Studies On Contents Of Phenolic Acids In Leaves And Their Change Characters In Male Plants Of Ginkgo Biloba L.

The leaf of Ginkgo, which contains a variety of active ingredients for human's health, has been developed into an important industry. Especially, the leaf of male plant of Ginkgo has an important development value. The phenolic acids in leaf of Ginkgo, the ramifications of 6-alkyl- or 6-enyl-salicylate with a biological toxicity,have the effects of anti-inflammatory,anti anaphylaxis,antibacteria, disease and pest control, and are the restriction components in EGB(Extract of Ginkgo biloba)used to prevent and treat cardiovascular and cerebrovascular disease. China, is the greatest country producing and exporting the Ginkgo leaf and EGB, needs to promote the product quality of raw materials for processing EGB and to reseach the higher effective techniques and methods for extraction and separation of phenolic acids in leaf of Ginkgo. In this study, the leaves, were sampled from the different types of branch in 9 male plants growing uniformly in Ginkgo germplasm garden of Yangzhou University at different seasons in 2008 and 2009, and were tested at some relative indices such as the leaf area, leaf thickness and SLW etc. respectively, then, were used to determine the contents of Ginkgolic acid(C15∶1), Ginkgolinic acid(C13∶0),hydroginkgolic acid(C15∶0) by UV and HPLC after extraction by the optimal treatment combination of alcoholic concentrations, feed-liquid rate, temperature, time with ultrasonic wave, and extraction,adsorption and purification etc., in order to make definite in the change characters of contents of Ginkgolic acid, Ginkgolinic acid, hydroginkgolic acid in the leaves of male plants in Ginkgo, and the higher effective separate techniques of Ginkgo phenolic acids, and select the Ginkgo male plants with a lower contents of phenolic acids in leaves.The main results made in this experiment show as follows:1,After experiment which determine the contents of Ginkgolic acid, Ginkgolinic acid,hydroginkgolic acid by orthogonal design ,we decide the best efficient extracting combination including alcohol of 80%,ratio of 1 sample to 7 liquids ,supersonic extracting time of 60 min ,temperature of 60℃and extracting time of twice (A1B2C2). Combination with other treatment, the differences in extraction efficiency achieve significant or very significant.2,The content of Ginkgo acid in the leaves of male plant detected by UV is 1.6 times higher than the content of Ginkgolinic acid ; hydroginkgolic acid detected by HPLC, the correlation coefficient between the result of them is 0.9191**,0.9225** , reached a significant leve. After extracting Ginkgolic acid Ginkgolinic acid and hydroginkgolic acid in the use of production, we can use the simply UV to detect the content which can predict the level of phenolic content in the products of Ginkgo-leaves.3,The content correlation coefficients of Ginkgolic acid-Ginkgolinic acid in the leaf of male plant of Ginkgo is 0.9787** , that of Ginkgolic acid- hydroginkgolic acid is 0.9191**,and for Ginkgolinic acid-hydroginkgolic acid in the leaf of male plant of Ginkgo is 0.8325**, which have reached a highly significant level of difference. The content of Ginkgolic acid, Ginkgolinic acid and hydroginkgolic acid in the leaf of male plant of Ginkgo varied from June the 15th to November the 15th which we divided into 9 time groups, the content of the three acid reached to the highest level in June the 15th and September the 15th, the lowest level appeared in August the 1st and August the 15th, compared to other times of the period, it has reached a highly significant level of difference, which indicate that the three acid changed in line.4,The ratio of the content of Ginkgolic acid; Ginkgolinic acid ; hydroginkgolic acid between long and short branches in Ginkgo male plant is 1:1.004,1:1.005 and 1:1.001, respectively, which represents the content of phenolic acids in long branches is lower than that in short branches. 5,The correlation coefficient between the content of phenolic acids and leave area, between the content of phenolic acids and leave thickness in the male plant Ginkgo-leaves is -0.72627** and -0.65851** separately. The bigger of the leave area and leave thickness, the lower of the content of phenolic acids substance.6,The correlation coefficient between the content of phenolic acids and the total flavonoid glycoside in the male plant Ginkgo-leaves is -0.67573**,which represent the higer of the content of flavonoid glycoside in leaves the lower of the content of phenolic acids. Selecting the high content of flavonoid glycoside in Ginkgo biloba product marks its acid content of Ginkgo biloba are relatively low;7,According to the analysis of the different content of Ginkgolic acid , Ginkgolinic acid and hydroginkgolic acid in the leaves of male plant of Ginkgo in different period and the relative analysis of the content of flavonoid glycosides ,we get the result that the leave-collecting time of male plant of Ginkgo should be early in August or in mid-August in this research Region, the Ginkgolic acid , Ginkgolinic acid and hydroginkgolic acid contents of which time was sepearately 1.3817%,0.5361% and 0.3577% ,and the flavonoid glycoside contents was 1.7231%.8,In this experiment ,the content of Ginkgolic acid , Ginkgolinic acid and hydroginkgolic acid are significantly different in the 9 texted leaves of male plant of Ginkgo .The acid content of 1- 3is 1.4040% ,which is not only lower than average but also lower by 4.3875ug/g ,this can provide a further experiment research for low-acid male plant in order to determine the best low-acid male plant of Gingko.The above results provides an important theoretical basis ,the material basis and technological support for screening ,optimal allocation of the germplasm resources ,for efficient extraction of phenolic compounds in the production of Ginkgo biloba EGB ,for promoting foreign exchange income about the products of Ginkgo biloba and EGB.