A Study On Specialty About Extraction, Separation And Fuction Of Gingko Polysaccharides

Ginkgo{Ginkgo biloba L), also known as white nut,maidenhair tree, is a gymnosperm Ginkgo Ginkgo and is mainly produced in China (Liang Lixing,1988). Leaves, nuts and testa mused has medicinal value, known as the "body is a treasure living fossil"(Zhang Li Jiao, etc.,2009). Ginkgo ginkgo is seeds of tree, due to which the seed coat of white hard shell and it is commonly known as ginkgo. In recent years, research of ginkgo mainly is in ginkgo acid, ginkgo phenol, the ginkgo protein and oil ginkgo but rarely the polysaccharide reports of ginkgo nut. In this study, ginkgo nut as raw material, physical and chemical properties of the ginkgo starch polysaccharides and pasting properties were studied, and the non-starch polysaccharides ginkgo extract, purification, structural identification, lipid-lowering effect and antioxidantdetailed study of the theoretical basis for the research and development of the ginkgo. The main conclusions are as follows:(1) Ginkgo starch polysaccharide extracted from ginkgo nut and its characteristic traits were analyzed, the results showed that:ginkgo starch amylose content is higher, and at around32.1%; Ginkgo nut starch granules is mostly multi-faceted spherical and oval, which molecular size distribution is more uniform and smooth surface of starch granules. Transparency, solubility, expansibility, retrogradation and freeze-thaw stability of ginkgo starch are better than corn but worse than potato; Viscosity of ginkgo starch is between corn and potato, close to potato, twice as much as corn. Compare with potato and corn, the thermostability and anti-aged of ginkgo starch are worse; With the increasing of the concentration of starch milk, the starch viscosity is strengthened and thermostability is weakened. With the increasing of the speed, the starch thermostability and anti-aged are strengthened and viscosity is weakened, the time of gelatinization is shorter and the temperature is lower. The addition of sodium chloride decreases the viscosity and improves the anti-aging and thermostability, makes the peak time later and the pasting temperature higher. The addition of sucrose improves the viscosity, makes the pasting time later. The addition of citric acid decreases the viscosity and thermostability and strengthens the anti-aging.(2) The hot water extraction and the microwave method respectively applied to the extraction of ginkgo non-starch polysaccharides and orthogonal optimize the extraction process, to get the optimum conditions of the two extraction methods. The hot water extraction:solid-liquid ratio to25mL/g, a temperature of90℃and for5h, and2.76%of the the polysaccharides extraction rate under this condition ginkgo nut.Microwave method:Microwave-assisted Extraction of Ginkgo biloba ginkgo polysaccharide optimum conditions:the solid-liquid ratio of40mL/g, microwave power to700W, extraction temperature of50℃and extraction time of5min under this condition ginkgo nut polysaccharide extraction rate of4.87%. As it can be seen, the microwave extraction is low of cost, high efficiency, but the microwave method might have affected in polysaccharide structure.(3) Non-starch polysaccharides of ginkgo nut of the deproteinized, bleaching process, and the process conditions were optimized.The deproteinized process:Comparison of four methods of removing protein of the Sevage law, trichloroacetic acid, hydrochloric acid and enzymes+Sevage law, and selected Papain Stock Sevage method on the basis of single factor test orthogonal test of which was out the papain Stock Sevage of law deproteinized the best conditions:enzyme dosage0.1g, reaction temperature40℃, the hydrolysis time1.5h and the pH of the solution is7Under these conditions, and the protein removal rate of71.2%, and polysaccharideloss rate of15.3%.Bleaching process:decolorization of ginkgo nut polysaccharide by macroporous resin method, and screened out by static tests Decolorization No.1, the D900and DA-201C of three resins orthogonal test, the bleaching conditions by orthogonal test and dynamic assayoptimization, and results show that:Decolorization No.1is a ideal resin of ginkgo nut polysaccharide decolorization. The pigment removal optimal conditions:the pH of the solution is4.5, a temperature of25℃, the speed of the column was1.5mL/min, the concentration of the sample of selection is4mg/mL and the column capacity is2BV conditions under polysaccharide decolorization rate of82.37%, polysaccharides retention rate of79.12%, and protein removal rate of88.39%.(4) Bleaching the polysaccharide after the deproteinized after DEAE-52cellulose column chromatography, and respectively with distilled water,0.1mol/L NaCl,0.3mol/L NaCl,0.5mol/L NaCl elution primarily and then to get GBSP1and GBSP2, two a component, and yield29.7%and37.9%, respectively. GBSP1by the SephadexG-200dextran gel chromatography are further isolated and purified and then distilled water afforded two components GBSP1-1, and GBSP1-2, and purity of79.48%and100%, respectively. Purified ginkgo nut polysaccharide of GBSP1-2after UV absorption spectrum, Sephadex G-200Sephadex chromatography and HPLC validation pure polysaccharide, up to100%purity.(5) Physical and chemical properties show that:the polysaccharide GBSP1-2of ginkgo nut does not contain starch, protein, reducing sugar and so on; solid as a pale yellow powder, no special smell; soluble in water, insoluble in alcohol, ether, acetone and other organic solvents. By high performance liquid chromatography analysis the the ginkgo polysaccharide GBSP1-2single sugar composition:mannose, galactose, glucuronic acid, glucose and galactose. The infrared spectrum of the polysaccharide GBSP1-2of the Ginkgo nut show that ginkgo nut the polysaccharide GBSP1-2is a polysaccharide characteristic absorption peak and speculated that the polysaccharide GBSP1-2is the acidic polysaccharide containing beta-pyran-glycosidic bond.(6) The ginkgo nut NSP lipid-lowering function of the test results show that:ginkgo nut polysaccharides can significantly reduce the weight by the high fat diet mice, liver index can decrease,renal index increased; ginkgo nut polysaccharides can significantly reduced the TC, TG and LDL-C, increased HDL-C of mice, and no significant differences between the high-dose group and positive control group the indicators, indicating that high doses of ginkgo nut polysaccharide with lipid-lowering function for the occurrence of high-hyperlipidemia some preventive effect; ginkgo nut polysaccharides can significantly reduce the atherosclerosis index (AI) and have some preventive effect on coronary heart disease and atherosclerosis hardening.(7) Ginkgo non-starch polysaccharides in vitro antioxidant activity of experimental results show that ginkgo nut polysaccharides on DPPH radical, superoxide and hydroxyl radicals scavenging effect was significant, and increases with the increase of the mass concentration, but Cleareffective as antioxidants Vc.(8) Non-starch polysaccharides of ginkgo nut antioxidant activity in vivo experiment use hyperlipidemia model mice and research the serum and liver protein, SOD, GSH-Px, CAT and MDA changes. The results showed that hyperlipidemia mice can in serum and liver protein, SOD, GSH-Px and CAT decreased, MDA content increased but ginkgo nut polysaccharides can significantly improve the protein in serum and liver SOD GSH-Px and CAT content, decreased serum and liver MDA content, and with good antioxidant.