牛奶子树不同部位多糖抗氧化活性比较研究

Comparisons of Antioxidant Activity of the Polysaccharide from Different Parts of Elaeagnus umbellata Thunb.

从牛奶子(Elaeagnus umbellata Thunb.)的叶片、枝条、种子中提取多糖,并研究其抗氧化活性。采用热水提取、Savage法除蛋白、80%乙醇沉淀得其粗多糖。以Vc为对照,用番红花红光度法测定其对羟基自由基的清除作用;用邻苯三酚自氧化法测定其对超氧阴离子的清除作用;用Fe3+还原力法测定其还原能力。结果表明:3个部位所含多糖对羟基自由基、超氧阴离子自由基都可起到有效的清除或抑制作用,其中对羟基自由基清除活性依次为:种子>叶片>枝条>Vc,对超氧阴离子自由基清除活性依次为:种子>Vc>叶片>枝条,3个部位所含多糖都有还原性,但效果都不如硫脲。

Polysaccharide of branches,leaves,and seeds of Elaeagnus umbellata Thunb.were extracted with hot water.Protein was excluded using the savage method,and then concentrated and precipitated with 80% ethanol to obtain the polysaccharide.Antioxidant activity of polysaccharide was evaluated by the efficiency of scavenging the hydroxyl radical and superoxide anion radical and reductive potential,with ascorbic acid used as a positive control.Results showed that the polysaccharide with three parts was effective in removing hydroxyl radical,superoxide free radicals,the scavenging activity on hydroxyl radical from the highest to the lowest was seeds〉leaves〉branches〉Vc,while superoxide removal activity from the highest to the lowest was seeds〉Vc〉leaves〉branches.All of polysaccharides possessed strong reducing power,but the effect was not as Thiourea