Preparative separation of polyphenols from water-soluble fraction of Chinese propolis using macroporous absorptive resin coupled with preparative high performance liquid chromatography

In this study, a preparative separation method was developed for isolation of eleven polyphenols from water-soluble fraction of Chinese propolis using macroporous absorptive resin (MAR) coupled with preparative high performance liquid chromatography (PHPLC). Water-soluble fraction of Chinese propolis was first “prefractioned” using MAR, which yielded four subfractions. The four subfractions were then isolated by PHPLC with an isocratic elution of methanol-water. Finally, eleven polyphenols were purified from Chinese propolis including caffeic acid, ferulic acid, isoferulic acid, 3,4-dimethoxy cinnamic acid, pinobanksin, caffeic acid benzyl ester, caffeic acid phenethyl ester, apigenin, pinocembrin, chrysin and galangin. The purities of the compounds were determined by HPLC and the chemical structures were confirmed by UV and NMR analysis. The method developed was simple, effective, rapid, scalable and economical, and it was a promising basis for large-scale preparation of multiple components from natural products.