Three different glucans (PS-I, PS-II, and PS-III) were isolated from the alkaline extract of the fruiting bodies of an edible mushroom Pleurotus florida, cultivar Assam Florida. On the basis of total acid hydrolysis, methylation analysis, periodate oxidation, Smith degradation, and NMR experiments (H-1, C-13, DEPT-135, DQF-COSY, TOCSY, NOESY, ROESY, HMQC, and HMBC), the structure of the repeating unit of these polysaccharides was established as follows: PS-I: -> 3)-alpha-D-Glcp-(1 -> 3)-beta-D-Glcp-(1 -> 6)-beta-D-Glcp-(1 -> 6 up arrow 1 alpha-D-Glcp PS-II: -> 3)-alpha-D-Glcp-(1 -> PSIII: -> 3)-beta-D-Glcp-(1 -> (C) 2010 Elsevier Ltd. All rights reserved.