Study on the Purification and IR Spectroscopy of Se-polysaccharides in Selenium-enriched Flammulina Velutipes

The separation and purification of Se-polysaccharides in the fruit body of Se-enriched Flammulina Velutipes were studied.The contents of polysaccharides and Se in Se-polysaccharides were determined by phenyl-sulfuric acid method and ICP-MS,respectively.Under optimized conditions(80 ℃ extraction temperature,3 h extraction time,1 ∶50 sample to water volume) the amount of polysaccharides and selenium were found to be 12.48% and 7.97 μg/g,respectively.After purifying with Sephadex G-100 column,the refined polysaccharides were characterized by IR spectroscopy.The results showed that the water-soluble polysaccharides were pyranopolysaccharide linked by β-glycosidic.The structure of water-soluble polyaccharides was similar to that of common polysaccharides,whereas the structure of pyranopolysaccharide linked by β-glycosidic was altered due to the formation of selenate ester in alkali-soluble Se-polysaccharides.This further demonstrated that Se participated in the synthesis of Se-polysaccharides during the cultivation of Se-enriched Flammulina Velutipes.