Study on Extraction of Total Flavonoids from Licorice with Ultrasonic Assistance and Antioxidant Activity

To optimize the extraction process of total flavonoids from RADIX RHIZOMA GLYCYRRHIZAE and Study on the Antioxidant Activity. Total flavonoids were extracted from RADIX RHIZOMA GLYCYRRHIZAE with ethanol by ultrasonic-assisted method, whose extraction process was optimized by orthogonal test design.The scavenging effect of pumpkin polysaccharide on OH and O2-were studied by salicylic acid and pyrogallic acid method. 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 concentration＞solid-liquid ratio＞ultrasonic power＞ultrasonic duration. When the solution concentration is 1.1296mg/ml, the scavenging rate of crude flavonoids on superoxide radical is 50%.Suggesting that it would be an effctive natural free radical scavenger. The study could provide a scientific basis for the further exploitation and utilization of RADIX RHIZOMA GLYCYRRHIZAE