Study on the extraction of total flavonoids from China-hemp leaves

To supply technical basis for further exploiting and utilizing China-hemp leaves, total flavonoids extraction from China- hemp leaves by ultrasonic- assisted extraction (UAE) and ethanol solvent extraction (ESE) were optimized by orthogonal experiment.The results showed that the efficiency of extracting total flavonoids with UAE was higher than that with ESE.The optimized conditions were 60% ethanol, 1∶40 (g ∶ mL, leave:water) , and 10min under ultrasonic conditions.The total flavonoids yield was 3.05%, comparable to that from Ginkgo leaves.UAE was an effective method to extract total flavonoids from China-hemp leaves.