Study On The Preparation Of Novel Modified Polysaccharide Derivatives And Their Applications

Polysaccharide such as chitosan and cellulose is attractive in the fields of environment,energy,textile and biological medicine because of its natural and extensive source and renewability.The molecular structure of chitosan and cellulose contains a lot of functional groups,for instance,amide and/or hydroxyl,which can be used to synthetize various derivatives materials with novel structure and enhanced functionality.Quaternization is one of the most important derivative reactions of polysaccharide,and the modified products are applied in many areas due to the improved water-solubility and high isoelectric point.In this dissertation we prepared several novel qaternary ammonium modified chitosan or cellulose derivatives as static coating in capillary electrophoresis,or as solid phase for the enrichment of phosphopeptides.The main work is summarized as follows:1.Quaternized P-cyclodextrin grafted with chitosan(QCS-g-CD)was prepared by reacting chitosan with O-p-toluenesulfonyl-?-cyclodextrin(Ts-CD)under mild acidic condition.The reaction was performed by using chitosan and cyclodextrin as raw materials,p-toluenesulfonyl as leaving group and glycidyl trimethyl ammonium chloride as etherifying agent.FT-IR and XPS were used to characterize the properties of QCS-g-CD.When QCS-g-CD was used as the static coating in capillary inner surface,a relatively stable cathodic electroosmotic flow(EOF)in a broad range of pH 3.0?pH 12.0 was achieved-This coating could be used in capillary electrophoresis for the separation of analytes which possessed different molecular weight or state of charge.For examples,the baseline separation of nucleic acid bases,nucleosides and amino acids in a short time,the detection of polypeptides and the seperation of five of RNase B isomers.2.A novel polymer microsphere,derivative of chitosan and cellulose,was successfully prepared by reverse phase suspension polymerization and applied as the stationary phase during the dispersive extraction for the effective enrichment of phosphopeptides.This approach exhibited exceptionally high selectivity for phosphopeptides from ?-casein,a-casein and non-fat milk.The sensibility and anti-interference of this method were explored.Three phosphopeptides from P-casein at the 10 finol level could be captured and analyzed by MALDI-TOF-MS.3.The cationic quaternized luffa sponge was prepared by using luffa sponge as raw material and 3-chloro-2-hydroxypropyltrimethylammonium chloride as etherifying agent.It was used as the stationary phase during the solid phase extraction for the effective enrichment of phosphopeptides.The selectivity,sensibility and anti-interference of this method were explored.The experimental results indicated that the approach exhibited good performance not only for phosphopeptide enrichment from the model protein ?-casein and ?-casein but also the real sample non-fat milk.