用多种人癌细胞株以ＭＴＴ试验，体外筛选半边旗抗肿瘤活性成分。结果显示：化合物５Ｆ，６Ｆ，Ａ及半边旗乙醇提取物ＰＳＥ对５种人癌细胞均有不同程度的杀伤作用，且呈明显的剂量依赖关系。其中６Ｆ的活性最强，其次是Ａ，５Ｆ，而化合物４Ｆ和Ｂ对５种细胞均无细胞毒活性。分析它们的构效关系可以推测，αβ亚甲基环戊酮结构是其活性部位，结构中羟基数目和位置的不同可以影响化合物的活性强度。 With a variety of human cancer cell lines to MTT test, in vitro selection Pentecost anti-tumor active ingredients. The results showed that compounds 5F, 6F, A and PSE ethanol extract PSE of 5 kinds of human cancer cells have different degrees of killing effect, and showed a significant dose-dependent manner. Among them, 6F was the most active, followed by A and 5F, while compounds 4F and B showed no cytotoxic activity on the 5 kinds of cells. Analysis of their structure-activity relationship can be speculated that α  β methylenecyclopentanone structure is the active site, the structure of the hydroxyl number and location of different compounds can affect the intensity of activity.