中文摘要：

以青钱柳多糖为原料,使用乙酸酐法制备得到乙酰化青钱柳多糖样品。以乙酰化多糖取代度为评价指标,采用正交试验考察乙酸酐-多糖比例、反应时间、反应温度对乙酰化修饰的影响。在此基础上,选择取代度为0.681的乙酰化多糖样品进行1,1-二苯基-2-三硝基苯肼（1,1-dipHenyl-2-picrylhydrazyl,DPPH）自由基清除实验。结果表明,青钱柳多糖乙酰化最优反应条件为：m（多糖）∶V（乙酸酐）=1∶60、反应时间2 h、反应温度40℃,同时,乙酰化修饰可以显著提高青钱柳多糖的DPPH自由基清除活性,乙酰化修饰可作为青钱柳多糖改性的方法之一,为青钱柳资源的进一步开发利用提供新的方向。

英文摘要：

Acetylated polysaccharides from Cyclocarya paliurus were prepared by using acetic anhydride method. An orthogonal array design was used to investigate the effects of ratio between acetic anhydride and polysaccharids, reaction temperature and reaction time on the efficiency of acetylated modification as evaluated by degree of substitution（DS）. The antioxidant activity of acetylated polysaccharide（DS = 0.681） was investigated by DPPH radical scavenging capacity. The optimal conditions for acetylated modification were determined as 1：60, 2 h and 40 ℃ for ratio between acetic anhydride and polysaccharids, reaction time and reaction temperature, respectively. The results indicated that acetylated modification could enhance the antioxidant activity of Cyclocarya paliurus polysaccharides significantly. In conclusion, acetylation could be considered as an efficient method for the modification of Cyclocarya paliurus polysaccharides which provides a new direction for the development and utilization of Cyclocarya paliurus.