乙酰化黑木耳多糖的制备及其抗氧化活性研究

Study on the Acetylated polysaccharide preparation and oxidation resistance of Auricularia auricular

本实验采用二次回归正交组合设计法优化了乙酰化黑木耳多糖的制备工艺,并对乙酰化前后黑木耳多糖的抗氧化活性进行了比较研究。实验以甲酰胺为溶剂,乙酸酐为酰化试剂,N-溴代琥珀酰亚胺(NBS)为催化剂,采用二次回归正交组合设计法,以反应时间、反应温度、酰化试剂用量和NBS添加量为实验因素,采用羟胺比色法测定乙酰取代度的大小,以乙酰化取代度大小为实验指标,利用SPSS软件进行数据分析。结果表明,酰化试剂用量和NBS添加量对黑木耳多糖乙酰化有显著影响(p<0.05),经过方程运算,得到制备乙酰化黑木耳多糖的最优实验条件为,反应时间3.5 h,反应温度80.0℃,乙酰化试剂用量32.5 m L,NBS添加量为1.0%,在此实验条件下,得到的乙酰化取代度平均值为0.55。通过对原多糖和乙酰化多糖的红外光谱检测,显示乙酰化黑木耳多糖制备成功。抗氧化活性研究结果显示,黑木耳多糖乙酰化改性后清除羟自由基和超氧阴离子自由基的能力有所增加;还原能力也要比原料多糖有所提高。

The preparation conditions of acetylated Auricularia auricular polysaccharide were optimized by combination design of quadratic regression orthogonal,and the antioxidant activity were studied at the same time. In this experiment, amide was used as solvent, acetic anhydride was used as acetylated reagent and N-Bromo succinimide（NBS）was used as catalyst. Indicators for acetylated degree of substitution, and the reaction time, reaction temperature,acetylated reagents and NBS addition were used for investigation of variable factors and by quadratic regression orthogonal combination design method.The final data was analyzed by SPSS software.The results showed that reagent dosage of acetylated and NBS addition of polysaccharide from Auricularia auricular had a significant effect （ p 〈 0.05） on the acetylated polysaccharide preparation.After equation calculations, the preparation optimal acetylated conditions for Auricularia auricular polysaccharide were as. reaction time 3.5 h, reaction temperature 80.0 ℃,acetylating reagent dosage 32.5 mL, NBS addition was 1.0%.Under the experimental conditions,the acetylating of substitution degree average was 0.55. The results of original polysaccharide and acetylating of infrared spectrum detection showed acetylated Auricularia auricular polysaccharide preparation was prepared. Using the optimal conditions for preparation of acetylated Auricularia auricular polysaccharide, the oxidation resistance research showed that the ability of removal hydroxyl free radicals and remove super oxide anion free radical ability were a little improved,and reducing power was also increased