Glucans of lichenized fungi:: significance for taxonomy of the genera Parmotrema and Rimelia

The glucans of lichenized fungi are an important class of polysaccharides with structural and chemotaxonomic roles. The water-insoluble glucans of the genus Parmotrema (P. austrosinense, P. delicatulum, P. mantiqueirense, P. schindleri, and P. tinctorum) and those of Rimelia (R. cetrata and R. reticulata), were investigated in order to evaluate the significance in chemotyping, with nigeran [(1 -> 3), (1 -> 4)-alpha-glucan] and lichenan [(1 -> 3),(1 -> 4)-beta-glucan] characterized using H-1 and C-13 NMR, methylation analysis, and controlled Smith degradations. Results from all species were similar, suggesting that glucan chemistry does not support separation of Rimelia from Parmotrema. (c) 2005 Elsevier Ltd. All rights reserved.