Isolation, synthesis, and anti-tumor activities of a novel class of podocarpic diterpenes.

A novel unusual 17-carbon diterpenoid, named (+)-7-deoxynimbidiol, was isolated from the stalks of Celastrus hypoleucus (Oliv.) Warb. Its racemate and derivatives were synthesized, and the inhibitory activities of these compounds against four cultured human-tumor cell lines were evaluated. The structure-activity relationship was discussed.