5-C6 aldonic acid and/or lactone(s) thereof and/or a C5-C6 aldose are described.
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Paragraph 0132-0143
(2021/05/29)
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- Base-free selective oxidation of pectin derived galacturonic acid to galactaric acid using supported gold catalysts
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Agricultural residues like sugar beet pulp (SBP) are an interesting feedstock for the production of 2nd generation bio-based chemicals and materials. The pectin fraction of SBP is rich in galacturonic acid (GalA), a C6 sugar acid. The oxidation of this uronic acid at C1 yields galactaric acid (GA), which has several industrially interesting properties. It was previously shown that the Au catalysed oxidation of uronic acids under basic conditions is highly effective, yet leads to the co-production of salts. Hence, here we report for the first time on the oxidation of an acidic carbohydrate substrate, GalA, at its autogenic pH (2.2) in water, using carbon supported gold nanoparticles, under mild conditions in the presence of molecular oxygen. The comparison of the Au/C catalyst prepared by a colloidal deposition method with benchmark commercially available metal oxide supported gold catalysts shows that under acidic conditions, the Au/C catalyst is more active and more selective than Au/TiO2, and more stable than Au/Al2O3. The difference in selectivity is attributed to the H2O2 mediated chain scission reaction of the substrate (GalA) which is observed only in the case of metal oxide supported Au catalysts. The Au/C catalyst shows 100% GA selectivity at 76% GalA conversion (333 K, 21 h batch time) and a GA yield of up to 95% was obtained at 353 K. Detailed characterization of the fresh and spent Au/C catalysts by ICP-OES, TEM and XPS analyses showed no gold leaching, particle sintering or change in metal composition. The Au/C catalyst was fully regenerated by a mild alkaline wash, and used in five consecutive runs without any significant decrease in activity or selectivity. Labelling experiments with 18O2 and H218O2 revealed that under base-free conditions, the oxygen incorporated in the aldaric acid originates from the solvent water.
- Pazhavelikkakath Purushothaman, Rajeesh Kumar,Klis, F. Van Der,Frissen,Haveren, J. Van,Mayoral,Van Der Bent,Van Es
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supporting information
p. 2763 - 2774
(2018/07/03)
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- OXIDATION OF URONIC ACIDS TO ALDARIC ACIDS
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Disclosed is the oxidation of uronic acids, such as galacturonic acid, to the corresponding aldaric acids, such as galactaric acid, under neutral or acidic conditions. Use is made of a supported gold catalyst. The oxidation occurs in good selectivity and yield, under unexpectedly mild conditions. A source of galacturonic acids is pectins, such as from sugar beet pulp.
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Paragraph 0032; 0037
(2017/11/10)
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- Biological Activities of Phenolics from the Fruits of Phyllanthus emblica L. (Euphorbiaceae)
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Seven phenolic compounds, 1 – 7, including a new organic acid gallate, mucic acid 1-ethyl 6-methyl ester 2-O-gallate (7), were isolated from the MeOH extract of the fruits of Phyllanthus emblica L. (Euphorbiaceae). The structures were elucidated on the basis of extensive spectroscopic analysis and comparison with literature data. Upon evaluated for their antioxidant abilities by 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2′-azinobis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), and ferric reducing antioxidant power (FRAP) assays. The inhibitory activities against melanogenesis in B16 melanoma cells induced by α-MSH, as well as cytotoxic activities against four human cancer cell lines were also evaluated. All phenolic compounds, 1 – 7, exhibited potent antioxidant abilities (DPPH: IC50 5.6 – 12.9 μm; ABTS: 0.87 – 8.43 μm Trolox/μm; FRAP: 1.01 – 5.79 μm Fe2+/μm, respectively). Besides, 5 – 7, also exhibited moderate inhibitory activities against melanogenesis (80.7 – 86.8% melanin content), even with no or low toxicity to the cells (93.5 – 101.6% cell viability) at a high concentration of 100 μm. Compounds 1 – 3 exhibited cytotoxic activity against one or more cell lines (IC50 13.9 – 68.4%), and compound 1 with high tumor selectivity for A549 (SI 3.2).
