Abstract: On the basis of single-factor test,the ultrasound-assisted extraction process parameters of flavonoids from Eucommia ulmoides staminate flower were optimized by the quadratic general spinning design on ethanol concentration,extraction time and ultrasonic power. The results showed that the optimal parameters are as follows:the ethanol concentration 60%,the extraction time 34 min and the ultrasonic power 320 W. Under these conditions,the actual extraction rate of the flavonoids is 13.13 mg/g,consistent with the prediction value. Among the three factors,the alcohol concentration most significantly affects on the extraction rate,followed by the ultrasonic power and the extraction time,and no interaction exists among them.

Key words:  , Eucommia ulmoides staminate flower； ultrasound-assisted extraction； flavonoids； response surface methodology