Study on microwave extraction technology of RADIX PAEONIAE RUBRA coupled with RADIX SCUTELLARIAE.

[Objective] To discuss the microwave extraction technology of paeoniflorin and baicalin from RADIX PAEONIAE RUBRA coupled with RADIX SCUTELLARIAE. [Method] Using ethanol solution as solvent, microwave extraction technology was adopted to extract paeoniflorin and baicalin from RADIX PAEONIAE RUBRA coupled with RADIX SCUTELLARIAE. And the content of paeoniflorin and baicalin was tested by HPLC. Then the effects of microwave power, charging pump frequency, volume fraction of ethanol, solid-liquid ratio and soaking time on the yield of paeoniflorin and baicalin were investigated by means of orthogonal design and single factor test. [Result] The optimal microwave-assisted extraction technology of paeoniflorin and baicalin was soaking time 9 h, microwave power 36 kW, charging pump frequency 9 Hz, volume fraction of ethanol 50%, and solid-liquid ratio 1∶12 (g/ml). The yield of paeoniflorin and baicalin was 1.84% and 2.91% respectively under the above technology, which was higher than that of ultrasonic method and reflux method. [Conclusion] Microwave extraction method is superior to ultrasonic method and reflux method, which has widespread application prospects in extraction of active constituents from Chinese medicinal herbs.