Study on chemical constituents of Petasites japonicus

Objective To isolate and identify the chemical constituents in the rhizome of the Petasites japonicus.Methods Dried rhizome of Petasites japonicus were subjected to extraction with EtOH,and the chemical constituents in the extract were isolated and their structures were identified by physicochemical properties and spectral analysis.Results Five compounds were obtained and identified from the rhizome of Petasites japonicus,inlcuding as β-sitoterol(Ⅰ),ergosterol(Ⅱ),bakkenolide-B(Ⅲ),bakkenolide-D(Ⅳ)and furanofukinol(Ⅴ).Conclusion Compound(Ⅱ)has been obtained from Petasites japonicus for the first time.