牡丹多糖的提取及其对自由基和亚硝酸根离子的清除作用

为探讨牡丹多糖抗氧化及其清除亚硝酸根离子的能力,对牡丹根进行脱脂、去蛋白等操作,建立了牡丹多糖的提取、纯化工艺,同时测定牡丹根中主要物质组成;通过检测不同质量浓度多糖溶液对DPPH自由基、O_2·和NO_2的清除率,评价牡丹多糖清除自由基和亚硝酸根离子的活性。结果表明,牡丹根的物质组成大致为:粗脂肪含量为6%,蛋白质含量为12%,多糖含量较为丰富,约为29%。确定了制备牡丹多糖的去蛋白最佳方案为:Sevage试剂中氯仿与正丁醇体积比为3∶1,多糖提取液与Sevage试剂添加量体积比为4∶1。牡丹多糖对2种自由基和NO_2均具有不同程度的清除能力,随着多糖质量浓度的逐渐增大,清除率变化趋势表现为先急剧增大,再缓慢升高,最后趋于稳定。对DPPH自由基、O_2·和NO_2达到较好清除效果的多糖质量浓度分别为2.5、2.5、1.0 g/L。牡丹多糖是一种良好的天然抗氧化剂。

Extraction of Polysaccharide from Peony and Its Scavenging Effects on Free Radicals and Nitrite Ion

In order to discuss the antioxidant capacities and the ability to remove nitrite ion of peony polysaccharide,degreasing and deprotein operations for root were taken,and the extraction and purification process of peony polysaccharides were established.At the same time,the contents of crude fat,protein and polysaccharide in peony root were determined.The scavenging rates of DPPH free radical,O2-· and NO2-were detected by different mass concentrations of polysaccharide,and the scavenging activities of polysaccharides were evaluated.The results showed that the contents of crude fat,protein and polysaccharide were 6％,12％,29％ separately,and the content of polysaccharide was more abundant.The best solution for preparation of peony polysaccharides was as follows:the volume ratio of chloroform and butanol in Sevage reagent was 3∶ 1,and the volume ratio of polysaccharide extract and Sevage reagent was 4∶ 1.Peony polysaccharides had various degrees of scavenging capacity for two kinds of free radicals and O2-·.With the increasing of the mass concentration of polysaccharides,the change tendency of the scavenging rates showed a sharp increase at first,and then increased slowly,and finally tended to balance.The optimum polysaccharide concentrations to eliminate DPPH free radical,O2-· and NO2-were 2.5 g/L,2.5 g/L and 1.0 g/L,respectively.It is considered that the peony polysaccharide is a kind of good natural antioxidant.