Optimization of ultrasonic assisted extraction of oleanolic acid from achyranthes by response surface methodology

Oleanolic acid was extracted from achyranthes root by ultrasonic assisted extraction. The effects of ethanol concentration,solid- liquid ratio,and extraction time on the extraction yield of oleanolic acid were investigated.The extraction technology was optimized by response surface methodology. The results showed that the optimal extraction conditions of oleanolic acid were as follows: ethanol concentration was 70%,extraction time was 20 min,and solid- liquid ratio was 1 ∶20. Under above conditions,the extraction yield of oleanolic acid reached11.14 mg / g.