Analysis of flavonoid aglycons in Rhododendron of Sichuan Liangshan

An aqueous solution of the extracts from Rhododendron leaves from Sichuan Liangshan was extracted with solvents of increasing polarity, petroleum ether, ethyl ether, ethyl acetate and butanol. The main flavonoid aglycons extracted into the ethyl ether phase are the subject of this study. The flavonoid aglycons-mycetin, quercetin, kaempferol and farrerol, were separated and identified by thin layer chromatography (TLC), high performance liquid chromatography (HPLC) and liquid chromatography/mass spectrometer/mass spectrometer (LC/MS/MS). A simple and rapid HPLC method was developed for quantitative determination of quercetin and kaempferol in Rhododendron leaves, ethanol extracts and Jinjuan oral liquid drug (Liquor Jinjuan). The analysis of quercetin is useful for quality control of medicinal materials and Liquor Jinjuan products.