Flavonoids with hepatoprotective activity from the leaves of Cleome viscosa L

One new flavonol glycoside named visconoside C (1), together with seven known flavonol glycosides, quercetin 3-O-β-d-glucopyranoside 7-O-α-l-rhamnopyranoside (2), quercetin 7-O-α-l-rhamnopyranoside (3), astragalin (4), kaempferol 3-O-(4-O-acetyl)-α-l-rhamnopyranoside (5), kaempferol 7-O-α-l-rhamnopyranoside (6), kaempferitrin (7) and kaempferol 3-O-β-d-glucopyranoside 7-O-α-l-rhamnopyranoside (8) were isolated by various chromatography methods from the leaves of Cleome viscosa L. Their structures were elucidated by IR, UV, HR-ESI-MS and NMR (1D & 2D) experiments. The cytotoxicity and hepatoprotective activities using HepG2 human hepatoma cell line of 1 were measured by MTT assay. At the concentration of 25 μM and 50 μM, 1 showed cytotoxic activity against HepG2 cells (cell viability was decreased to 22.2 and 23.0%, respectively, compared with doxorubicin control), while at the concentration of 100 μM, 1 showed hepatoprotective activity against CCl₄-induced hepatotoxicity on HepG2 cells (34.3%, compared with quercetin control).