| Being a kind of raw materials both for natural medicines and health products, Polysaccharide has thebroad application prospects and market demand. Zizyphus jujuba in Xinjiang possesses high potentialnutritional value, pharmaceutical usage and the important bioactive activity. Currently, there are fewerstudies on the polysaccharide from Zizyphus jujuba in South Xinjiang. This paper studied on the extractionprocess, macroporous resin purification process, classification and purification, the primary structureidentification and antioxidant activity in vitro of its water-soluble polysaccharide. The results are asfollows:1The water-soluble polysaccharide from Zizyphus jujube were extracted by Box-Behnken surfaceresponse design and determine the optimum conditions in this study: water temperature was90℃, time was140min, solid-liquid ratio was1:25(g/mL); under this conditon, the yield rate of polysaccharide was53.46%.2Optimized the purification process of water-soluble polysaccharides: Nine kinds of macroporousresins were evaluated for their absorption rate and desorption rate of the water-soluble polysaccharides bystatic adsorption-desorption experiments, confirmed AB-8resin as an ideal resin, optimized the totalpolysaccharides purification process parameters of AB-8resin by response surface method. The resultindicated that the optimum purification conditions were sample concentration of0.4mg/mL, samplevolume of30mL, flow rate of2.0mL/min, pH of six, eluent concentration of50%, elution rate of1.5mL/min, eluent amount of3.0mL, the absorption rate and desorption rate of polysaccharides wererespectively91.74%and78.32%after purification, the yield rate of before and after purification were49.67±1.29and65.57±1.75mg/g, respectively.3Refined polysaccharides were separated by DEAE-cellulose DE-32preliminarily, mainly obtainedfive components such as HWP1, HWP2, HWP3, HWP4and HWP5. Further purified to obtain HWP1a,HWP2a, HWP3a, HWP4a and HWP5a by Sephadex G-100column chromatography respectively, thepolysaccharides HWP3a, HWP4a and HWP5a had no characteristic absorption peaks of the nucleic acidand protein at260-280nm by UV spectrum detection. The polysaccharides HWP1a, HWP2a, HWP3a,HWP4a and HWP5a had characteristic absorption peaks of polysaccharides by Infrared detection.4The preliminary study on the primary structure of the purified polysaccharides:(1) thepolysaccharides HWP-1a, HWP-2a, HWP-3a, HWP-4a and HWP-5a had characteristic absorption peaks at3700-3200cm-1,2970-2840cm-1,1420cm-1and1200-1000cm-1, showed that the polysaccharide had ahydroxyl group, a carboxyl group. The deformation vibration absorption peak of β-D-pyranose C-H was at870cm-1.（2） The relative molecular mass of HWP-1a, HWP-2a, HWP-3a, HWP-4a and HWP-5a were226.7kDa,739.2kDa,44.44kDa,115.2kDa and117.4kDa, respectively.（3） HWP-1a and HWP-2a are both composed of five kinds of monosaccharides,mannose,rhamnose, glucose, galactose, arabinose, the molar ratio are2.85:2.14:26.77:1.76:3.28and1.38:4.26:8.18:7.27:3.79, respectively; HWP-3a is composed of six kinds of monosaccharides, mannose,rhamnose, maltose, glucuronic acid, glucose, galactose, arabinose, the molar ratio is1:4.33:15.34:23.18:28.71:27.44; HWP-4a is mainly composed of seven kinds of monosaccharides,mannose, rhamnose, glucuronic acid, maltose, glucuronic acid, glucose, galactose, arabinose,the molar ratiois3.20:3.60:1.93:4.28:8.71:7.21:4.48; HWP-5a is composed of three kinds of monosaccharides, mannose, rhamnose, glucose, the molar ratio is3.05:1.52:30.26.5The antioxidant activity in vitro of Polysaccharide from Zizyphus jujuba Mill.:Scavenging capacityof polysaccharide before and after purification on DPPH, hydroxyl, superoxide anion free radicals,ABTS+radicals and reducing power, chelating ability were determined by Spectrophotometer.Resultsshowed that the polysaccharide from Zizyphus jujuba Mill. Had certain clearance ability on free radicals,and had obvious dose-dependent relationship in the concentration range. |
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