3,4-seco-lupane triterpene derivatives with cytotoxic activities from the leaves of Eleutherococcus sessiliflorus.

A new 3,4-seco-lupane triterpene, named sessiligenin (1), along with four known 3,4-seco-lupane triterpene derivatives (chiisanogenin 2, chiisanoside 3, divaroside 4, and sessiliside-A1 5) were isolated from the ethanol extract of the leaves of Eleutherococcus sessiliflorus (Rupr. & Maxim.) S.Y. Hu by silica gel column chromatography, and their structures were determined by spectroscopic data. Furthermore, all these compounds were tested for their cytotoxicities against cancer cell lines HepG2, B16-F10, Lewis and YAC-1, as well as normal cell lines NCTC1469 and HL-7702, and significant cytotoxicities had been found for this new compound (sessiligenin 1) which exhibited much lower cytotoxicities against normal cell lines NCTC1469 and HL-7702. It was deduced that the reduce of glycosyl from the structures of these 3,4-seco-lupane triterpenoids enhanced the cytotoxicities. Furthermore, with the complete removal of glycosyl group and the 11-hydroxyl and 3-carboxyl formed by the opening of the lactone ring, the cytotoxicity increased significantly.