响应面法优化薤白多糖的羧甲基化修饰工艺及抗氧化活性研究

采用氯乙酸法对醇沉法得到的薤白多糖(PAM)和柱层析纯化的3种分级薤白多糖进行羧甲基化修饰,以氯乙酸浓度、反应时间和反应温度为自变量,修饰产物的羧甲基取代度(DS)为响应值,应用响应面设计法确定羧甲基化修饰的最佳条件,用H2O2/Fe2+体系法和邻苯三酚自氧化法测定修饰产物的抗氧化活性.结果表明:薤白多糖氯乙酸法修饰的最佳条件为氯乙酸浓度1.3 mol/L、反应温度63℃、反应时间3.2 h.此条件下羧甲基取代度为0.882.羧甲基化修饰能提高薤白多糖的体外抗氧化活性.

Optimization of Carboxymethylated Modification Technology of Polysaccharides from Allium macrosttemon Bge. and Study on Antioxidative Activity

Total PAM extracted by ethanol precipitation and three hierarchical PAMs extracted by chromatography purified were carboxymethylation modified by chloroacetic acid method. With chloroacetic acid concentration,reaction time and reaction temperature as the independent variables and carboxymethyl substitution degree( DS) of modified product as the response value,the modification conditions were optimized by response surface analysis. The antioxidative activity of modified product was tested by H2O2/ Fe2 +system and pyrogallol oxidation. The results showed that the optimal modification conditions were 1. 3 mol / L of chloroacetic acid,the reaction temperature was 63 ℃ and reaction time was 3. 2 hours. Under these conditions,the obtained DS was 0. 882. Carboxymethylated modification can enhance the antioxidative activity of PAM.