ABSTRACT
AIM To optimize the ultrasound-microwave extraction for total flavonoids from Glycyrrhizae Radix et Rhizoma residue by response surface method.METHODS In addition to the index of extraction rate of total flavonoids for evaluation,the microwave power,extraction time,liquid-soild ratio and ethanol concentration were taken into consideration as influencing factors for the extraction optimization by response surface method on the basis of single factor test.RESULTS The optimal conditions,determined to be 125 W for microwave power,32 min for extraction time,28.4 ∶ 1 for liquid-solid ratio,79％ for ethanol concentration,and 300 W for extraction power,could bring forth a 2.59％ extraction rate of total flavonoids.CONCLUSION This stable and reliable method can be used for extracting total flavonoids from Glycyrrhizae Radix et Rhizoma residue.