Canadian Poplar Bud Chemical Composition

The chemical constituents of Populus canadensis Moench.buds were investigated. The result was important for constituents comparison of north temperate zone propolis and poplar buds extract.It's helpful for quality control of propolis and chemical relationship research between propolis and it's plant sources.Fifteen compounds were isolated by chromatographic techniques with different materials,such as silica gel,macroporous resin D101,polyamide gel,sephadex LH-20, etc.Their structures were elucidated on the basis of physicochemical properties, spectral analysis of UV,IR,MS and NMR,and TLC characteristic comparison with standard samples.They were identified asⅠ)pinostrobin;Ⅱ)chrysin;Ⅲ)kaempferol;Ⅳ)apigenin;Ⅴ)isorhamnetin;Ⅵ)isoferulic acid;Ⅶ)quercetin;Ⅷ)3-O-methyl quercetin;Ⅸ)caffeic acid;Ⅹ)galangin-7-glucoside;Ⅺ)chrysin-7-glucoside;Ⅻ) galangin;ⅩⅢ)pinocembrin-5-glucoside;ⅩⅣ)salicin;ⅩⅤ)syringin.The compoundsⅧ,Ⅹ,ⅩⅢandⅩⅤwere isolated from the genus Populus L.for the first time.The advances in research of the chemical relationship between propolis and it's plant sources were summarized.The results were discussed.