Three aldoses, six alditols, eight oligosaccharides, three polysaccharides and a glycopeptide were found in a Sticta sp. The most interesting of these were gentiobiose, -triose and -tetraose, O-α-D-Galp-(1→6)-O-β-D-Galp-(1→1)-D-glyceritol released on alkaline treatment, and a polysaccharide with predominant (1→4)-linked β-D-Xylp units. Present were a galactoglucomannan, a polysaccharide, possibly a mixture, containing β-D-Galf, and α-L-Araf units and a glycopeptide with α- and β-D-Galf, Galp, Glcp and Manp units, having a core with successive (1→2)-linked α-D-Manp residues substituted at O-3 with those of α-D-Galf. After four years storage of the lichen, the contents of the principal polyols, ribitol (0.86%), arabinitol (0.99%) and mannitol (2.50%) fell to practically zero, with the appearance of threitol (0.03%), xylitol (0.01%) and myo-inositol (0.03%). Also, the protein content fell from 34 to 18%. The most abundant amino acids were valine (10.5% of total) in fresh lichen and threonine (14.6%) in stored lichen.
carbohydrates, protein, glycopeptide, Sticta sp., Stictacea, compositional variation on storage
NCBI PubMed ID: 7763796Publication DOI: 10.1016/0031-9422(93)85446-XJournal NLM ID: 0151434Publisher: Elsevier
Institutions: Departamento de Bioquimica, Universidade Federal do Parani, Curitiba, Brazil, Departamento de Ciências Biológicas, Pontificia Universidade Católica, Curitiba, Brazil
Methods: 13C NMR, 1H NMR, GC-MS, paper chromatography, ion-exchange chromatography, extraction, acetylation, CC, alkaline extraction
Found