Chemical structure of a polysaccharide SP800301 from Saposhnikoviae Radix
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.