- Zhang, Jie,Miao, Dan,Zhu, Wan-Fang,Xu, Jian,Liu, Wen-Yuan,Kitdamrongtham, Worapong,Manosroi, Jiradej,Abe, Masahiko,Akihisa, Toshihiro,Feng, Feng
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- Novel synthetic process of mucic acid
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The present invention relates to a method of synthesizing mucic acid from galactose derived from biomass including marine resources, and more specifically, to a method of synthesizing mucic acid which utilizes galactose as a starting material and through a chemical reaction, induces an oxidation reaction to synthesize mucic acid. The method of the present invention can easily synthesize mucic acid in a high yield from galactose and the like under low temperature and atmospheric pressure operating conditions, can be used as an intermediate to produce bio adipic acid, the raw material of nylon 66 that is used as a material for automobile parts, and, therefore, has high industrial applicability.(AA) Marine bio sugar mixture obtained after saccharification using non-food marine resources (galactose, or a mixture of galactose, glucose and rhamnose)(BB) Mixing of aqueous nitric acid solution with sugar mixture(CC) Oxidation reaction of bio sugar under low temperature condition (-15~0anddeg;C)(DD) Washing of solid products produced from chemical reaction and extraction of high-purity mucic acid particles using aqueous solution, having mucic acid dissolved therein, prepared in advanceCOPYRIGHT KIPO 2017
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Paragraph 0035-0037; 0067
(2017/06/10)
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- Production of Adipic Acid from Sugar Beet Residue by Combined Biological and Chemical Catalysis
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Adipic acid is one of the most important industrial dicarboxylic acids and is used mainly as a precursor to nylon-6,6. Currently, commercial adipic acid is produced primarily from benzene by a chemical route that is associated with environmental, health, and safety concerns. Herein, we report a new process to produce adipic acid from an inexpensive renewable feedstock, sugar beet residue by combining an engineered Escherichia coli strain and Re-based chemical catalysts. The engineered E.coli converted d-galacturonic acid to mucic acid, which was precipitated easily with acid, and the mucic acid was further converted to adipic acid by a deoxydehydration reaction catalyzed by an oxorhenium complex followed by a Pt/C-catalyzed hydrogenation reaction under mild conditions. A high selectivity to the free acid products was achieved by tuning the acidity of the Re-based catalysts. Finally, adipic acid was produced directly from sugar beet residue that was hydrolyzed enzymatically with engineered E.coli and two chemical catalysts in a yield of 8.4 %, which signifies a new route for the production of adipic acid.
- Zhang, Hongfang,Li, Xiukai,Su, Xiaoyun,Ang, Ee Lui,Zhang, Yugen,Zhao, Huimin
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p. 1500 - 1506
(2016/05/02)
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- Selective oxidation of uronic acids into aldaric acids over gold catalyst
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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
- Rautiainen, Sari,Lehtinen, Petra,Chen, Jingjing,Vehkam?ki, Marko,Niemel?, Klaus,Leskel?, Markku,Repo, Timo
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p. 19502 - 19507
(2015/04/28)
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- CATALYTIC OXIDATION OF URONIC ACIDS TO ALDARIC ACIDS
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Disclosed is the oxidation of uronic acids, such as galacturonic acid, to the corresponding aldaric acids (characterized by the formula HOOC-(CHOH)n-COOH, with n being an integer of from 1 to 5) such as galactaric acids. The starting material comprising the uronic acid is subjected to oxygen under the influence of a supported gold catalyst and in the presence of a base. The oxidation occurs in good selectivity and yield, under unexpectedly mild conditions. A source of galacturonic acids is pectin, such as that derived from sugar beet pulp.
