Optimization of microwave extraction of flavones in Herba Dracocephali Tangutici using the response surface method

Objective: To investigate the optimal extraction conditions of flavones from Herba Dracocephali Tangutici.Methods: Herba Dracocephali Tangutici as the raw material. Flavones were extracted by different ways such as Oscillatio,ultrasonic and microwave,and the extraction effects were compared. The results indicated that microwave extraction had the advantage of higher efficiency.Four extraction parameters including microwave time,microwave temperature,ethanol concentration and liquid / material ratio were optimized using response surface methodology based on single factor experiments for achieving maximum flavones extraction rate. Results: Results showed that these optimal extraction conditions were as follows: microwave time of 7min,microwave temperature of59℃,ethanol concentration of 27%,and liquid / material ratio of 25 ∶ 1m L / g. Under those conditions the actual yield rate of flavones was 29.68%,and the relative error between the predicted yield 29.65% was 0.1%. Conclusion: The results demonstrated that this method was feasible,and provided reference data for the extraction of flavones from Herba Dracocephali Tangutici.