A new 1,3-diketofriedelane triterpene from Salacia verrucosa.

A new 1,3-diketofriedelane triterpene, 21α-hydroxyfriedelane-1,3-dione (1) together with six known friedelane triterpenes, 30-hydroxyfriedelane-1,3-dione (2), friedelane-1,3-dione (3), 26-hydroxyfriedelane-1,3-dione (4), friedelin (5), 21α-hydroxy-D:A-friedo-olean-3-one (6) and kokoonol (7), were isolated from the stems of Salacia verrucosa (Celastraceae). The structures of these triterpenes were characterized by spectroscopic methods (IR, MS and NMR). Compound 3 was strongly cytotoxic against SW620 cell line, whereas compounds 4 and 6 were moderately active against SW620, HepG2 and KATO-III cancer cell lines.