Abstract: Polysaccharides of Lycium barbarum were separated followed by their structure characterization and in vitro gut metabolism analysis,which gave clues for their future utilities and standard quality evaluations in this study.Total polysaccharide of Lycium barbarum(LBP) were extracted at first,followed by DEAE-650M and Sephadex G25 column purifications using medium pressure liquor chromatography (MPLC) instrument.As results,four major fractions (LBP-1-4) were separated from LPS with success.They showed similar relative molecular weight to be 65.58,63.83,62.67 and 65.58 kD respectively as measured by HPSEC.They were all composed of 6 monosaccharides (Fuc,Ara,Rha,Man,Gal and Glc),of which arabinose and galactose were relative abundant as measured by HPEAC-PAD method.UV-Vib methods were used to measure the total amount of their sugar,glucuronic acid and protein contents,and the results of which indicated to be 64.08%-73.05%,8.5%-18.0% and 7.27%-18.67% respectively.LBP was stable in artificial gastric juice,while unstable in artificial intestinal juice or rat intestinal flora solution.These results could be beneficial for preparation and quality control of LBP as well as its potential utilizations.

Key words: Lycium barbarum, polysaccharide, separation, structure analysis, gut metabolism