关键词: 壳寡糖, 前驱体, 氨基, 化学选择性保护, 结晶性

Abstract: A simple and convenient procedure for chemoselective protection of the amino groups of chitosan oligosaccharide was developed to prepare N-phthaloyl-chitosan oligosaccharide. It is indispensable to the soluble N-protected precursor to modify chemoselectively the reactions of chitosan oligosaccharide. A series of N-phthaloyl-chitosan oligosaccharide precursors were prepared at different levels of substitution with the same homogeneity of constituents by way of controlling the mole ratio of phthalic anhydride to chitosan oligosaccharide and reaction time/temperature. The level of substitution and molecular structure of the precursors prepared were characterized with FTIR and XRD. The results showed that the level of substitution and affinity of organic solvents both increase with the increasing mole ratio as above. XRD patterns showed that the N-phthaloyl-chitosan oligosaccharide can crystallize though there is a bulky substituent group hung from it.