摘要
[Objective] In order to study the relations among different positions, degrees of substitution and antioxidant ability. [Method] N, O-carboxymethyl chitosan （NOA, NOB and NOC）with various degrees of substitution （DS）were obtained by etherizing chito-oligosacchaside. Their structure and substituted degree were characterized and their antioxldant activity to·OH was evaluated. [ Result] The IC50 s of NOA ,NOB and NOC were 0.15 ,0. 29 ,0. 23 mg/ml while their DSs of -NH2 position（DSN） were 0.51,0.29 and 0.38 and DSo were 0. 74 ,0. 84 ,0. 97respectively.[ Conclusion] With the increase of DSN ,antioxidant activity of N,O-carboxymethyl chitosan oligosaccharide to·OH was up.
壳聚糖是一种来源于甲壳类动物外壳的天然碱性多糖，有良好的抗氧化能力。羧甲基壳聚糖是壳聚糖经羧甲基化后的一类衍生物，根据羧甲基的取代位置不同，羧甲基壳聚糖可以分为O-羧甲基壳聚糖、N-羧甲基壳聚糖和N，O-羧甲基壳聚糖。有研究表明，羧甲基在多糖主链上取代的位置和程度都直接影响羧甲基壳聚糖的各种性能。笔者以低聚壳聚糖（Chitosan oligosaccharide，COS）为原料，
基金
Supported by Shanghai Leading Academic Discipline(Project No.T1102)
Shanghai Commission of Education Scientific Research Project(07zz134)~~
