Glucomannan and branched (1→3)(1→6) β-glucan from the aposymbiotically grown Physcia kalbii mycobiont

Phytochemistry. 2012 Dec:84:88-93. doi: 10.1016/j.phytochem.2012.08.010. Epub 2012 Sep 13.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Lichens / chemistry*
  • Lichens / growth & development
  • Mannans / chemistry*
  • Mannans / isolation & purification
  • Nuclear Magnetic Resonance, Biomolecular
  • beta-Glucans / chemistry*
  • beta-Glucans / isolation & purification

Substances

  • Mannans
  • beta-Glucans
  • (1-6)-alpha-glucomannan