(-)-16-Normethyldictyostatin has been made by total synthesis and is a potent antitumor agent in cells expressing wild-type tubulin and in one mutant cell line that is resistant to paclitaxel, but it is much less active than dictyostatin in another paclitaxel-resistant cell line where Val is substituted for Phe270. This provides strong evidence that the C16 methyl group of the dictyostatins is oriented toward Phe270 in the paclitaxel-binding site on beta-tubulin.
(-)-16-去甲基火绒草平素已通过全合成制得,它是一种强有力的抗肿瘤剂,作用于表达野生型微管蛋白的细胞以及一种对
紫杉醇耐药的突变
细胞系,但在另一种
紫杉醇耐药
细胞系中,其活性远低于火绒草平素,这种情况下Val取代了Phe270的位置。这提供了有力的证据,表明火绒草平素中的C16甲基基团在β-微管蛋白的
紫杉醇结合位点上朝向Phe270。