A new ursane triterpenoid caffeic acid ester from Crataegus oresbia

A new ursane triterpenoid caffeic acid ester, cratoresbate A, together with seven known ursane triterpenoids (3- O - trans - p -coumaroyltormentic acid, 3- O - cis - p -coumaroyltormentic acid, α-amyrin, ursolic acid, pomolic acid, euscaphic acid, and tormentic acid) were isolated from the twigs and leaves of Crataegus oresbia W. W. Sm. Cratoresbate A showed significant cytotoxicity against HepG2 cells with IC 50 value of 1.9 µmol L −1 .