Microwave Extraction Technology for Radix Paeoniae Rubra Coupled with Radix Scutellariae

Using ethanol solution as extraction solvent,microwave extraction technology was adopt to extract paeoniflorin and baicalin from Radix Paeoniflorin Rubra coupled with Radix Scutellariae;and the content of paeoniflorin and baicalin was tested by HPLC.Orthogonal design and single factor tests were used to study the effects of microwave power,feeding pump frequency,volume fraction of ethanol,material to solvent ratio and soaking time on the yield of active ingredient.The optimum conditions of microwave extraction were as follows,soaking time before extraction,9 h;microwave power,36 kW;feeding pump frequency,9 Hz;volume fraction of ethanol,50%;material to solvent ratio,1:12.The yield of paeoniflorin and baicalin was 1.84% and 2.91% respectively under these conditions,which was higher than that of ultrasonic method and refluence method.