Structural characterisation of novel lichen heteroglycans by NMR spectroscopy and methylation analysis

Sesseja Omarsdottir, Bent O. Petersen, Berit Smestad Paulsen, Adiaratou Togola, Jens Øllgaard Duus, Elin S. Olafsdottir

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

Two galactofuranomannans, Ths-4 and Ths-5, were isolated from the lichen, Thamnolia vermicularis var. subuliformis, using ethanol fractionation and anion-exchange and size-exclusion chromatography. The average molecular weights of Ths-4 and Ths-5 were estimated to be 19 and 200 kDa, respectively. Structural characterisation of Ths-4, Ths-5 and their partially hydrolysed derivatives was performed by methanolysis and methylation analysis. The intact and partially hydrolysed Ths-4 was further analysed using NMR spectroscopy (1D, COSY, NOESY, TOCSY, HSQC and HMBC). According to the data obtained, the heteroglycans Ths-4 and Ths-5 have similar structures, but have large differences in molecular weight. The structure is composed of 3-O-linked and 5-O-linked galactofuranosyl chains linked to a mannan core. The mannan core consists of a main chain of alpha-(1 -> 6)-linked mannopyranosyl residues, substituted at O-2 with either a single alpha-mannopyranosyl unit or an alpha-Manp-(1 -> 2)-alpha-Manp-(1 -> 2)-alpha-Manp group in the ratio of approximately 1:3, respectively. The polysaccharides have idealised repeating blocks as is shown. (c) 2006 Elsevier Ltd. All rights reserved.
Original languageEnglish
JournalCARBOHYDRATE RESEARCH
Volume341
Issue number14
Pages (from-to)2449-2455
Number of pages7
ISSN0008-6215
DOIs
Publication statusPublished - 2006

Keywords

  • Chromatography, Ion Exchange
  • Glucans
  • Lichens
  • Magnetic Resonance Spectroscopy
  • Methylation
  • Plant Preparations
  • Polysaccharides
  • Ethanol
  • Fractionation
  • Ion exchange
  • Molecular weight
  • Nuclear magnetic resonance spectroscopy
  • Size exclusion chromatography
  • alcohol
  • glycan derivative
  • anion exchange
  • article
  • chemical reaction
  • chemical structure
  • gel permeation chromatography
  • high performance liquid chromatography
  • hydrolysis
  • methanolysis
  • methylation
  • molecular weight
  • nuclear magnetic resonance spectroscopy
  • nuclear Overhauser effect
  • phase separation
  • plant
  • priority journal
  • reaction analysis
  • structure analysis
  • substitution reaction
  • thamnolia vermicularis
  • Thamnolia
  • Thamnolia vermicularis
  • Galactofuranomannan
  • Methylation analysis
  • NMR spectroscopy
  • X
  • BIOCHEMISTRY
  • CHEMISTRY,
  • NUCLEAR MAGNETIC-RESONANCE
  • CELL-WALL POLYSACCHARIDES
  • SUBULIFORMIS
  • SEPARATION
  • lichens
  • galactofuranomannan
  • methylation analysis
  • Plantae (Nonvascular Plants, Plants) - Lichenes [19000] Thamnolia vermicularis var. subuliformis variety
  • alpha(-1-6)-linked mannopyranosyl residue
  • galactofuranosyl chain
  • lichen heteroglycan
  • Ths-4
  • Ths-5
  • 10060, Biochemistry studies - General
  • 10062, Biochemistry studies - Nucleic acids, purines and pyrimidines
  • 51522, Plant physiology - Chemical constituents
  • anion-exchange chromatography laboratory techniques, chromatographic techniques
  • ethanol fractionation laboratory techniques
  • methylation analysis laboratory techniques, genetic techniques
  • NMR laboratory techniques, spectrum analysis techniques
  • NMR spectroscopy laboratory techniques, spectrum analysis techniques
  • size-exclusion chromatography laboratory techniques, chromatographic techniques
  • Biochemistry and Molecular Biophysics
  • Methods and Techniques

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