Secondary metabolites from the liverwort Ptilidium pulcherrimum.

A new trinortriterpenoid, diospyrolide acetate (1) and a new diphenylmethane derivative, pulcherrimumin (12), together with ten known pentacyclic triterpenoids (2-11) and four aromatic compounds (13-16), were isolated from the liverwort Ptilidium pulcherrimum. Their structures were established on the basis of extensive analysis of NMR data and by chemical methods. The cytotoxicity of compounds 1-16 was evaluated against the PC3, MDA-MB-231, and Hela cells lines. Ursane triterpenoids 8-10 exhibited moderate cytotoxicity against PC3 cells with IC50 values ranging from 10.1 to 39.7 microM.