低相对分子质量硫酸软骨素的制备及其性质

Preparation and Properties of Low Molecular Weight Chondroitin Sulfate

以过氧化氢+铜离子(Ⅱ)体系自由基法降解制备了低相对分子质量(简称分子量,下同)硫酸软骨素,并采用元素分析、红外光谱、原子力显微镜进行了结构表征和物化性质分析。结果表明,铜离子催化氧化降解后硫酸软骨素重均分子量从56 596降到6 906,己糖醛酸、氨基己糖及硫酸根等主要成分变化不大,差异不显著,降解前后热分解特性一致。原子力显微镜分析发现,降解前后硫酸软骨素在水中均以多股螺旋棒状形式存在,降解过程中,螺旋链部分断裂。结合红外光谱图,可以推测自由基引起的降解主要是造成硫酸软骨素二糖间β-1,4糖苷键断裂,而对β-1,3糖苷键无影响。

Low molecular weight chondroitin sulfate was first prepared by free radical polymerization with hydrogen peroxide in the presence of copper （ Ⅱ ） iron. Its characterization and physieochemical properties were investigated by physicochemical methods including chemical composition, elementary analysis, IR and AFM. The results show that the molecular weight of chondroitin sulfate decreased from 56 596 to 6 906 after copper catalytic oxidation. The major ingredients, such as hexuronic acid, hexosamine and sulfate radical, didn＇t exhibit significant change after degradation. The TG-DSC analysis shows that the mechanism of thermal decomposition is similar. The AFM analysis indicates that this sample existed in aqueous solution in the form of stranded spiral. Part of the spiral ruptured during degradation. IR analysis shows that the degradation process might cause β-1,4 glycosidic bond to fracture,but it had no effect on β-1,3 glycosidic bond.