Bioactive taxoids from Japanese yew Taxus cuspidata and taxol biosynthesis

A series of new taxoids, named taxuspines A similar to H and J similar to Z (1 similar to 25), have been isolated together with 37 known taxoids (26 similar to 62) including taxol (42) from the Japanese yew Taxus cuspidata Sieb. ct Zucc. These new taxoids possessed various skeletons containing 5/7/6, 6/10/6, 6/5/5/6, 6/8/6, or 6/12-membered ring systems. Among the new taxoids, some non-taxol-type compounds remarkably reduced CaCl2-induced depolymerization of microtubules, or increased cellular accumulation of vincristine in multidrug-resistant tumor cells as potent as verapamil. Here we describe our recent results on the isolation, structure elucidation, and bioactivity of these new and known taxoids as well as recent development of taxol biosynthesis.