An Analysis of the Flavonoids in Ginkgo biloba L. Leaves in Pizhou

Objective:To investigate the relationship of the flavonoids in Ginkgo biloba leaves.Methods:The flavonoids in Ginkgo biloba leaves were determined by HPLC-DAD.Results and Conclusion:Following in the train of increase in the tree's age, the concentration of the quercetin and kaempferol declined gradualy. Their relationship of content changed. The content of quercetin is high with two or three years old. The ratio of kaempferol to quercetin in above 4 years old was smaller than 1.