Ginkgo Biloba Fermentation Products Bioactivity Detection And Isolation And Optimization Of Fermentation Conditions

Ginkgo biloba also known as the maidenhair tree, is a unique species of tree with no living relatives. The ginkgo is a living fossil, recognizably similar to fossils dating back270million years. Native to China, the tree is widely cultivated and was introduced early to human history. It has various uses in traditional medicine and as a source of food. In recent years, with the deepening of the chemical testing methods and clinical application, preparation technology of Ginkgo biloba, component analysis, pharmacological effects, toxicology experiments and clinical trials have had a breakthrough.Eurotium cristatum, the advantage strains of brick tea, belong to black tea, was the main factors of quality and unique flavor of brick tea."Fa Hua" is the key to the formation of Fu tea with its unique quality by controlling the external condition, making its dominant species-Eurotium cristatum grow and reproduct, forming cleistothecium which is the unique reproductive organs of ascomycetes, which is in result of Fu brick with a unique quality and flavor.This thesis integrated Eurotium cristatum with Ginkgo biloba. L innovatively. Firstly, this study investigated that different fermentation time had remarkably influenced anti-oxidant activity of fermentation, which was compared with Vc. Secondly, the active ingredient was achieved by HPLC and NMR assays. Thirdly, this study gave a comparison of bacteriostatic activity between some portions from fermentation and non-fermentation. Fourthly, this study optimized fermentation conditions with oxygen free radical clearance rate as index.1. Compare antioxidative activity of Ginkgo biloba fermentation liquid ethyl acetate extract under different fermentation time. Method:The activated Eurotium cristatum was inoculated into liquid medium, incubation time were4,7,11,14d respectively. The ethyl acetate extract of Ginkgo biloba aqueous extract was treated as control. E. cristatum and some residual impurities were filtrated to harvest clear fermentation liquor, and extracted by solvent extractions. Antioxidation of ethyl acetate extract was evaluated by1,1-Diphenyl-2-picrylhydrazyl(DPPH),2,2’-Azinobis-(3-ethylbenzthiazoline-6-sulphonate)(A BTS) and ferric reducing antioxidant power (FRAP) assays. Compare the different activities around fermentation time. Result:All above extracts showed different antioxidant activities, moreover,11d extracts displayed the best activity:DPPH IC50105.7mg·L-1; ABTS IC5083.6mg·L-1, which was close to Vc and the results of absorbance in FRAP test were quite consistent. Conclusion:Antioxidative composition accumulated in Ginkgo biloba fermentation liquor was largest at11d fermentation time.2. A further study involved confirmed that when fermentation progressed for11days, a new compound was produced in the ethyl acetate portion by HPLC and NMR, which was Caffeine.3. Investigate antimicrobial activity of the semipurified fractions between Ginkgo biloba leaves fermentation and un-fermentation. Method:The activated Eurotium cristatum was inoculated into Ginkgo biloba leaves liquid medium, and the achieved fermentation liquid was fractionated by solvent partition using petroleum ether and ethyl acetate, meanwhile, un-fermentation was also extracted by same reagents. The different fractions were used for bacteriostasis experiment. The unfermented ethyl acetate fraction was conducted with MIC test. The bacteria were Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Bacillus cereus. Result:The ethyl acetate extract of Ginkgo biloba leaves un-fermentation liquid showed antimicrobial activity against tested mold, but it was not relevant to the concentration of extract. The MIC of the ethyl acetate extract of un-fermentation was2.5、2.5、5.0、10.0g/mol. E. coli, S. aureus, B. subtilits and B. cereus. Conclusion:There was certain bateriostasis effect of ethyl acetate extract of Ginkgo biloba leaves fermentation and unfermentation on B. subtilits, S. aureus, B. cereus and E. coli, but un-fermentation part was significant. There was no significant difference between the petroleum ether extracts of fermentation and un-fermentation. It confirmed that most of components of bacteriostasis were soluble in ethyl acetate. The decrease of bacteriostatic activity was primarily the result of microbial metabolism.4. Optimized fermentation conditions with oxygen free radical clearance rate as index was performed, which means it can be used for further study on the progress detail.