Preparation Process And Bioactivity Of Effective Components From Testa Of Ginkgo Biloba Seeds

The testa of Ginkgo biloba seeds have the characters of killing bacteria and insects.But the testa have being regarded as the waste in further process of gingko seeds, as there has no appropriate way to use them.Because of poison of the testa to the environment, it has become an urgent problem to the local enterprises and governments of the planting area.The physical and chemical characters of the testa of ginkgo biloba seeds was studied, and an efficient extraction process for separation and purification of hydroginkgoic acid using solvent circumfluence technique was firstly established. This process composed of seven steps:①7 0%Ethanol exteaction at 50℃for 4h×2.②Aether extraction.③5%Sodium carbonate extraction.④5%Sodium hydroxide extraction.⑤Hydrochloric acid neutralization reaction.⑥Lead acetate deposition reaction.⑦Hydrochloric revivification reaction.Finaly the purity of hydroginkgoic acid exceeds 90 % while being detected by HPLC.Further, the influence factors of the ultrasonic extraction process were studied, including the ultrasonic time, the ratio and the concentration of ethanol by orthogonal experimental design.The best combination to extraction of flavonoid was with 80% ethanol and ratio 60:1 for 45min.The best combination to extraction hydroginkgoic acid was with 80%ethanol and ratio 40:1 for 45min,.The distribution of active components in variant parts of the gingko biloba was determined, and the results indicated that hydroginkgoic acid in the testa of ginkgo seeds was higher than in the leaves and the peduncle of fruit.The content of hydroginkgoic acid in the testa was not changed clearly with storage time, which indicate that hydroginkgoic acid is stable under the normal condition. The effects of siphon circumfluence circle to the abstraction efficiency was studied, and the results showed that the shorter circumfluence circle is more efficiency with soxhlet apparatus.The biological activities of the crude extract and pure product from testa was tested, and the result showed that the crude extract strongly inhibited the growth of fungi like Exserohilum tuicicum, Fusarium graminearun and Colletotrichum gloeosporiodes, and also killed green mite and aphis. Hydroginkgoic acid inhibited fungi such as Fusarium graminearun and Colletotrichum gloeosporiodes and killed the lead a high deadly rate to the green mite, aphis and Pieris rapa.This subject comes from the production practice of the ginkgo enterprises, and the result would be provided the basis for further application.