Optimization of Microwave-assisted Extraction of Flavones from Puerariae Using Box-Behnken

The extraction process of total flavones from puerariae by microwave-assisted extraction is studied.Based on single factor test,Box-Behnken Design is applied to research the effects of microwave power,extraction time and liquid-solid ratio on the extraction rate of total flavones.Quadratic regression model equation between the extraction rate of total flavones and the factors are established,and the regression model is significant.The optimal extraction conditions are then determined as follows: 80% ethanol as solvent,the microwave power at 417 W,the extraction time at 10 min and the liquid-solid ratio at 40∶1mL·g-1.In this case,the extraction rate of total flavones from puerariae sample reaches to 4.923 mg·g-1.