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Page/Page column 12-13
(2013/10/22)
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- D-galacturonic acid as a highly reactive compound in nonenzymatic browning. 1. Formation of browning active degradation products
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Thermal treatment of an aqueous solution of d-galacturonic acid at pH 3, 5, and 8 led to rapid browning of the solution and to the formation of carbocyclic compounds such as reductic acid (2,3-dihydroxy-2-cyclopenten-1-one), DHCP (4,5-dihydroxy-2-cyclopenten-1-one), and furan-2-carbaldehyde, as degradation products in weak acidic solution. Studies on their formation revealed 2-ketoglutaraldehyde as their common key intermediate. Norfuraneol (4-hydroxy-5-methyl-3-(2H)-furanone) is a typical alkaline degradation product and formed after isomerization. Further model studies revealed reductic acid as an important and more browning active compound than furan-2-carbaldehyde, which led to a red color of the model solution. This red-brown color is also characteristic of thermally treated uronic acid solutions.
- Bornik, Maria-Anna,Kroh, Lothar W.
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p. 3494 - 3500
(2013/06/05)
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- Photoinduced electron transfer in pentacoordinated complex of zinc tetraphenylporphyrin and isoquinoline N-oxide. Crystal structure, spectroscopy and DFT studies
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A novel, pentacoordinated complex of (1:1) zinc tetraphenylporphyrin and isoquinoline N-oxide (ZnTPP-IQNO) was synthesized and its crystal structure along with photophysical properties by experimental methods (absorption, steady state and time-resolved emission) in conjunction with DFT and TD DFT calculations were investigated. In ZnTPP-IQNO complex, the isoquinoline N-oxide ligand (IQNO) is directly coordinated to the central zinc atom of the ZnTPP unit through the oxygen atom of the NO group and crystallizes in centrosymmetric triclinic unit, in the space group P1. Particular contacts between the two monomeric units (hydrogen bonds, O...H-C interactions, ...etc.) lead to a supramolecular dimer which forms the layers propagating both along the a and the b-axis. The electronic locally excited and the charge-transfer states of the complex were calculated by TDDFT CAM-B3LYP/6-31G(d,p) method. A surprising presence of the charge transfer states between the Soret and the Q bands leads to excitation energy dissipation processes involving the opening of the radiationless channels of excited ZnTPP-IQNO complex. Emission from the S 1 state (Q band) in ethyl acetate decays accordingly to monoexponential function (1.92 ns) while a bi-exponential decay is found in n-propanol [(2.5 ns (87%); 14.4 ns (13%)] and in the solid state [1.36 ns (67.5%), 7.31 ns (32.5%)].
- Oberda,Deperasinska,Nizhnik,Jerzykiewicz,Szemik-Hojniak
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body text
p. 2391 - 2399
(2011/10/10)
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- Lamiaceae carbohydrates. 1. Pectinic substances and hemicelluloses from Mentha x piperita
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Pectinic substances from the aerial part of Mentha x piperita were isolated and characterized and found to be a mixture of β-(1→4)-glucogalactan (MPG) and two α-(1→4)-rhamnopolygalacturonans (MPP'-1 and MPP'-2). It was shown that the pectin and its components exhibited membrane-stabilizing, antiatherogenic, and antioxidant activity. Hemicelluloses from M. piperita were a lignocarbohydrate complex.
- Olennikov,Tankhaeva
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p. 501 - 507
(2008/03/27)
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- Kinetic and mechanistic investigation of oxidation of uronic acids by sodium N-bromoarylsulfonamides in alkaline medium
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The kinetics of oxidation of uronic acids (UAs), D-glucuronic acid and D-galacturonic acid, by sodium N-bromo-p-toluenesulfonamide or bromamine-T (BAT) and sodium N-bromobenzenesulfonamide or bromamine-B (BAB) in alkaline medium at 30°C have been investigated and the rate law, rate=k [OX] [UA] [HO-] where [OX][BAT] or [BAB] was observed. The product p-toluenesulfonamide (PTS) or benzenesulfonamide (BSA) and ionic strength have no influence on the rate. The rate decreased when the dielectric constant (ε) of the medium was decreased. The rate increased in D2O medium. Proton inventory studies were made in D2O-H2O mixtures. Effect of temperature was studied and from the Arrhenius plots, activation parameters were computed. A mechanism involving the formation of enediol anion, which reacts with positive bromine of the bromamine in the rate-limiting step is suggested.
