薇甘菊叶的总黄酮提取及抑菌活性研究

以总黄酮提取率为考察指标,采用超声波辅助提取薇甘菊叶中的总黄酮,并采用正交设计试验优化薇甘菊叶的总黄酮提取工艺.通过体外抑菌实验,利用打孔法和试管法分别测定了其对金黄色葡萄球菌、大肠杆菌、沙门氏菌、志贺菌这4种常见细菌的抑菌活性和最低抑菌浓度（MIC）.结果表明,叶中总黄酮最佳提取条件为乙醇体积分数50％、料液比1∶30、超声功率50 W、超声时间50 min,此条件下黄酮得率为10.62％;薇甘菊叶的黄酮提取物对金黄色葡萄球菌、大肠杆菌、沙门氏菌、志贺菌均有良好的抑菌活性,其最低抑菌浓度分别为1.562 5、1.562 5、3.125 0、3.125 0 mg/mL（以黄酮质量浓度计）.

Extraction of Total Falconoids from Mikania Micrantha and Study of Antibacterial Activities

With the falconoids extraction rate as index,total flavonoids from Mikania Micrantha leaves were extracted by the ultrasonic assistance method,and the extraction process was optimized by the orthogonal design.Moreover,the in vitro antibacterial activity （inhibition zone diameter） and minimum inhibitory concentration （MIC） of the above product against Staphyloccocus aureus,Escherichia coli,Salmonella and Shigella were identified by the diffusion method and test tube method respectively.The results show that the optimum extracting conditions are as follows：ethanol concentration is 50％,the ratio of material to liquid 1 ∶ 30,ultrasonic power 50 W,and time 50 min,and the extracting rate of leaves is 10.62 ％.Under such conditions,the above extract of flavonoids has good antibacterial activities against Staphyloccocus aureus,Escherichia coli,Salmonella and Shigella,and the MIC is 1.562 5,1.562 5,3.125 0,3.125 0 mg/mL respectively （calculated through the flavonoid quality concentration）.