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, vicenin-2, lucenin-2, isovitexin 2"-O- rhamnoside, cerarvensin 2"-O-rhamnoside, vitexin 2"-O-rhamnoside, isoorientin 2"-O-rhamnoside, orientin 2"-O-rhamnoside and sapon- arin. In addition, gallic acid, the phenol C-glycosides bergenin and 11-O-galloylbergenin, three flavonol 3-O-rhamnosides and a new C-glycosylflavone identified as mollupentin 2"-O-rhamnoside 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 antihepatotoxic activities against carbon tetrachloride and galactosamine cytotoxicity in primary cultured rat hepatocytes. Structure-activity relationships are discussed.