Preparation, structural analysis and antioxidant activities of phosphorylated (1 → 3)-β-D-glucan

The aim of this study was to investigate the effect of phosphorylation on the antioxidant activity of (1 -> 3)-beta-D-glucan from yeast cell wall. Alkali-insoluble (1 -> 3)-beta-D-glucan was extracted from yeast cell wall by an acidbase method. It was found that the purity of the sample was greatly improved after the precipitation was treated with alkali at 90. and then by acetic acid, which was about 96.5%. Phosphorylated (1 -> 3)-beta-D-glucan was prepared. Infrared (IR) spectra and nuclear magnetic resonance spectra (NMR) confirmed the successful introduction of phosphate into glucan. The substitution degree of phosphate was 0.18. The phosphorylated (1 -> 3)-beta-D-glucan could significantly increase SOD and CAT contents in serum, liver and brain of mice, and reduce MDA level in serum, liver and brain to a certain extent in vivo. This lays a solid foundation for the research and development of phosphorylated (1 -> 3)-beta-D-glucan antioxidant.