壳聚糖的分子量调控。I：亚硝酸解聚动力学。

Molecular weight manipulation of chitosan. I: Kinetics of depolymerization by nitrous acid.

作者信息

Allan G G, Peyron M

机构信息

Department of Chemical Engineering, University of Washington, Seattle 98195, USA.

出版信息

Carbohydr Res. 1995 Nov 22;277(2):257-72. doi: 10.1016/0008-6215(95)00207-a.

DOI:10.1016/0008-6215(95)00207-a

PMID:8556735

Abstract

The kinetics of the depolymerization of chitosan in dilute aqueous HCl solutions by nitrous acid were studied. The rate of depolymerization is independent of the molecular weight of chitosan, first order with respect to the concentrations of both nitrous acid and glucosamine moieties, not catalysed by either hydrogen or chloride ions, and Arrhenius temperature dependent. Chitosan exhibits significantly decreased reactivity as the degree of deacetylation of the polymer increases. These results are consistent with a depolymerization reaction mechanism in which the rate-limiting step is nitrosation of the unprotonated amine by nitrous acidium ion.

摘要

研究了壳聚糖在稀盐酸水溶液中被亚硝酸解聚的动力学。解聚速率与壳聚糖的分子量无关，对亚硝酸和葡糖胺部分的浓度均为一级反应，不受氢离子或氯离子催化，且符合阿累尼乌斯温度依赖性。随着聚合物脱乙酰度的增加，壳聚糖的反应活性显著降低。这些结果与一种解聚反应机理一致，其中限速步骤是亚硝酸根离子对未质子化胺的亚硝化反应。