Research On Extraction And Separation Technology Of Flavonoids From Ginkgo Biloba

Ginkgo biloba is one of endemic plants in China, accounting of more than 70 percent of total in the world. Its leaves and fruit have high medicinal value. In recent years, domestic and foreign scholars do a lot of research work on Ginkgo biloba extract (GBE), pharmacological experiments show that the main medicinal ingredients are flavonoids. With in depth researching, the technology of extracting the active ingredients has been constantly updating, the general trend is towards increasing active ingredients yield, reducing the harmful components and impurities residues in the drug, reducing environmental pollution etc. Currently, the main method of extracting flavonoids from ginkgo biloba is extracting by using organic solvent, ultrasonic, enzyme, microwave, and supercritical fluid, etc. By comparison, extraction using organic solvent needs simple equipment, can obtain high-yield products, so it is the most widely used method.In this thesis, on the basis of a detailed summary of the current flavonoids extraction and separation methods from Ginkgo biloba, the process of flavonoids extracting, enriching and separating from ginkgo biloba, were studied with the flavonoids extracted by ethanol-solution, GBE refined by macroporous resin. In the process of flavonoids extraction from ginkgo biloba, after investigating the extracting method, the extracting temperature, extracting time, and pH value of extracts, the best extraction process is determined. In the process of flavonoids enrichment and separation of the ginkgo biloba extracts, the nonhazardous method to human being of macroporous resin adsorption process were used to study the effects of absorption and eluent factors such as the concentration and pH value of flavonoids absorption, the amount of macroporous resin used, concentration of eluting solution, etc. then the best absorption process was determined.In this thesis, the flavonoids in ginkgo biloba as the main object, using organic solvent extraction method, the extraction of the ginkgo biloba flavonoids was studied, using macroporous resin and TLC technology to further separation of flavonoids. And the flavonoids products obtained were detected by spectrophotometry. Study of the different methods of separation can open up some new ways for rational and efficient uses of Ginkgo biloba.