Extraction, Separation, Structural Analysis And Antioxidant Activity Of Polysaccharides From

Malus prunifolia(wild) bovkh, also know as Malus micromalus, kaido crab-apple, belong to the fruit of Rosaceae Pomaceae Malus Catalpa, is native to some Chinese areas such as Fugu of Shaanxi Province, Baode and Hequ of Shanxi Province, Zhungeer of Inner Mongolia and the three provinces border counties. The fruits of Malus prunifolia(Wild) bovkh has a high nutritional value, with the function of soften blood vessels and in addition to fishy and greasy, have a high food value and medicinal value. Domestic researchers have measured the total sugar, total acid, total flavonoids, tannins, vitamin C and trace elements calcium, iron, zinc contained by Malus prunifolia(Wild) bovkh, fats and proteins were also present in it by another literature.Currently, the total flavonoids and polyphenols of Malus prunifolia(wild) bovkh have been reported, but only one literature of polysaccharide studies in domestic, foreign haven’t been reported.So, the study for polysaccharides of Malus prunifolia(wild) bovkh is not very comprehensive and deeply. Therefore, the paper choose Malus prunifolia(Wild) bovkh as material. Study on the process of extraction, the isolation and purification with modern separation techniques to obtain a uniform component polysaccharides. Analyze preliminary structural and in vitro antioxidant activity. The primary contents and conclusions of this paper were as follows:(1)The polysaccharides of Malus prunifolia(wild) bovkh used hot-water extraction method. On the basis of the single-factor experiments, using response surface method to optimize the design of the extraction process, obtain a quadratic regression model equation: D=8.00-0.29A-0.18B+0.33C+0.068AB+0.025AC+0.93BC-1.53A2-0.43B2-0.9C2The optimal extraction conditions for the extraction temperature:86℃, extraction time:4h, solid-liquid ratio:1:28, this optimum process parameters were extracted to obtain sea red berries polysaccharide extraction rate:8.33%.(2)After separation of DEAE-52cellulose anion chromatography column, the polysaccharide of Malus prunifolia(wild) bovkh components available in different grade. Then by SephadexG-100dextran gel column chromatography, further purified to obtain the pure polysaccharide of Malus prunifolia(wild) bovkh component, named MPB-Ⅰ MPB-Ⅱ, MPB-Ⅲ and MPB-Ⅳ. Using specific rotation spectrophotometry identification, combined with high performance liquid chromatography (HPLC) to verify the components are homogeneous polysaccharide.(3)By gas chromatographic (GC) analysis monosaccharide composition of each polysaccharide, the results showed that MPB-Ⅰ are composed of L-arabinose,D-xylose, D-mannose,D-glucose,D-galactose, MPB-Ⅱ are composed of L-rhamnose, D-arabinose, D-mannose and D-galactose, MPB-Ⅲ only contain D-mannose, MPB-Ⅳ are composed of L-arabinose, D-mannose and D-galactose; With the method of HPLC, the molecular weight of MPB-Ⅰ, MPB-Ⅱ, MPB-Ⅲ, MPB-Ⅳ were6.78×105Da,8.23x105Da,3.34×104Da,1.31×106Da.(4)Infrared spectroscopy and nuclear magnetic resonance spectroscopy were used to determine the initial configuration of four kinds of polysaccharides, the results showed that MPB-Ⅰ and MPB-Ⅳ were a kind of pyranose and β-configuration of the glycosidic bond, MPB-Ⅱ, MPB-Ⅲ of a-pyranoside glycosidic bond configuration.(5)Through the test of antioxidant activity of polysaccharides from Malus prunifolia(wild) bovkh, the conclusion was obtained:polysaccharides of Malus prunifolia(wild) bovkh have some ability to scavenge free radicals, and a strong reduction capability, within a certain range of concentrations, the antioxidant activity of crude polysaccharide of Malus prunifolia(wild) bovkh was investigated by using three radicals(hydroxyl radical,superoxide radical and DPPH), the results showed that has scavenging effect. And the performance of DPPH· scavenging is more significant, the scavenging rate was87.12%when the experimental concentration was1mg/mL.