Antihepatotoxic C-glycosylflavones from the leaves of Allophyllus edulis var. edulis and gracilis.

From the leaves of Allophyllus edulis var. edulis and Allophyllus edulis var. gracilis nine C-glycosylflavones have been isolated and identified as schaftoside (8), vicenin-2 (9), lucenin-2 (10), isovitexin 2"-O-rhamnoside (11), cerarvensin 2"-O-rhamnoside (12), vitexin 2"-O-rhamnoside (13), isoorientin 2"-O-rhamnoside (15), orientin 2"-O-rhamnoside (16) and saponarin (17). In addition, gallic acid (2), the phenol C-glycosides bergenin (3) and 11-O-galloylbergenin (4), three flavonol 3-O-rhamnosides and a new C-glycosylflavone identified as mollupentin 2"-O-rhamnoside (14) were obtained from the leaves of Allophyllus edulis var. edulis. Their structures were elucidated on the basis of chemical and spectral data. For the first time the C-glycosylflavones were found to have remarkable anti-hepatotoxic activities against CCl4 and galactosamine cytotoxicity in primary cultured rat hepatocytes. Structure-activity relationships are discussed.