Optimization of extraction process of total flavonoids from Cortex Lycii and its biological activities

To research the optimization of ultrasonic-assisted extraction of total flavonoids from Cortex Lycii and its biological activities. Box-Behnken design experiment was used to optimize the extraction process, and AB-8 macroporous resin was used for purification. Its biological activities were studied by the inhibition rate of α -glucosidase and α - amylase and the scavenging rate of DPPH and ABTS. The optimal extraction parameters of total flavonoids from Cortex Lycii were as follows: the extraction temperature was 63 ℃, the ethanol volume fraction was 71%, the solid–liquid ratio was 28 mL/g, the extraction time was 61 min. Under this optimal condition, the yield of total flavonoids was 1.674 mg/g, which was consistent with the predicted value of 1.637 mg/g, and was 5.85 times higher than that of the traditional water extraction method. The inhibitory rate (IC 50 ) of total flavonoids extract from Cortex Lycii on α -glucosidase was 3 μg/mL and on α -amylase was 5 μg/mL. The scavenging rate (IC 50 ) of DPPH radical was 0.648 mg/mL and the scavenging rate (IC 50 ) of ABTS radical IC 50 was 0.012 mg/mL. The optimized extraction process with response surface design was reliable, which could be used for the extraction of total flavonoids from Cortex Lycii . It has strong hypoglycemic and antioxidant activities and has a good prospect for future utilization and development.