Biosynthesis Of Pharmacological Second Metabolites As Well As Effects Of Culture On Them And Leaf Yield In Ginkgo Biloba L.

Biosynthesis of Pharmacological second metabolites as well as effects of culture on them and leaf yied in Ginkgo biloba L.Leng pingsheng (Botany)directed by Pro. Jiang xiangning, Pro. Wang TianhuaBiosynthesis and accumulation of flavonoid and terpene as well as effect of culture on them and leaf yield of Ginkgo biloba L were studied with field trials and chemical analysis, experimental results shown:1. flavonoid compound were present in leaves, their content in spring was higher than in summer and actumn; terpene compound content were in the order:bud>leaf>root>stem, phenom>xylem, terpene content in leaf were the lowest in spring and gradually increased until a maximum in late summer or early autumn was reached, thereafter declined, whereas one of stem and root in winter were relatively higher than in spring, leaves were rich in bilobalide, while root and stem in ginkgoblide, terpene content in leaves of Ginkgo biloba seedling were higher than of mature tree by 40~60%.2. summer leave-picking increased leaf yeld by near 2/3, however, had negative effect on ginkgo biloba tree canopy growth next year,2 leave-picking in 1 year was proposed only under good water,nutrients supply after community canopy appearing . fall leave-picking should be proccsed at the end of September , which based on balance between terpene content season's vatiation and the depletion of carbonhydrate reserves and leaf growth caused by fall defoliation.3. VAhk N and P fertilier enhanced obviously foliar Nn P contens, and improved terpene biosynthesis, whereas drought stress decreased foliar terpene content with low water potential and photosynthetic rate , though VAM may lighten the negative effects, however, water deficit almost had little action on flavonoid biosynthesis.Terpene biosynthesis was influenced by light intensity and quality. Some seedlings sprayed by 0. 2% CCC, their leaves, stem and root were higher than contrast by 111. 9%,24. 3%and 31. 5% in Terpene content, 122. 5%, 194. 5% andl27. 1% in bilobalide seperately.In addition, a method has been developed for the qualitative and quantitative analysis of ginkgolide and bilobalide .Components were extracted from Ginkgo biloba leaves with 20% methanol in water, the extracts were purified by means of silica gel columns with toluene-acetone eluation. The trimethylsilylated ginkgolideA, B and bilobalide were determinated by gas chromatography with flame-ionization detector anddentified by a tetrapolar mass spectrometer detector with autharized chemicals. The recovery of the method for bilobalide and ginkgolide A, B were 93. 01%, 96. 32%, 94. 68%, RSD 5. 75%, 3. 88%and 4. 23% respectively.