Reactivity of some sugars and sugar phosphates towards gold(III) in sodium acetate-acetic acid buffer medium.
The kinetics of the oxidation of some aldoses and aldose phosphates have been studied spectrophotometrically in sodium acetate-acetic acid buffer medium at different temperatures. The reactions are first order with respect to [Au(III)] and [substrate]. Both H+ and Cl- ions retard the reaction. The reactions appear to involve different gold(III) species, viz. AuCl4-, AuCl3(OH2) and AuCl3(OH)- . The results are interpreted in terms of the probable intermediate formation of free radicals and Au(II). Aldoses react with gold(III) in the order: triose > tetrose > pentose > hexose. The sugar phosphates react with gold(III) at a faster rate than the parent sugars except glucose-1-phosphate, which reacts at slower rates than glucose. A tentative reaction mechanism leading to the formation of products has been suggested.
Sen Gupta
K K
KK
Department of Chemistry, Jadavpur University, Calcutta, India.
Pal
B
B
Begum
B A
BA
D000447:Aldehydes / Q000378:metabolism; D018501:Antirheumatic Agents / Q000378:metabolism; D002021:Buffers; D050260:Carbohydrate Metabolism; D002712:Chlorides / Q000494:pharmacology; D005609:Free Radicals / Q000378:metabolism; D006046:Gold / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D009005:Monosaccharides / Q000378:metabolism; D016877:Oxidants / Q000378:metabolism; D010084:Oxidation-Reduction; D019346:Sodium Acetate; D013403:Sugar Phosphates / Q000378:metabolism*; D013816:Thermodynamics
D000447:Aldehydes; D018501:Antirheumatic Agents; D002021:Buffers; D002712:Chlorides; D005609:Free Radicals; D009005:Monosaccharides; D016877:Oxidants; D013403:Sugar Phosphates; D019346:Sodium Acetate; D006046:Gold