Comparison of Semi-bionic Extraction and Enzymic Treatment for Extraction of Flavonoids from Ginkgo Leaves

Comparison of extraction processes for flavonoids in Ginkgo leaves by semi-bionic extraction and enzymic treatment were investigated using the contents of flavonoids as indices. For enzymic treatment, the leaves were hydrolyzed with enzymes at pH=8.0, 45℃ and each 5g Ginkgo leaves with 4.5mg,enzymes for 2h, followed by extraction at 90℃ with 20 times the weight of alcohol-water solution for 2h 3 times. The extractive yield of total flavonoids from Ginkgo leaves is 6.3468 mg·g-1. For semi-bionic extraction,optimum extraction conditions were determined as follows : extract concentration 80%,temperature 80 ℃, stock ratio 1∶20 (g/mL, mass:volume). The extractive yield of total flavonoids from Ginkgo leaves is 6.4598 mg·g-1.