Objective: To separate and identify the active flavonoids from Beijing Propolis.
Method: The flavonoids were isolated by column chromatography with silica gel and polyamide, purified with Sephadex LH-20, and elucidated on the basis of NMR, MS, UV, IR and CD spectra.
Result: Six kinds of flavonoids were obtained and elucidated as I: pinostrobin, 5-hydroxy-7-methoxy-flavanone; II: pinocembrin, 5, 7-dihydroxy-flavanone; III: tectochrysin, 5-hydroxy-7-methoxy-flavone; IV: chrysin, 5, 7-dihydroxy-flavone; V: izalpinin, 5-hydroxy-7-methoxy-flavonol and VI: galangin, 5, 7-dihydroxy-flavonol.
Conclusion: Compounds I, II, III and V were found for the first time from Beijing Propolis.