桑叶黄酮的提取及抗氧化研究

Study on extraction and anti-oxidation of flavonoids from Morus aLba L. leaves

考察提取溶剂、提取温度、提取时间、固液比等单因素对桑叶黄酮提取效果的影响,采用正交试验确定最适提取条件,用AB-8型大孔吸附树脂作为层析柱填充料,对桑叶黄酮的提取物进行纯化,并探讨所得黄酮类化合物的抗氧化活性,对不同季节桑叶黄酮含量及抗氧化性进行了比较研究。结果表明:桑叶中黄酮类化合物的最佳提取溶剂是70%乙醇,在固液比1:50、提取时间1.5 h、提取温度80℃的条件下,黄酮得率达3.50%;不同季节桑叶中,春季桑叶的黄酮含量最高,夏季桑叶次之,秋季桑叶黄酮的含量最低,且春季桑叶黄酮抗油脂氧化能力最强,夏、秋桑叶黄酮依次减弱;秋季桑叶黄酮对DPPH自由基的清除率最高,夏、春桑叶黄酮依次减弱,秋、春季之间呈显著性差异。

The extraction method of flavonoids in leaves of Morus aLba L.was studied by using orthotropic test method.The optimum extracting process was put forward,and anti-oxidation property of the extract from the leaves of Morus aLba L.was studied by using the Schaal dry oven method and DPPH·method.The results showed that the optimum extracting solvent was 70% ethanol,and the optimum technic of extracting flavonoid of Morus aLba L.leaves was as follows： solid-liquid ratio 1：50,extraction time 1.5 h,temperature 80℃.Flavonoids in leaves of Morus aLba L.has obvious antioxidant activity with dose-effect dependent,and its antioxidant activity increased distinctly after purification.And its inhibition of lipid oxidati on followed the harvest seasons,i.e.spring summer autumn and the scavenging capacity for free radical DPPH·followed the harvest seasons,i.e.autumn summer spring.