Study on extraction process of total flavonoids from RADIX RHIZOMA GLYCYRRHIZAE by ultrasonic-assisted method.

[Objective] To optimize the extraction process of total flavonoids from RADIX RHIZOMA GLYCYRRHIZAE. [Method] Total flavonoids were extracted from RADIX RHIZOMA GLYCYRRHIZAE with ethanol by ultrasonic-assisted method, whose extraction process was optimized by orthogonal test design. [Result] The optimum extraction process was as follows: ethanol concentration of 75%, solid-liquid ratio of 1∶25, ultrasonic power of 350 W and ultrasonic duration of 25 min. Under the above conditions, the extraction rate of total flavonoids reached as high as 1.943%. The influencing order of each factor on extraction rate of polysaccharides was determined to be: ethanol concentrationsolid-liquid ratioultrasonic powerultrasonic duration. [Conclusion] The study could provide a scientific basis for the further exploitation and utilization of RADIX RHIZOMA GLYCYRRHIZAE.