Two new coumarins from Herpetospermum caudigerum

The ethyl acetate extract from the seeds of Herpetospermum caudigerum was found to show protective effects on carbon tetrachloride (CCl(4)) and thioacetamide (TAA)-induced acute hepatic injuries in mice. From the ethyl acetate extract, two new coumarins, herpetolide A (1) and herpetolide B (2), along with four known compounds, herpetone (3), dehydrodiconiferyl alcohol (4), 2,4-dihydroxypyrimidine (5) and stigmasterol (6) were isolated. The structures of the new coumarins were elucidated on the basis of chemical and physicochemical evidences. Herpetone exhibited protective effects on CCl(4)-induced hepatocyte injury.