- Shashikala,Rangappa
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p. 491 - 499
(2007/10/03)
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- Synthesis and conformational analysis of seco C-nucleosides and their diseco double-headed analogues of the 1,2,4-triazole, 1,2,4-triazolo[3,4-b]1,3,4-thiadiazole
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Reaction of d-glucono- (1) or d-galactono- (2) 1,5-lactones and d-glycero-d-guloheptonic-1,4-lactone (11) with thiocarbohydrazide (3) afforded the seco C-nucleosides 4-amino-3-(d-gluco- (4) or d-galacto- (5) pentitol-1-yl)-5-mercapto-1,2,4-triazoles and 4-amino-3-(d-glycero-d-gulo-hexitol-1-yl)-5-mercapto-1,2,4-triazole (12). Their conversions to the 3-(1,2,3,4,5-penta-O-acyl-d-gluco- (7 and 9) or the d-galacto (8 and 10) pentitol-1-yl)-6-substituted 1,2,4-triazolo[3,4-b]1,3,4-thiadiazole and 3-(1,2,3,4,5,6-hexa-O-acetyl-d-glycero-d-gulohexitol-1-yl)-6-methyl-1,2,4-triazolo[3,4-b]1,3,4-thiadiazole (13) were achieved under acylative conditions. Reaction of diethyl galactrate (17) with 3 gave 1,4-bis (4-amino-5-mercapto-1,2,4-triazol-3-yl)-galacto-tetritol (18), which upon reaction with acetic anhydride gave 1,4-bis(6-methyl-1,2,4-triazolo[3,4-b]1,3,4-thiadiazol-3-yl)-1,2,3,4-tetra-O-acetyl-galacto-tetritol (19). When the tetra-O-acetylgalactaric acid (15) was used instead of 17, the attack of 3 had taken place on the ester group rather than the carboxylic group, whereby 16 was obtained rather than the tetra-O-acetyl derivative of 18. The structures were confirmed by using 1H,13C and 2D NMR spectra (DQFCOSY and HMQC) experiments. The vicinal coupling constants were used to deduce the favored conformations. Copyright (C) 1997 Elsevier Science Ltd.
- Awad, Laila F.,El Ashry, El Sayed H.
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- Kinetics and mechanism of the oxidation of uronic acdis by sodium N-chlorobenzenesulphonamide in alkaline medium
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The kinetics of oxidation of D-glucuronic acid and D-galacturonic acid (UA) by sodium N-chlorobenzenesulphonamide or chloramine-B (CAB) in alkaline medium at 35°C has been investigated and the rate law, rate = k [CAB][UA][HO-] was observed. The product, benzenesulphonamide had no influence. Increase of ionic strength increased the rate and when the dielectric constant of the medium was decreased, the rate was decreased. The rate increased in D2O medium and the inverse solvent isotope effect k (D2O)/k (H2O) was 2.00. Proton inventory was studied for the reactions in H2O-D2O mixtures. Activation parameters have been determined from the Arrhenius plots. The mechanism assumes the formation of an enediol anion followed by its oxidation by the positive halogen in a rate limiting step.
- Rangappa,Raghavendra,Mahadevappa
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p. 359 - 371
(2007/10/03)
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- Cosmetic composition
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A composition suitable for topical application to mammalian skin and hair for inducing, maintaining or increasing hair growth comprises a hair growth promoter chosen from glutamine derivatives and salts thereof. The composition preferably also comprises an activity enhancer which may be chosen from hair growth stimulants, penetration enhancers and cationic polymers.
