Purification and Corresponding Spectroscopic Analysis of Selenium Polysaccharide in Sour Jujube Fruits

The crude polysaccharide was extracted from sour jujube fruits using hot water extraction followed by ethanol precipitation.The content of crude polysaccharide was(92.6±4.72) mg/g by phenol-sulfuric acid assay,and selenium content of the polysaccharide was(17.8±2.05) μg/kg by fluorescence spectrophotometry method.After further purified by DEAE-52 and Sephadex G-75 column chromatography,a white and flocculent polysaccharide was obtained.After hydrolysis with 2M trifluoroacetic acid,TLC plates was detected and high performance anion exchange chromatography with pulsed amperometric detection(HPAEC-PAD) was further analyzed.A comparative study of the two methods showed that the polysaccharide was composed of rhamnose,xylose,arabinose,glucose and galactose with a ratio of 3.21∶8.36∶5.63∶0.96∶1.82.The selenium polysaccharide exhibited typical absorption of polysaccharide characterized by Infrared spectroscopy(IR) spectroscopy;1H NMR and 3C NMR analysis indicated that the structure of selenium polysaccharide was pyranoid glucan with β-glycosidic bond.