Structure analysis of polysaccharides purified from Cyclocarya paliurus with DEAE-Cellulose and its antioxidant activity in RAW264.7 cells

CPP was isolated from Cyclocarya paliurus (C. paliurus) and CPP-D was purified from CPP with a further step by DEAE-Cellulose. In this study, the structure and antioxidant activities of these two polysaccharides were investigated. The molecular weight of CPP was determined as 1.15 × 105 Da and the monosaccharides of it were Rha, Ara, Xyl, Man, Glc, Gal in a molar ratio of 0.021:0.237:0.020:0.036:0.454:0.231, while the molecular weight of CPP-D was 9.1 × 103 Da and the monosaccharides of it were Man, Glc, Gal in a molar ratio of 0.235:0.677:0.088. CPP-D consisted of three structural residues →4)-β-D-Glc-(1→, →2,6)-β-D-Man-(1→ and →4)-β-D-Gal. These structures were characterized by SEM, FT-IR, GC–MS, HPGPC, and NMR. The antioxidant assay in RAW264.7 cell showed that both CPP and CPP-D promoted cell viability and antioxidant activity, which decreased the content of MDA and increased the activity of SOD, T-AOC, CAT (P < .05). As a result, CPP-D isolated by DEAE-Cellulose didn't reduce the antioxidant activity of C. paliurus polysaccharide and could enhance the cell viability.