Structural and functional analyses of three purified polysaccharides isolated from Chinese Huaishan-yams

The extraction, purification and structural of Chinese Huaishan-yams polysaccharides and their function were investigated in this study. Three water-soluble polysaccharides, designated as CYZ, CYS-1, CYS-2, were purified and the molecular weight were found to be 22 KDa, 41 KDa and 23 KDa, respectively. The HPLC results showed that they were composed of different monosaccharides and the content of monosaccharides varied significantly. ¹H NMR and ¹³C NMR spectra showed that CYS-1 contained two α-type and four β-type glycosidic linkages and backbone of CYS-1 has two types of linkages, β-1 → 2 and β-1 → 4. CYS-2 contained two α type and three β-type glycosidic linkages, and the backbone has three types of linkages, β-1 → 2, β-1 → 4, and β-1 → 6. The antioxidant activities increased in the order of CYS-1 < CYZ < CYS-2 < crude polysaccharide. Further, crude polysaccharide CYS-1 (≥80 μg/mL) had a good ability of inhibiting α-glucosidase and significant inhibition on the relative proliferation rate of B16 murine melanoma cells middle dose (≥200 μg/mL).