title: Glucomannan and branched (1→3)(1→6) β-glucan from the aposymbiotically grown Physcia kalbii mycobiont.
abstract: Cultures of the mycobiont Physcia kalbii were obtained from germinated ascospores and cultivated on Sabouraud-Sucrose-agar medium. Alkaline extraction of freeze-dried mycelia provided a branched (1→3),(1→6)-β-glucan and a glucomannan, whose chemical structure was determined by monosaccharide composition, methylation, controlled Smith degradation and NMR spectroscopic analysis. The β-glucan had a (1→3)-linked β-glucopyranosyl backbone, partially substituted (approx. 50% of the units) at O-6. The side chains were formed by 6-O- (∼82%) and 2,6-O-linked-β-Glcp units, while the non-reducing ends were formed by β-glucopyranosyl residues. The glucomannan had (1→6)-linked α-Manp units in the main chain, almost all being substituted at O-2 by α-Manp and α-Glcp units. This glucomannan could be a typical polysaccharide of lichens from the family Physciaceae.
authors.affiliation: Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Paraná, CP 19.046, CEP 81.531-980, Curitiba, PR, Brazil. lucimaramcc@ufpr.br
authors.forename: Lucimara M C
authors.initials: LM
authors.lastname: Cordeiro
authors.forename: Vanessa de Fátima
authors.initials: Vde F
authors.lastname: Reinhardt
authors.forename: Marcello
authors.initials: M
authors.lastname: Iacomini
mesh_terms: D008011:Lichens / Q000737:chemistry* / Q000254:growth & development; D008351:Mannans / Q000737:chemistry* / Q000302:isolation & purification; D019906:Nuclear Magnetic Resonance, Biomolecular; D047071:beta-Glucans / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D008351:Mannans; D047071:beta-Glucans; C022901:(1-6)-alpha-glucomannan