In order to develop new generation of taxol like anticancer agents with fewer side effects, improved activity, superior
pharmacological properties and broad antitumor spectrum, along with structure activity relationship study, a series of new taxol
derivatives are to be synthesized starting from sinenxan A a biosynthetic taxane. Eight new 14β side chain taxol derivatives with 4 OH and 4 Ac were synthesized in 5 and 6 steps from semisynthetic taxoid intermediate 7, respectively. These included taxol derivatives modified at C 2 position with benzoate, m Cl benzoate, valerate and phenylacetate. All target compounds together with two other 14β side chain taxol derivatives were tested in a microtubule assembly assay, and in an in vitro
cytotoxicity assay (KB, A2780, HCT 8 cell line). All compounds had no effect in the microtubule assembly assay at 10 μmol·L -1 . Most of them showed marginal activity in the in vitro cytotoxicity. The structure activity relationship was different from taxol derivatives. 2 Aliphatic ester displayed similar activity to 2 aromatic ester, which indicated that the aromatic group at C 2 position was not important for cytotoxicity. Comparing among themselves, 4 OH deravitives possessed stronger activity than 4 Ac.