The polysaccharides were acquired from the seeds of T. sinensis by hot water extraction, ethanol precipitation, decoloration with macroporous 900 resin, and deproteinization with sevag reagent, which possessed significantly immunomodulatory activity on the levels of IgA, IgG, and IgM, the relative indices of thymus and spleen, and the phagocytosis index of mice in vivo. T. sinensis seeds polysaccharides (TSP) were separated and purified using DEAE-52 cellulose and Sephacryl S-300 column chromatography to obtain TSP-3a characterized of molecular weight, monosaccharides composition, and other preliminary structural features. TSP-3a (758.6 kDa) mainly contained Man, GalN, GlcA, Rha, Glc, Gal, Ara, and Fuc in a molar ratio of 0.26:0.24:0.19:1.80:0.45:12.56:1.09:0.21. FT-IR analysis suggested TSP-3a was an acid polysaccharide and the presence of β configuration within the TSP-3a was discovered. Combining 1H NMR, 13C NMR, and comparison with those reported in the literature, the backbone of TSP-3a might contain →6)-α-D-Glc-(1→, →3)-β-D-GlcA-(1→, →6)-α-D-Gal-(1→, α-D-Glc-(1→, and →6)-β-D-Gal-(1→.[Figure: see text].
Keywords: Meliaceae; Toona sinensis (A. Juss.) Roem; characterization; immunomodulatory activity; polysaccharide.