Studies on the antimicrobial active constituents of stem and leaves from Menispermum dahuricum DC.

AbstrcatThe stem and leaves of M.dahuricum DC.were exhaustively extracted with ethanol.The extraction was done with petroleum ether,ethylacetate and n-butanol in turn.The antimicrobial components from various extracts were investigated and found that the components from petroleum ether had high antimicrobial activity on the Penicillium sp.The components from ethylacetate could restrain the Staphylococcus aureus seriously,and have high antimicrobial activity against Candiasp,E.coli and Phytophora capsic.The components from n-butanol had no antimicrobial activity.We derived compound Ⅰ and compound Ⅱ from ethylacetate extract.Compound Ⅰ could restrain the Staphylococcus aureus and Phytophora capsic.Compound Ⅱ had antimicrobial activity on Candiasp and Phytophora capsic.On the basis of spectral data and chemical reaction,Compound Ⅰ was elucidated to be isoquercitrin,which was isolated from the stem and leaves of M.dahuricum DC.for the first time.