Abstract: The hydrolysis extraction conditions and content determination method of two flavonoid aglycones （quercetin and kaempferol） in Qingqianliu [Cyclocarya paliurus （Bata1.） Iljinskaja] leaves by high-performance liquid chromatography （HPLC） were studied to, provide reference for quality control of Qingqianliu leaves.Using ethanol-hydrochloric acid mixed solution as the solvent, the extraction and hydrolysis conditions were investigated using a combination of single factor and orthogonal experiments;content determination was conducted using Agilent C18 chromatographic column （250 mm × 4.6 mm, 5 μm） as the separation column and acetonitrile-0.1% formic acid aqueous solution （volume ratio 35∶65） as the mobile phase, with a detection wavelength of 370 nm, a column temperature of 30 ℃, and a flow rate of 1.0 mL/min. The results showed that the optimized extraction and hydrolysis conditions were as follows： Ethanol hydrochloric acid （volume ratio 8∶1） was used as the solvent, and the material-to-liquid ratio was 1∶20 each time, with a 90 ℃ constant temperature water bath reflux for 60 min. The injection volume of quercetin and kaempferol showed a good linear relationship, ranging from 0.080 8 to 0.808 7 μg （R²=0.999 7） and from 0.096 4 to 0.964 6 μg （R²=0.999 9）, respectively;the average recovery rate of quercetin was 100.97%, with the relative standard deviation （RSD） of 2.93%. The average recovery rate of kaempferol was 97.25%, and the relative standard deviation was 3.29%. The extraction and hydrolysis process could significantly increase the content of flavonoid glycosides in Qingqianliu leaves;the established detection method was fast, accurate, and had good repeatability, which could provide technical reference for the quality evaluation of Qingqianliu leaves medicinal materials.

Key words: Qingqianliu [Cycloarya paliurus （Bata1.） Iljinskaja] leaves, HPLC, flavonoid aglycone, quercetin, kaempferol