Oleanane-Type Triterpene Saponins and Cassaine-Type Diterpenoids from Erythrophleum fordii

Phytochemical investigation of the EtOH extract of the leaves of Erythrophleum fordii led to the isolation of two oleanane-type triterpene saponins (1-2) and five cassaine-type diterpenoids (4-8) along with one known methyl 3 beta-hydroxy-erythrosuamate (3). Their structures were established by extensive NMR, as well as ESI-MS analyses and acid hydrolysis. Biological evaluation of compounds 3-8 against five human cancer cell lines revealed that compounds 5-7 exhibited potent cytotoxic activity with IC(50) values ranging from 1.51 to 8.68 mu M.