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- Oxidation of uronic acids by sodium N-chloro-p-toluenesulphonamide in alkaline medium : A kinetic study
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Kinetics of oxidation of D-glucuronic acid and D-galacturonic acid (S) by sodium N-chioro-p-toluenesulphonamide or chloramine-T (CAT) in the presence of alkali at 35° has been investigated and the rate=k [CAT][S][HO-]. The product, p-toluenesulphonamide has no influence. Increase in ionic strength increases the rate and the rate decreases when the dielectric constant of the medium is decreased; The rate increases in D2O medium. Activation parameters have been determined from the Arrhenius plots. The mechanism involves the formation of an enediol anion followed by its oxidation by the positive halogen in a rate limiting step.
- Raghavendra,Mahadevappa,Rangappa
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p. 1079 - 1083
(2007/10/03)
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- Cosmetic composition containing DOPA derivatives
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A composition for topical application to human hair or skin contains a chemical analogue of dihydroxyphenyl alanine (DOPA). This chemical analogue can be absorbed by skin or by a hair follicle and metabolised in-vivo, thus leading to the formation of melanin in skin or to the growth of melanin-pigmented hair. Consequently the composition can give controlled skin darkening to mimic sun-induced tanning or can bring about the growth of dar hair in place of the grey or white hair.
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- Cosmestic composition
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A composition suitable for topical application to mammalian skin and hair for inducing, maintaining or increasing hair growth comprises a hair growth promoter chosen from glutamic acid derivatives and salts thereof. The composition preferably also comprises an activity enhancer which may be chosen from hair growth stimulants, penetration enhancers and cationic polymers.
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- Cosmetic composition
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A composition suitable for topical application to mammalian skin and hair for inducing, maintaining or increasing hair growth comprises a hair growth promoter selected from: glutamine; 3-hydroxybutyric acid; acetoacetic acid; palmitic acid; and salts thereof. The composition preferably also comprises an activity enhancer which may be chosen from hair growth stimulants, penetration enhancers and cationic polymers.
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- Hair growth composition containing citric acid esters
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Triesters of citric acid are used for inducing, maintaining or increasing hair growth. Compositions for topical application to mammalian hair or scalp comprise an effective amount of from 1% to 99% by weight of an ester of citric acid having the structure (1): where, R1, R2 and R3 each independently represent a branched or unbranched alkyl, alkenyl, aryl, alkylaryl or arylalkyl group, each said group having from 1 to 18 carbon atoms, R4 represents -H, or a branched or unbranched saturated or unsaturated acyl, alkyl, aryl, alkylaryl or aylalkyl group having from 1 to 18 carbon atoms, in the presence of a cosmetically acceptable vehicle for the citric acid ester and in the absence of solid absorbent for the ester;, said effective amount of said ester being sufficient to increase hair growth in the rat, when said composition is applied topically thereto over a period of no more than three months, by at least 10% more than that obtainable using a control composition from which the said ester has been omitted, in accordance with the Rat Hair Growth Test.
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- Kinetics and Mechanism of Oxidation of Xylitol and Galactitol by Hexacyanoferrate(III) Ion in Aqueous Alkaline Medium
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Kinetics of oxidation of xylitol and galactitol by hexacyanoferrate(III) ion in aqueous alkaline medium is reported.The reaction rate is of first order with respect to hexacyanoferrate(III) in each substrate.The reaction is first order at lower concentrations of xylitol and galactitol and tends towards zero order as the concentration increases.Similarly first order kinetics was obtained with respect to hydroxide ion at lower concentrations and tends to lower order at higher concentration in the oxidation of xylitol; in the oxidation of galactitol the reaction isfirst order with respect to hydroxide ion even up to manyfold variation.The course of reaction has been considered to proceed through the formation of an activated complex between (2-) and substrate anion which decomposes slowly into radical and (3-).A probable reaction mechanism is proposed. - Keywords: Galactitol; Kinetics; Mechanism; Oxidation; Reduction; Xylitol
- Singh, H. S.,Singh, V. P.,Arya, B. S.,Varma, G. R.
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p. 1253 - 1260
(2007/10/02)
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