Research On Extraction And Purification Of Flavones Of Ginkgo Leaves

Traditional Chinese Medicine (TCM) has become the popular spot since toxicity and limitation of synthetical drug is recognized gradually. Extraction and purification of TCM was studied in this paper with flavones of ginkgo leaves as its object. China is home of Ginkgo, 70% of which are grown here. Ginkgo leaves is a mixture of some effective agents such as flavones and lactones, which are useful for cure and prevention of heart disease, tumor and caducity, etc., therefore its product has wide market prospect.In this thesis, traditional method as reflux extraction and newly-rising methods as microwave extraction and ultrasonic extraction were researched for extraction of ginkgo flavones and macroporous adsorption resins were applied to purification of ginkgo flavones. Aluminum chloride-spectrophotometer, ultraviolet spectrum (UV) and capillary electrophoresis (CE) were used for analysis of flavones.1) Extraction of ginkgo flavones. Extraction of effective components is a complex process influenced by many factors such as concentration of extraction solvent, temperature and extraction time, thus appropriate conditions are essential to improve extraction efficiency. Here chemometrics was adopted to design experiments and analyze results of experiments to build models, based on results of models, single factor experiments or simple uniform experiments were performed to validate models and find optimal conditions.When reflux extraction method was investigated, a group of L₈(2⁷) orthogonal experiments were first implemented to select from 7 factors and 5 factors of concentration of ethanol, extraction time, temperature, ratio of liquid to solid (L/S) and granularity were chosen for further investigation by a group of U₁₆ (16¹⁶) experiments. SPSS statistic software and applied software developed by our lab were employed to deal with experiment data and develop models, based on which, several simple experiments were done to validate models and get the optimal conditions, that is , concentration of ethanol was 50%, L/S was 30, temperature was 90℃, granularity of powder of ginkgo leaves was 60～80, extraction time was 5h for 3 times, and extraction efficiency was 2.78% under above-mentioned conditions.When new-rising method of microwave extraction was discussed, a group of U₁₆(4⁵)...