Croblongifolin, a new anticancer clerodane from Croton oblongifolius.

A new furoclerodane, croblongifolin, together with one known clerodane, crovatin and one known labdane, nidorellol, were isolated from the stem bark of Croton oblongifolius. Structures were established based on spectroscopic and X-ray analysis. Croblongifolin showed a significant cytotoxicity against various human tumor cell lines including HEP-G2, SW620, CHAGO, KATO3 and BT474.