壳寡糖前驱体的制备与表征

研究了一种简单的用化学选择性来保护壳寡糖氨基的方法,用于制备N-邻苯二甲酰化壳寡糖,这种可溶性N-保护壳寡糖前驱体对壳寡糖进一步进行可控化学修饰非常重要.通过控制邻苯二甲酸酐与壳寡糖的摩尔比、反应时间及反应温度制备了取代度不同、产物组成均一的环状酰亚胺型邻苯二甲酰化壳寡糖前驱体,并用红外光谱法、X射线衍射对N-邻苯二甲酰化壳寡糖的取代度、分子结构等进行了表征.结果表明:随着邻苯二甲酸酐与壳寡糖氨基摩尔比的增加,产物的取代度增大,与有机溶剂的亲和性增加.XRD也表明,尽管壳寡糖链上悬挂很大的取代基,但N-邻苯二甲酰化壳寡糖却具有结晶性.

Preparation and Characterization of Chitosan Oligosaccharide Precursor

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.