Abstract: Guided by liver protective activity,chromatographic separation technology was applied to the ethyl acetate portion of ethanol extract of Sedum emarginatum Mig.Nine compounds were isolated and identified.heptacosane-triol (1),(3S,5R,6S,9R)-megastigmane-3,9-diol (2),tamarixetin (3),quercetin (4),luteolin (5),isorhamnetin (6),p-coumaric acid (7),β-carotene (8),β-sitosterol (9).Compounds 1-7 are isolated from this species for the first time.Compounds 4-7 all exhibited oxidative damage inhibitory activity which is induced by carbon tetrachloride in normal human hepatocyte L-02 with dose- dependent relationships.It follows that the main effective substances of Sedum emarginatum Mig are flavonoids,and the mechanisms of its hepto-protection effect is related to antioxidation.

Key words: Sedum emarginatum Mig., hepto-protection, antioxidation, chemical constituents