Study On The High Effective Extraction, Separation And Purification Of Flavonoids In Licorice

The genus Glycyrrhiza L. is a herbaceous plant of Papilionoideae belongs to Leguminosae,which is one of the most important traditional Chinese herbs.In China, Glycyrrhiza L. resource is rich and complete variety and distributed widely.It has an important pharmacological action and health function.In this paper, the research focused on extraction and separation process of flavonoids from Glycyrrhiza uralensis Fisch, the optimum condition was found, and the structure was analyzed for providing scientific basis of further exploitation.First, the extraction process of general flavonoids from Glycyrrhiza uralensis Fisch was studied. Ultrasonic-Microwave Synergistic Extraction (UMSE) method was used, and its process was optimized by orthogonal experimental design, the results showed the optimal UMSE extracting conditions were: ratio of material to liquid,1:15(w:v); extracting time, 15 min; extracting temperature, 50℃; ethanol content, 80%,extracting times, 3, The yield of general flavonoids from glycyrrhiza was 98.80%.Besides, Heat Reflux Extraction(HRE) and Ultrasonic-Assistant Extraction(UAE) methods were also used, their conditions are respectively: HRE: extraction time 90min, ratio of material to liquid 1:15, extraction temperature 70℃, ethanol content 80%, extracting times, 3,yield 99.10%; UAE: extraction time 60min, ratio of material to liquid 1:15, extraction temperature 70℃,ethanol content 80%, extracting times, 3,yield 98.19%. Comparing UMSE with HRE and UAE, the result showed that in condition of almost the same yield of flavonoids, the USME method need less extraction time, so the UMSE is an efficient and fast extraction method, and suitable for extracting flavonoids from glycyrrhiza.Second, the ethanol extract of glycyrrhiza was treated by macroporous resin AB-8 and then recrystallization technology was used, then white powder was gained, it contains flavonoids with a purity of over 96% by analysis of colour reaction, HPLC and UV spectrum.Last, composition A which contains much flavonoids was treated by polyamide column chromatography several times, then compoundⅠwas gained, the structure of which is determined by means of UV spectrum, NMR, the structure of it is liquiritin.