Abstract: The preparation of flavonoid aglycone from the extract of Eucommia ulmoides Oliv.leaves was studied using acid hydrolysis.The effects of solid-liquid ratio, hydrolysis temperature,hydrolysis time and concentration of hydrochloric acid were investigated by single factor and orthogonal experiments.Based on the optimized condition,the two-step enrichment technology of flavonoid aglycones was studied.The results indicated that the optimal conditions were temperature 80 ℃,hydrolysis for 3 h,6 mol/L of hydrochloric acid,when the solidliquid ratio was 2:1 (mg/mL).Under this condition,the contents of flavonoid aglycones reached to 2.512%.The purity of flavonoid aglycones increased to 12.87% after static adsorption by polyamide resin.Finally,the purity of flavonoids glycosides can reach up to 63.19% through the twostep of enriching by polyamide resin.

Key words: Eucommia ulmoides Oliv.leaves, flavonoid aglycone, hydrolyzing, polyamide, enriching