Structure of epiglucan, a highly side-chain/branched (1 -> 3;1 -> 6)-beta-glucan from the micro fungus Epicoccum nigrum Ehrenb. ex Schlecht

The extracellular fungal polysaccharide, epiglucan, synthesised by Epicoccu m nigrum is a side-chain/branched (1-->3:1 --> 6)-D-beta -glucan. Methylati on analysis, C-13 DEFT NMR and specific enzymic digestion data show slight variation in branching frequency among the epiglucans from the three strain s examined. The (1-->3)-beta -linked backbone has (1 --> 6)-beta -linked br anches at frequencies greater than the homologous glucans, scleroglucan and schizophyllan, from Sclerotium spp. and Schizophyllum commune, respectivel y. The structural analyses do not allow a distinction to be made between st ructures I and II. [GRAPHICS] Epiglucan displays non-Newtonian shear thinning rheological properties, typ ical of these glucans. (C) 2001 Elsevier Science Ltd. All rights reserved.