Bioactive Constituents from Chinese Natural Medicines. XXXI. Hepatoprotective Principles from Sinocrassula indica: Structures of Sinocrassosides A8, A9, A10, A11, and A12

The methanolic extract from the whole plant of Sinocrassula indica (Crassulaceae) was found to show hepatoprotective effect on D-galactosamineinduced cytotoxicity in primary cultured mouse hepatocytes.From the methanolic extract, five new acylated flavonol glycosides, sinocrassosides A 8 (1), A 9 (2), A 10 (3), A 11 (4), and A 12 (5), were isolated together with 25 compounds.The structures of 1-5 were elucidated on the basis of chemical and physicochemical evidence.Among the isolated compounds, sinocrassosides A 1 (6), A 2 (7), and B 2 (14) were found to show potent hepatoprotective effect.Sinocrassula indica (DECHE.)BERGER, a Crassulaceae biennial plant, is distributed on the mountain areas in China (e.g.Yunnan, Guangxi, Sichuan, Guizhou, and Hunan provinces of China).The whole plant of S. indica has been used for the treatment of hepatitis and otitis media in Chinese traditional medicine. 2During the course of our studies on bioactive constituents from Chinese natural medicines, 1,3-25 we found that the methanolic extract of the whole plant of S. indica inhibited the increase in serum glucose levels in both sucrose-and glucose-loaded rats. 3Furthermore, from the methanolic extract, 10 acylated flavonol glycosides, sinocrassosides A 1 -A 7 and B 1 -B 3 (6-15), were isolated together with 11 known flavonoids (16-26), two megastigmanes (27, 28), L-phenylalanine, and guanosine. 3,4As a continuing study on the constituents from S. indica, the methanolic extract of this herbal medicine was found to show hepatoprotective effect on D-galactosamine (D-GalN)-induced cytotoxicity in primary cultured mouse hepatocytes.From the methanolic extract, we additionally isolated five new acylated flavonol glycosides, sinocrassosides A 8 (1), A 9 (2), A 10 (3), A 11 (4), and A 12 (5).This paper deals with the isolation and structure elucidation of 1-5 as well as hepatoprotective activities of the isolated compounds.The methanolic extract from the dried whole plant of S. indica (7.7% from the dried plant) was partitioned into an EtOAc-H 2 O (1:1, v/v) mixture to furnish an EtOAc-soluble fraction (2.5%) and an