Synthesis, Characterization And Biological Activities Of New Kinds Of Schiff Bases Derivatives Of Chitosan

A series of Chitosan Schiff bases derivatives in the C₆-position or C₂-position and C₆-position of Chitosan were synthesized in this thesis.The aim of this study was to improve the antibacterial activity of Chitosan,to improve the solubility of Chitosan,and to further clarify the relationship between Chitosan molecular structure and antibacterial effect.Three different C₆-aniline Schiff bases derivatives of Chitosan and three different C₂-benzaldehyde-C₆-aniline double Chitosan Schiff bases derivatives were synthesized.The structure and properties of the newly synthesized products were characterized by Fourier transform infrared spectroscopy,13C NMR,SEM images and elemental analysis.The results of elemental analysis showed that the degree of substitution?DS?was 37.6%?48.2%.The synthetic compound exhibits excellent solubility in an organic solvent.In this thesis,six kinds of Chitosan Schiff bases derivatives were tested by Staphylococcus aureus?S.aureus?and Escherichia coli?E.coli?,and the results showed that the prepared Chitosan derivatives had significantly improved antibacterial activity toward S.aureus and E.coli.The C₆-p-Toluidine Schiff bases derivative of Chitosan?6-p-TSCS?had the best antibacterial activity against S.aureus,while the C₂-benzaldehyde-C₆-o-Toluidine double Schiff bases derivative?2-B-6-o-TDSCS?has the best antibacterial activity against E.coli.At the same time,six kinds of synthetic Chitosan Schiff bases derivatives were tested for antioxidant test,including the determination of hydroxyl radical,superoxide anion,DPPH radical and reducing ability.The experimental results show that 6-ASCS had stronger antioxidant activity than Chitosan against hydroxyl radical,superoxide anion and DPPH radical.However,the 6-p-TSCS had great reducing ability.Furthermore,six kinds of Chitosan Schiff bases derivatives were tested by the cell of SCG-7901,and the results showed that the prepared Chitosan derivatives have low toxicity,much lower than that of Chitosan and C₂-benzaldehyde Schiff bases of Chitosan.This study provides experimental basis and research ideas for the research and development of chitosan derivatives.