Synthesis and Biological Evaluation of a New Series of Highly Functionalized 7′-homo-Anhydrovinblastine Derivatives

Sixteen new 7'-homo-anhydrovinblastine derivatives were prepared in one or two steps from vinorelbine by means of an original and regiospecific rearrangement and subsequent diastereoselective reduction. This strategy has allowed fast access to a family of vinca alkaloid derivatives with an enlarged and functionalized ring C'. Their synthesis and biological evaluation are reported. One compound (compound 35) is 1.7 times more active than vinorelbine as a tubulin assembly inhibitor. Moreover, some of these compounds are highly cytotoxic, and two of them are more potent than vinorelbine on HCT116 and K562 cell lines. Molecular modeling studies, carried out with two of the new vinca derivatives, provide useful hints about how a given functionalization introduced at positions 7' and 8' of the C' ring results in improved binding interactions between one of the new derivatives and the interdimer interface when compared to the parent,compound vinblastine.