Triterpenoids from the rhizomes and roots of Gentiana scabra Bge. and their cytotoxic activities

Phytochemical investigation on the rhizomes and roots of Gentiana scabra (Gentianaceae) led to the isolation of five new triterpenoids (1-5), together with seven known ones (6-12). The structures and absolute configurations of the new compounds were elucidated by spectroscopic data interpretation, ECD calculation and X-ray crystallographic analysis. Noticeably, compound 4 was an uncommon 3,4-seco-pentacyclic triterpenoid in natural products. The in vitro cytotoxic activities of all isolates against human cancer cell lines (HepG2, Hep3B, HCT116, and U87) were measured using MTT assay. Among them, compounds 2 - 9 , 11 , and 12 exhibited anti-proliferative effects against these tumor cell lines.