| The modernization of Chinese traditional medicine has been an interesting subject in current medicine field. Separation and preparation of the active composition from Chinese traditional medicine by novel modern technology is an important part in the research of the modernization of Chinese traditional medicine. The completed pharmacological researches have expressed that flavonoid compounds in Litchi seed have a pharmacological activity of anti-hepatitis B virus, andα-(methyl lenecyclopropyl)glycine of amino acids in Litchi seed have a pharmacological activity to reduce high blood sugar. However, the research about separation and preparation process of activity compounds in Litchi seed is yet few. So under the guidance of relative pharmacological theories the separation and preparation process of flavonoid compounds and amino acids in Litchi seed were investigated systematically for the first time in this paper, using some novel modern technologies such as physical field-intensified extraction, macroporous adsorption resin, enzyme-membrane method. Some significant results were obtained, and the conditions and parameters for industrial available process were decided. The work in this paper is described as follows:(1) Extraction technology was studied and optimal extraction parameters were determined. Traditional and novel extraction methods such as reflux extraction, hot solvent extraction, physical field-intensified extraction and compound enzyme extraction were investigated to determine the suitable method to extract flavonoid compounds from Litchi seed.The experimental results show that microwave extraction process is the best efficient one with highest selectivity and low energy-consuming. Under these optimum extracting conditions the average yield of flavonoids was 6.86% and the average content of flavonoids in extracts reached 36.7%. It will have wider application in the future. And hot solvent extraction process can run steadily and does not need complex expensive apparatus. It is fit for these factories of Chinese traditional medicine at present. (2) Purification process of flavonoid compounds from Litchi seed was studied. Fristly refined flavonoid product from Litchi seed was prepared by traditional liquid-liquid solvent extract and polyamide purification method, in which the content of flavnoid compounds was 87.9%. Then purification process of flavonoid compounds from Litchi seed by macroporous adsorption resin was investigated for the first time. HPD-300 macroporous adsorption resin was selected and used to purify flavonoid compounds. The optimal conditions were decided and the content of flavonoid compound in purified flavonoid product was 82.2% after being purified.The experimental research indicates that purification process of macroporous adsorption resin have most advantages of simple, green, environment protecting and low-cost. It is suit for industrial production.(3) Three flavoniod compounds with high purity were isolated from Litchi seed by silica-gel column chromatography and identified as Quercetin, (-)-Epicatichin, and 3'-o-methyl centaurin with UV,IR,~1H-NMR,MS instrumental analysis.(4) The antioxidation activities of Litchi seed extract and its flavonoid compounds were studied for the first time. According to the oxidation mechanism, their antioxidation functions were studied from oxidant, chelation and radical-scavenging aspects. The experimental results showed that the main reason for antioxidation activities of flavonoid of Litchi seeds is because flavonoid of Litchi seeds can chelate some transition metal ions and restrain their catalyses and scavenge active radicals. The differences of antioxidation effects of different flavonoid compounds were analyzed from the relations between their molecular structures and their pharmaceutical effects.The anti-hepatitis B virus activities of Litchi seed extracts, purified litchi-seed flavonoid and flavonoid compounds were studied and the experimental results showed that the anti-hepatitis B virus effects and surplus radical-scavenging effects may play an important role in curing of hepatitis B.(5) Extract process of amino acids in Litchi seed was studied by enzyme—membrane method for the first time. Protein of Litchi seed was hydrolysis to amino acids by neutral protease, then enzymatic hydroly-sates were ultrafiltrated by ceramic membrane so that solid particulates, suspended substances and compounds with high molecular weight like protein and polysaccharide in solution were got out off, optimal parameters of enzyme-membrane process were determined at last.Compared to traditional processes, novel enzyme-membrane process does not need lots of acid, alcohol and flocculating agent for extraction and precipitation, so it is an efficient, simple, green, environment friendship and low energy-consume process. Moreover, enzyme-membrane method can help to short the whole process flow because process of precipitation, deacidification and decoloration can be canceled. In a word, enzyme -membrane process is a superior method and is suit for industrial production.Then amino acids from Litchi seed were purified by ion exchange and recrystal method. D001-CC ion-exchange resin was used to exchange and purify amino acids. Amino acid crystal, in which its purity was 94.2%, could be obtained by recrystal method finally.
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