Chemotyping glucans from lichens of the genus Cladonia

alpha-D-Glucans were isolated from the Cladonia spp., C. clathrata, C. conn exa, C. crispatzlla, C. furcata, C. ibitipocae, C. imperialis, C. penicilla ta, and C. signata, to evaluate their possible significance in chemotyping. Each was isolated in water-insoluble form via successive alkaline extracti on and freeze-thawing. They were then individually investigated using C-13 and H-1-NMR spectroscopy (including COSY, TOCSY and HMQC techniques), methy lation analysis, and Smith degradation, and their specific rotations and mo nosaccharide compositions determined. Each alpha-D-glucan contained alterna ting (1 --> 3) and (1 --> 4)-linkages (1:1 ratio), as determined by the rel ative areas of their respective H-1 signals at delta 5.14 and 5.23. Also, t he respective relative areas of C-1 signals at delta 99.2 and 100.1, and th ose of C-3 of 3-O-(delta 82.6) and C-4 of 4-O-substituted (delta 78.9) unit s, were similar for each glucan. The presence of alpha-D-glucans of the nig eran type appears to be typical of Cladonia spp. (C) 1999 Elsevier Science Ltd. All rights reserved.