Chemical Structures and Hepatoprotective Effects of Constituents from the Leaves of Salacia chinensis

The methanolic extract from the leaves of Salacia chinensis collected in Thailand was found to show a protective effect on D-galactosamine-induced cytotoxicity in primary cultured mouse hepatocytes. From the methanolic extract, eight new glycosides, named foliachinenosides E, F, G, H, and 1, and foliasalaciosides J, K and L, were isolated together with 26 known constituents. The structures of new glycosides were determined on the basis of physicochemical and chemical evidence. In addition, the hepatoprotective effects of the isolated compounds on D-galactosamine-induced cytotoxicity were examined. Among them, lignans, eleutheroside E-2 and 7R,8S-dihydrodehydrodiconiferyl alcohol 4-O-beta-D-glucopyranoside, were found to show the protective effects [inhibition (%) 41.4 +/- 3.6 (p<0.01), 45.5 +/- 2.7 (p<0.01) at 100 mu m, respectively].