Studies On The Effective Ingredients In Exotesta Of Ginkgo Biloba L. And The Microemulsion Formulation

Large numbers of bioactive substances exist in the exotesta of Ginkgo biloba L. Extractingthese substances from the exotesta of ginkgo biloba is environmentally friendly and with higheconomic values. In order to further develop and utilize resources from exotesta of ginkgo biloba,Ginkgo fruit of three strains of "Ma Ling" numbered for27,33and36in different periods wascollected in this study to measur the fruit fresh weight and the dry weight of the exotesta.Thethree strains of "Ma Ling" numbered for27,33and36were used respectively in this study todetect the effective components contens of ginkgo acid and flavonoids during different growthperiods by using RP-HPLC and spectrophotometer method. In addition, based on the microemulsion structure theory, we systematically studied ginkgolic acid micro emulsion by exploringphysical and chemical properties and using indoor bioassay methods. The results are asfollowing:1. The fruit fresh weight of Gingko biloba L. from the three strains presents the change ofrising gradually during different growth periods. From May20thto July20thwas the rapid growthof the fresh weight from gingko fruit, and then to the mature period. The dry weight changing ofexotesta of Ginkgo biloba L.from the three strains was not consistent. The dry weight changingof exotesta of No.27had been rising, until the mature stable. The dry weight changing of exotestaof No.33and36was only on May20thto June10thin rapid rise, than the dry weight changing ofexotesta of No.36had been in a stable period. The analysis form F test showed that the fruit freshweight from three different strains of "Ma Ling" in different growth periods have significantdifferences (P<0.01).2. The total ginkgo acids content of exotesta of Ginkgo biloba L.from the three strainspresents the change of first rising and then declining during different growth periods. The totalginkgo acids content of exotesta increased gradually first, to be highest on July20th. The contentof total ginkgo acids in three strains of27,33and36reached138.7914mg/g and140.9783mg/gand220.7511mg/g, and then kept stable in October. The analysis form F test showed that thetesta total ginkgo acid contents from three different strains of "Ma Ling" have significantdifferences (P<0.01).3. Significant differences at0.01level were found among C13:0、C15:1、C17:1contents ofexotesta of Ginkgo biloba from the three different strains during different growth periods. Thevariation tendency was consistent with that of the total ginkgo acid contents, both showinghighest on July20th. Among the three strains, C13:0, C15:1, C17:1were highest in the exotestaof ginkgo biloba of No.36, with the maximum levels of48.92811mg/g,106.5389mg/g and41.54108mg/g, respectively.4. Total flavonoid contents of the testa of ginkgo biloba presented a tendency of first risingfollowed by gradually declining in different strains. Total flavonoid contents of No.27and No.33increased gradually first, presented the maximum value at the collection time of July20th and August10th, respectively. By contrast, total flavonoid contents of No.36had a brief decling afterarising to July20th, followed by a gradually decling after arising to August30th. After reaching to20.6887mg/g,17.1633mg/g and12.1159mg/g, the total flavonoid contents of three strainsbegan to decling and kept stable in in October. The analysis form F test showed that the testaflavonoid contents from three different strains of "Ma Ling" have significant differences(P<0.01).5. High significant positive correlation at0.01level occurred between total ginkgo acid andlong-chain phenolic acids in C13:0, C15:1, C17:1contents from exotesta of ginkgo biloba.Ginkgo acids contents and total ginkgo flavone contents had a significant positive correlation,with the correlation coefficient of0.555.6. Ginkgolic acids microemulsion solvent system, cosolvent help surfactant and emulsifiersystem were screened, which were suitable to prepare ginkgolic acid micro emulsion by using theextraction of phenolic acids as raw materials from Ginkgo biloba L. exotesta. A6%ginkgo acidextract microemulsion was successfully made, with the composition of6%of exotesta extracts,25%of emulsifier (DBS-Ca and BY-110-volume ratio1:1.5),25%of solvent and cosolvent(ethanol and n-butyl alcohol volume ratio of1.5:1) and50%of water. The micro emulsionpreparations were qualified by quality testing, with all indexes meeting requirements ofcommodity pesticides.