Abstract
Semi-preparative high-speed counter-current chromatography (HSCCC) was successfully used for the isolation and purification of flavonoid glycoside from the leaves of Siraitia grosvenori by using a two-phase-solvent system composed of ethyl acetate–n-butanol–water (4:1:5, v/v/v). kaempferol-3,7-O-α-L-dirhamnopyranoside was obtained in one-step separation and less than 5.5 h from 90 mg of crude extract from the S. grosvenori leaves. The chemical structure of this compound was identified by MS, 1H NMR, and 13C NMR. Free radical scavenging activity of kaempferol-3,7-O-α-L-dirhamnopyranoside was also evaluated and the results showed that it had good free radical scavenging activity with its IC50 value being 3.97 mg/ml.
ACKNOWLEDGEMENTS
This study was supported by the National Natural Science Foundation of China (20762001), Guangxi Science Foundation (0832024, 0832080), and Guangxi's Medicine Talented Persons Small Highland Foundation (0808).