Synthesis and biological activity of novel 3′-trifluoromethyl taxoids

Second generation taxoids possessing a trifluoromethyl moiety in place of the 3′-phenyl group are synthesized by means of the β-Lactam Synthon Method. The in vitro cytotoxicities of these new taxoids are evaluated against several different human cancer cell lines and found to exhibit greatly enhanced activities as compared to those of paclitaxel and docetaxel. The activity enhancement is most remarkable against a drug-resistant breast cancer cell line, MCF7-R, expressing MDR phenotype.