羧甲基化茯苓多糖的抗氧化性分析

Antioxidant analysis of carboxymethylated Poria cocos

通过溶媒法对碱溶性茯苓多糖进行羧甲基化结构修饰,浓缩干燥后得到白色羧甲基化茯苓多糖固体,对改性后的茯苓多糖进行抗氧化性研究,探究羧甲基化茯苓多糖抗氧化活性与其浓度梯度变化的关系。结果表明:羧甲基化茯苓多糖样品溶液与同浓度的维生素C相比,样品的总抗氧化性及对DPPH自由基清除率明显高于维生素C,但对超氧离子自由基和羟基自由基的清除能力略低于维生素C。其中,样品浓度在1.0g/L时对DPPH自由基清除率最大,为91.74%,比维生素C高出31.34%。样品溶液对超氧阴离子自由基和羟基自由基清除率最大值分别为49.39%和72.62%,对超氧阴离子自由基清除效果明显低于相同浓度的维生素C,二者最大值相差25.97%。修饰后的茯苓多糖样品溶液相比修饰前对三个自由基的最大清除率分别提高了33.91%、52.86%和72.62%,总还原能力也有所提高,羧甲基化结构修饰使茯苓多糖的抗氧化活性明显增强。

The carboxymethylated of alkali soluble Poria cocos polysaccharide was modified by solvent extraction method,and the white carboxymethylated Poria cocos polysaccharide solid was obtained after concentrated and dried.The antioxidant activity of modified Poria cocos polysaccharide was studied.The relationship between antioxidant activity of carboxymethylated Poria cocos polysaccharide and its concentration was investigated.Compared with VC,carboxymethylated Poria cocos polysaccharide solution total antioxidant activity and scavenging acivity of DPPH radical were both significantly higher than VC,but scavenging ability of superoxide radical and hydroxyl radical was slightly lower than VC.At the concentration of 1.0 g/L,the highest DPPH radical scavenging rate was 91.74%which was 31.34%higher than that of VC.The maximum scavenging rate of the sample solution to superoxide anion radical and hydroxyl radical was 49.39%and 72.62%,respectively.The scavenging effect to superoxide anion radical was significantly lower than that of VC in the same concentration,and maximum difference between the two was 25.97%.The maximum scavenging rate of three free radicals of modified Poria cocos sample solution was 33.91%,52.86%and 72.62%higher than that of Poria cocos sample solution,and the total reducing capacity was also improved.The conclusion is that carboxymethylation modification enhanced antioxidant activity of Poria cocos polysaccharide.