Abstract: Response surface methodology (RSM) was used to optimize ultrasonic-assisted extraction for total polyphenols from Agrimonia pilosa Ledeb.based on single-factor experiment.The main factors extraction temperature,liquid-material ratio and ethanol concentration were determined.The relationship between influencing factors and response values was established.The optimum extraction conditions were as follows: the extracting solvent was 71% ethanol,solid-liquid ratio was 1:24,extracting temperature was 60℃,and extracting time was 20 min.Under these conditions,the maximal yield of total polyphenols reached 3.56%,which was well matched with the predicted concent.

Key words: Agrimonia pilosa Ledeb., total polyphenols, ultrasonic-assisted extraction, response surface methodology