Structural characterization, and in vitro hypoglycemic activity of a polysaccharide from the mushroom Cantharellus yunnanensis

A polysaccharide CY-2 from C. yunnanensis was obtained through a process of consecutive water extraction, alcohol precipitation, and DEAE-52 fast-flow chromatography. CY-2, with an average molecular weight of 2.69 × 104 Da mainly consisted of glucose and mannose with a molar ratio of 33.5: 56.9. Infrared spectrum (IR), methylation analysis, and nuclear magnetic resonance (NMR) results revealed that CY-2 may have a backbone consisting of →6)-α-D-Manp-(1 → 3)-β-D-Glcp-(1→, and branch chain β-D-Glcp-(1→. Meanwhile, CY-2 had a higher inhibition rate on α-glucosidase activity compared with other fractions (CY-0, CY-1, and CY-4) and was a mixed competitive inhibitor. In addition, CY-2 at the concentration of 10 μg/mL presented a superior power to improve glucose consumption and metabolism in HepG2 cells compared with metformin. Overall, these findings highlight the potential value of CY-2 as a hypoglycemic agent.