Abstract: The structural features of polysaccharide ASP3 were studied by partial acid hydrolysis and methylation methods, combined with GC-MS instrument. ASP3 was hydrolyzed with 0.2 mol/L trifluoroacetic acid and methylation analysis method were conducted on the samples. The results indicate that the residues of sugar constituents were mainly D-GalpA, D-Galp, L-Araf and L-Rhap. ASP3 contained the main part of homogalacturonan fragments as “smooth regions” with 1,4-D-GalpA and rhamnogalacturonan segments as “hairy regions”. A total of 58.8% Rhap residues in the backbone were substituted at O-4 position by side chains. T-, 1,5-, 1,3,5-Araf and T-, 1,6-, 1,3,6-, 1,4-, 1,4,6-D-Galp were linked as arabinogalactan, galactan and arabinan, which were the mainly constitution of the branch.

Key words: Angelica sinensis, Polysaccharides, Methylation analysis, Partial acid hydrolysis