不同取代度O-羧甲基壳聚糖的抗氧化性能

Preparation of O-carboxymethyl chitosan oligosaccharide with different substituting degrees and their antioxidant activity

低聚壳聚糖经醚化得到O-羧甲基壳聚糖OA、OB和OC,取代度(DS)分别为0.54、0.38和0.31,对其结构进行表征,并考察了其对超氧阴离子自由基、过氧化氢的清除活性以及还原能力。结果表明:随着DS的增加,样品清除超氧阴离子的活性增强;而清除过氧化氢的活性以及还原能力的强弱顺序为:OB>OA>OC,这可能是由于O-羧甲基壳聚糖的取代度和对自由基的清除机理不同所致。

O-carboxymethyl chitosan oligosaccharides, having various degrees of substitution （DS were 0.54,0.38 and 0.31, respectively）, were prepared by the etherification of chitosan oligosaccharide. Their antioxidant activities were evaluated by the scavenging of superoxide anion radicals, hydrogen peroxide and determination of reducing power, The resuits indicated that the scavenging effect on superoxide anion increased with the increasing of DS, whereas the orders of their inhibiting efficacy on hydrogen peroxide and reducing power were： OB 〉 OA 〉 OC. That may be related with the differences of substituting degrees and the different scavenging mechanisms against free radicals.