Galactomannoglucans of lichenized fungi of Cladonia spp.: significance as chemotypes

The chemical structures of the glucans, galactoglucomannans and galactomann oglucans of two species of the Cladonia, section Cocciferae, Cladonia minia ta and Cladonia salmonea, were determined and compared. alpha-D-Glucans of the nigeran type were isolated from both species, in common with all Cladon ia spp., along with galactoglucomannans containing (1 --> 6)-linked main-ch ains of alpha-D-Manp units substituted by structurally different and typica l side-chains. Isolated were previously unreported galactomannoglucans, wit h (1 --> 3)-linked main-chains of beta-D-Glcp units; substituted at O-2,6 b y side-chains. These consisted of beta-D-Galf, 6-O-substituted beta-D-Galf and 2-O-, 4-O-, 6-O- and 2,3-di-O-substituted alpha-D-Manp units. According to C-13 NMR spectroscopy, a similar galactomannoglucan was isolated from t he Cladonia spp. Cladonia signata, Cladonia crispatula, Cladonia penicillat a, Cladonia imperialis, Cladonia clathrata, Cladonia connexa, Cladonia subs tellata and Cladonia ibitipocae. Its presence could also contribute to the classic taxonomy of lichenized fungi, (C) 1999 Federation of European Micro biological Societies. Published by Elsevier Science B.V. All rights reserve d.