Extraction, Isolation, Characterization And Chemical Modification Of Chaenomeles Speciosa Polysaccharides

In this thesis, water-soluble polysaccharides from Chaenomeles Speciosa were extracted,isolated and characterized. The refined polysaccharides was chemically modified to sulfatedpolysaccharides. The antioxidant activities of the obtained polysaccharides were also tested.The crude polysaccharide was extracted by the method of hot water lixiviation followedby ethanol precipitation. The optimum extraction condition was established through one-wayexperiments and orthogonal experiment, in which is the extraction temperature is96℃, theextraction time is3h, the water/liquid ratio is1:40, the ethanol/liquid ratio is3:1, Under theoptimum extraction condition, the extraction rate of crude polysacchride reaches5.0%, andthe contents of polysacchride are63.29%.The refined polysacchride can be obtained by Sevag method, dialysis and SephadexG-100gel column chromatography, the contents of which are96.29％. The molecularweight is Mw=27622and Mn=13950, determined by HPGPC method.The monosaccharidecomposition of polysaccharides from chaenomeles speciosa obtained by the GC method. Theexperimental results indicated that polysaccharide consists of glucose. IR and1HNMRsuggest that the polysaccharide was a type of pyrane polysaccharide of α-glucosidal bond.Sulfated polysaccharides from chaenomeles speciosa were synthesized by the method ofchlorosulfonic acid. The optimum condition was determinded, in which chlorosulfonic acid／material is30／1.the reaction temperature is30℃and the reaction time is2h. Replacedegree of sulfur is2.41. IR showed the absorption of S=O in-OSO3at1246cm-1and C-O-Sat810cm-1.The antioxidant activities of polysaccharides to·OH-and·O₂-were tested. The resultsindicate that all the two polysaccharides have obvious antioxidant properties.