薇甘菊总黄酮的提取及清除羟自由基活性的测定

Ultrasonic-assisted Extraction and Radical Scavenging Activity of Total Flavanoids from Different Parts of Mikania micrantha

采用超声波辅助法对薇甘菊(Mikania micrantha)的根、茎、叶及花等器官中的总黄酮分别进行提取,优化提取工艺条件,并测试提取液对羟自由基(·OH)的清除作用。结果表明:根总黄酮的最佳提取工艺条件为50%乙醇溶液、固液比1:25、超声波功率200W;茎总黄酮的最佳提取工艺条件为50%乙醇、固液比1:20、超声波功率500W;叶总黄酮的最佳提取工艺条件为90%乙醇、固液比1:20、超声波功率500W;花总黄酮的最佳提取工艺条件为70%乙醇溶液、固液比1:25、超声波功率200W;薇甘菊根、茎、叶、花的总黄酮平均百分含量分别为3.25%、0.59%、0.88%、2.69%;在设置的4个质量浓度梯度下,薇甘菊根、茎、叶和花的总黄酮提取液对对羟自由基的清除效果与其质量浓度呈正相关,样品质量浓度为1.32mg/mL时,其清除率分别为33.86%、32.58%、38.79%、21.84%,但与相同质量浓度的常用抗氧化剂BHT相比,仍存在一定差异。

The optimal procedures for extracting total flavonoids from roots,stems,leaves and flowers of Mikania micrantha L.under the assistance of ultrasonic were studied using orthogonal array design.Besides,total flavonoids extracted were tested for hydroxyl free radical scavenging activity.Results showed that the optimal values of crucial technological parameters including ethanol concentration,solid/liquid ratio and ultrasonic working power were 50%,1：25 and 200 W for extraction of total flavonoids from roots,50%,1：20 and 500 W for extraction of total flavonoids from stems,90%,1：20 and 500 W for extraction of total flavonoids from leaves,and 70%,1：25 and 200 W for extraction of total flavonoids from Mikania micrantha L.flowers.There was a positive correlation between hydroxyl radical scavenging activity and concentration of total flavonoids from roots,stems,leaves and flowers of Mikania micrantha L.observed at four experimental levels,and the hydroxyl radical scavenging rates at the concentration level of 1.32 mg/mL were 33.86%,32.58%,38.79% and 21.84%,respectively,lower than that of BHT,a common antioxidant.Thus,Mikania micrantha L.,an invasive weed,has a certain potential for exploitation and utilization due to its short growth period and abundance.