在醋酸钠-醋酸缓冲介质中某些糖及糖磷酸盐对金(III)的反应活性

Reactivity of some sugars and sugar phosphates towards gold(III) in sodium acetate-acetic acid buffer medium.

作者信息

Sen Gupta K K, Pal B, Begum B A

机构信息

Department of Chemistry, Jadavpur University, Calcutta, India.

出版信息

Carbohydr Res. 2001 Jan 15;330(1):115-23. doi: 10.1016/s0008-6215(00)00181-6.

DOI:10.1016/s0008-6215(00)00181-6

PMID:11217954

Abstract

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.

摘要

在不同温度下，于醋酸钠 - 醋酸缓冲介质中通过分光光度法研究了一些醛糖和醛糖磷酸酯的氧化动力学。反应对[Au(III)]和[底物]均为一级反应。H⁺和Cl⁻离子均会使反应速率减慢。反应似乎涉及不同的金(III)物种，即AuCl₄⁻、AuCl₃(OH₂)和AuCl₃(OH)⁻。根据自由基和Au(II)可能的中间产物形成对结果进行了解释。醛糖与金(III)反应的顺序为：丙糖＞丁糖＞戊糖＞己糖。除葡萄糖 - 1 - 磷酸酯反应速率比葡萄糖慢外，糖磷酸酯与金(III)反应的速率比相应的母体糖快。已提出了一个导致产物形成的初步反应机理。