A heteropolysaccharide from aqueous extract of an edible mushroom, Pleurotus ostreatus cultivar: structural and biological studies

A water soluble polysaccharide isolated from the hot aqueous extract of Pleurotus ostreatus cultivar was found to contain D-glucose and D-galactose in a molar ratio of nearly 7:1. Structural investigation was carried out using acid hydrolysis, methylation analysis, periodate oxidation. Smith degradation, and NMR studies (H-1, C-13, DEPT-135, TOCSY, DQF-COSY, NOESY, ROESY, HMQC, and HMBC). On the basis of the above mentioned experiments the structure of the repeating unit of the polysaccharide was established as: C E D C E D -> 3)-beta-D-Glcp-(1 -> 6)-beta-D-Glcp-(1 -> 6)-beta-D-Glcp-(1 -> 3)-beta-D-Glcp-(1 -> 6)-beta-D-Glcp-(1 -> 6)-beta-D-Glcp-(1 -> 3 3 up arrow up arrow 1 1 alpha-D-Galp alpha-D-Glcp A B This heteroglycan stimulates macrophages, splenocytes, and thymocytes. (C) 2010 Elsevier Ltd. All rights reserved.