Optimization of an Extraction and Purification Method of Total Flavonoids from Lycium barbarum Leaves

The content of total flavonoids as a evaluating factor and the extracting method of total flavonoids from Lycium barbarum leaves were investigated with an L9(3⁴) orthogonal experiment.The optimum conditions were alcohol concentration 70%,ultrasonic time 50 min,ratio of liquor and material 30 ∶1,and ultrasonic wave power 250 W.The optimum conditions for purification were: addition of 4 mg/mL of the sample with pH 5.0,elution with 5.0 multiple column volume of 70% ethanol,sample flowing velocity 1 mL/min,and eluting velocity 1 mL/min.The extraction and purification methods were studied using adsorption capacity,desorption capacity,and recovery as the investigation parameters.Results showed that the method was superior to other methods due to its simplicity,low toxicity,and low variation coefficient.