The Extracting Research Of Bioactive Substances From Testa Of Ginkgo Biloba

Ginkgo biloba testa is mainly containing the ginkgo acid, flavonoids, terpene lactones and polysaccharide; Academic community had studied the isolation, identification and pharmacological activities about it. On the basis of the above work, the paper explored the comprehensive extraction of the main active ingredients from Ginkgo biloba testa, and purificated the flavonoids, ginkgo acids and polysaccharides. The main research contents and results were as follows:(1)The paper exploited the combined extraction process of flavonoids, ginkgo acid and polysaccharide from the ginkgo biloba testa, and analysed the best extraction process of the active ingredients. The results showed that: If it extracts ginkgo biloba testa with the petroleum ether, will get the extract mainly containing the ginkgolic acid, twice extraction rate was 98.49%, the purity is 54.6%; Then it extracts flavonoids from the residual solid with 80% ethanol, only once extraction rate was 96.41%, the purity is 7.46%; Finally it extracts the polysaccharide from the last residual solid with water as solvent, leaching under 90?, 120 min, extracting twice, ginkgo extraction yield of polysaccharide was 72.74%, the purity is 24.3%. The repeatability of the extraction of active ingredients is perfect, and the RSD is less than 0.40%.(2)The crude extraction of flavonoids was further purified with the process of water sinking and macroporous resin purification, it would get three kinds of flavonoids, including biflavones, polarity larger flavonoid glycosides and medium polarity flavonol glycosides.Firstly the crude extraction was evaporated and concentrated to dispose of the solvent, with the pH was 4.5~6.0, it could precipitation isolate smaller polarity of the material, which is mainly containing biflavones and ginkgolic acid identified with HPLC and UV. Then the precipitate part was extracted with the petroleum ether to dispose of ginkgolic acid, it could get biflavones that the purity was 76%, yield of 33%. The solvent after concentrated precipitation mainly contained flavonoid glycosides identified with HPLC and UV, separating and purificatiing with the macroporous resin. It would get strong polarity flavonoid glycosides eluted with water and 20% ethanol, and get medium polarity flavonol glycosides eluted with 70% ethanol. The primary studies suggested that the medium polarity flavonol glycosides are similar with ginkgo biloba flavonoids extracts, its content accounts for about 41% of the total flavonoids, and the others are not hydrolysis of flavonoid glycosides.(3)The paper separated and purificated the crude ginkgo acid through silica gel column chromatography.if eluteing with mixed eluent of Petroleum ether- isopropyl alcohol-acetic acid, it would get the ginkgolic acid that the purity was 97.5%.Then the product was identified of its composition and structure with HPLC, UV and IR.(4)The crude polysaccharides were a kind of non-starch polysaccharides, which were after the alcohol sink and separatied with sevage method(N-butyl alcohol: chloroform = 1:4 mixed solvent extraction), and then could get the polysaccharides that the purity was 64%.