A Research On Extraction And Preparation Technology Of Flavonoids From Ginkgo Biloba Leaves

Objectives:Ginkgo biloba is a plant whose roots,fruits and leaves can be used as medicines.More than 200 ingredients have been found in it and over 40 kinds of flavonoid are among them.Flavonoid has various effects,such as antioxidation,scavenging free radicals,promote human blood circulation,regulate blood vessels diastolic,reduce blood sugar,increases blood flow and so on.To make gel preparation from Ginkgo biloba extract(Flavonol glycosides)so that it can provide a technical reference for its development and utilization in Cosmetology.Methods:1.Establish the measurement method of the volume of Flavonoid in Ginkgo biloba extract;2.Study on the preparation route of Ginkgo flavone and optimize the ethanol extraction process;3.Study on the preparation technology of Ginkgo biloba extract gel.Results : 1.The measurement method of HPLC of quercetin,kaempferol and isorhamnetin have been established.2.The results show that crushing Ginkgo leaf into powder before the treatment can significantly improve the efficiency of extraction,the most suitable number of extraction is twice,the best alcohol-extraction pH is 9.5 and the perfect laying time of the extract liquid is 48 hours.The best technological parameters by orthogonal experiment are concluded as the following: the ethanol concentration is 75%,the solid-liquid ratio is 1:30,the time of extraction is 2 hours and the extraction temperature is 80 ℃.3.The research of Ginkgo flavone gel preparation shows that the best substrate is Carbomer 940 with an amount of 1%,the pH adjuster is triethanolamine,the amount of humectant glycerol,preservative imidazolidinyl urea is respectively 8% and 0.35%.Conclusions: 1.The preparation process of Ginkgo leaf Flavone in this experiment,the content of total flavonol glycosides in dry powder of Ginkgo leaf extract is 26.5%,in which the contents of quercetin,kaempferide and isorhamnetin are 5.7%,3.5% and 1.4%.The yield of dry powder is 9.3%.The percentage of total flavonol glycosides extraction in Ginkgo leaf is 2.476%,which is higher than 1.08% reported in the present literature.2.The preparation process of Ginkgo flavone gel is simple and easy to operate,the method is suitable for mass production,it provides a theoretical basis for the development of Ginkgo leaf extract gel preparation.