Purification And Composition Analysis Of Se-Enriched Sweet Potato Neutral Selenium Polysaccharide

The separation and purification method and composition structure of sweet potato selenium polysaccharides were explored,and the connection mode between selenium and monosaccharides in the polysaccharides was speculated based on the analysis of the composition structure of selenium polysaccharides,which enriched the research content of the separation and purification and structure composition of selenium polysaccharides in sweet potato at home and abroad,and had practical significance for the research in the field of enriching selenium polysaccharides.In this paper,the polysaccharides in sweet potato were transformed into selenium polysaccharides by artificial biological selenium enrichment method,and the separation,purification and composition of selenium polysaccharides were studied.The crude selenium polysaccharide of sweet potato was extracted by water extraction and alcohol precipitation,and the yield was 1.98%.The technological conditions of polyamide column chromatography to take off the protein were determined as follows:sample loading 600 mg,sample volume 2/5 times column volume,adsorption time 20 min,elution rate 4.5 ml·min^-1.The total sugar content and protein content of Se-polysaccharide were 98.33%and 9.6%,respectively.The Se-polysaccharides were composed of mannose,ribose,rhamnose,glucose,galactose,xylose,arabinose and fucose.No nucleic acid and free protein were detected by UV spectra.IR spectrum showed that it was pyran selenium polysaccharide and the existence of-C-O-Se-bond is also confirmed.The results of monosaccharide composition and infrared spectrum analysis were confirmed by NMR hydrogen spectrum and carbon spectrum respectively.The total selenium content in sweet potato was 0.71 mg·kg^-1,and the selenium content in SPSP1 was0.027 mg·kg^-1.Molecular weight of selenium polysaccharide Mn=2.386×10⁴.