Structural characterization and antioxidant activity evaluation of a polysaccharide from pink Auricularia cornea.

An acidic polysaccharose (YL-D2N2) was isolated from crude polysaccharides of pink Auricularia cornea and characterized for its structural and antioxidant properties. YL-D2N2 consists of fucose, galactose, glucose, xylose, mannose and glucuronic acid in a molar ratio of 0.85: 1.50: 4.44: 27.52: 46.56: 19.13. It has a number-average molecular weight of about 52.811 kDa and a weight-average molecular weight of about 135.457 kDa. Structural characterization showed that YL-D2N2 consists of nine residues (Xylp-(1→, GlcpA-(1→, →2)-Xylp-(1→, →3)-Galp-(1→, →3)-Manp-(1→, →4)-GlcpA-(1→, →2,3)-Manp-(1→, →3,4)-Glcp-(1→, →3,6)-Manp-(1→), with a backbone of →3)-β-D-Manp-(1→, →2,3)-α-D-Manp-(1→, →3,6)-α-D-Manp-(1 → and side chains containing β-D-Xylp-(1 → and α-D-GlcpA-(1→. Notably, YL-D2N2 exhibits significant radical scavenging activity for superoxide anions, reaching 50.82 ± 0.64 % at a concentration of 3.2 mg/mL. Overall, YL-D2N2 exhibits a unique chemical structure and specialized applications for targeting superoxide anion radicals, providing valuable insights for further exploration of its structure-activity relationship.