[Study on the comparison of polysaccharides in Ginkgo biloba leaves].

OBJECTIVE: To determine the suitable tree's age, tree's sex and gathering seasons for Ginkgo biloba leaves. METHODS: The twelve different polysaccharides were obtained by extracting and precipitating from Ginkgo biloba leaves and to see if there were differences among them. The concentration of Ginkgo biloba leaf polysaccharides with the highest gain ratio will be determined by HPLC. RESULT: The average gain ratio of Ginkgo biloba leaf polysaccharides was 4.29%, among them the gain ratio of 10-years old female Ginkgo biloba leaf collected in the last ten days of September was the highests, its polysaccharides concentration was 61.5% with RSD = 2.5% (n = 6). CONCLUSION: The gain ratios were different in different Ginkgo biloba leaves and the changing rules provide scientific basis for the GAP of medicinal plants.