防风均一多糖SP800301的化学结构研究

Chemical structure of a polysaccharide SP800301 from Saposhnikoviae Radix

目的对从防风中分离得到的均一多糖SP800301进行结构解析,确定化学结构。方法采用二乙氨基乙基(DEAE)-纤维素、葡聚糖凝胶G-75等柱色谱法,分离纯化防风多糖;采用电喷雾串联质谱、气相色谱质谱联用、核磁共振等技术,对分离得到的防风均一多糖SP800301的分子量分布、单糖组成、寡糖片段、糖残基类型和糖苷键连接方式等进行分析,确定结构;采用电子显微镜和原子力显微镜扫描法表征防风均一多糖SP800301的外貌特点。结果防风多糖SP800301均一性良好,分子量为9.1×10~4g/mol,糖醛酸含量52.72%,由鼠李糖、半乳糖醛酸、葡萄糖、半乳糖和阿拉伯糖组成,摩尔比为4.3∶58.1∶25.4∶5.0∶7.3。主要以聚半乳糖醛酸为主链,支链由鼠李糖、半乳糖醛酸、半乳糖、葡萄糖和阿拉伯糖组成,其中,阿拉伯糖在支链末端,糖链中部分半乳糖醛酸形成了甲酯。结论明确了防风中均一多糖SP800301的化学结构,丰富了防风中多糖的化学成分内涵,为进一步研究防风多糖的免疫调节作用机制奠定基础,为防风在临床的应用提供科学依据。

Objective To perform structural analysis on the homogeneous polysaccharide SP800301 isolated from Saposhnikoviae Radix to determine its chemical structure.Methods Polysaccharides were separated and purified from Saposhnikoviae Radix using column chromatography,such as DEAE-cellulose and Sephadex G-75.The molecular weight distribution,monosaccharide composition,oligosaccharide fragments,sugar residue types,and glycosidic bond connection of the isolated homogeneous polysaccharide SP800301 from Saposhnikoviae Radix were analyzed using electrospray ionization multistage mass spectrometry,gas chromatography-mass spectrometry,and nuclear magnetic resonance to determine its structure.The appearance characteristics of the Saposhnikoviae Radix polysaccharide were characterized using electron and atomic force microscopy.Results Polysaccharide SP800301 extracted from Saposhnikoviae Radix had good homogeneity with a molecular weight of 9.1×104 g/mol.The uronic acid content was 52.72%.The monosaccharide group comprised rhamnose,galacturonic acid,glucose,galactose,and arabinose,with a molar ratio of 4.3:58.1:25.4:5.0:7.3.The polysaccharide was mainly composed of polygalacturonic acid as the primary chain.The branched chain was comprised of rhamnose,galacturonic acid,galactose,glucose,and arabinose,with arabinose at the end of the branched chain and part of the galacturonic acid in the sugar chain forming a methyl ester.Conclusion This study clarified the chemical structure of the homogeneous polysaccharide SP800301 from Saposhnikoviae Radix,enriched the chemical composition of Saposhnikoviae Radix polysaccharides,laid the foundation for further research on the immune regulatory mechanism of Saposhnikoviae Radix polysaccharides,and provided a scientific basis for clinically using Saposhnikoviae Radix.