Tirucallane-type triterpenoids from the fruits of Phellodendron chinense Schneid and their cytotoxic activities.

Eleven triterpenoids were isolated from the fruits of Phellodendron chinense Schneid, and their structures were determined by spectroscopic analysis. The results show that four new tirucallane-type triterpenoids 1, 2, 5, and 6 and seven known compounds 3, 4, 7, 8, 9, 10, and 11 were isolated. Structurally, compound 6 was uncommon; it has a chlorine atom instead of a methyl group at the C-20 position. The cytotoxicities of the compounds was evaluated against the in vitro proliferation of four human tumor cell lines HEL, K562, MDA, and PC3 using adriamycin as the positive control. Compound 1 showed a similar cytotoxicity as the positive control; compounds 3 and 10 showed moderate cytotoxicities compared to the control (P<0.05). This indicates that these compounds have great potential for the development of new antitumor drugs.