Chemical structure and inhibition on α-glucosidase of a novel polysaccharide from Hypsizygus marmoreus

In this study, the crude polysaccharide (HMP) was extracted from Hypsizygus marmoreus using water-extraction and alcohol-precipitation methods. The separation and purification were performed followed by the preparation of the homogeneous polysaccharide termed as HMP-1. The structural feature of HMP-1 was investigated by a combination of chemical and instrumental analyses. The results showed that the average molecular weight of HMP-1 was 1.92 x 10(3) kDa. Besides, monosaccharide composition analysis showed that the HMP-1 mainly consist of o-mannose, D-glucose and D-galactose in the molar ratio of 1.145:5.282:1.157. The periodate oxidation, smith degradation and methylation results revealed that the main chain of HMP-1 was composed by -> 4)-D-Glcp-(1 ->, -> 6)-D-Galp-(1 ->, -> 4,6)-D-Glcp-(1 -> and D-Glcp-(1 ->, while the side chain was -> 3)-D-Manp-(1 ->, D-Manp-(1 -> and D-Glcp-(1 -> . alpha-Glucosidase inhibitory activity experiment result showed that HMP-1 was able to inhibit the activity of alpha-glucosidase. Therefore, as the chemical structure and biological activity of HMP-1 were clearly characterized, Hypsizygus marmoreus can be used as a reference source for drug preparations. (C) 2020 Elsevier B.V. All rights reserved.