Structural characterization of a branched (1→6)-α-mannan and β-glucans isolated from the fruiting bodies of Cantharellus cibarius

• Published in: Carbohydrate polymers 2016-08, Vol.146, p.197-207
• Main Authors: Nyman, Anna Armika T., Aachmann, Finn L., Rise, Frode, Ballance, Simon, Samuelsen, Anne Berit C.
• Format: Article
• Language: English
• Subjects: Agaricales - chemistry; Basidiomycota; beta-Glucans - chemistry; Chanterelle; Fruiting Bodies, Fungal - chemistry; Glucan; Magnetic Resonance Spectroscopy; Mannan; Mannans - chemistry; Molecular Structure; NMR; Saccharomyces cerevisiae
• ISSN: 0144-8617; 1879-1344
• DOI: 10.1016/j.carbpol.2016.03.052

•The chanterelle cell wall contains an (1→6)-α-mannan, (1→6)- and (1→3)-β-glucans.•The α-mannan is a water soluble polysaccharide extracted in boiling water.•The release of β-glucans requires treatment with hot alkali solution. A comprehensive characterization of polysaccharides from the chanterelle was performed. Experiments included both linkage analysis by methylation and GC–MS, monosaccharide composition analysis by methanolysis, SEC-MALLS and several NMR experiments including COSY, HSQC, TOCSY, HSQC-TOCSY, NOESY, and HMBC. A 671kDa (1→6)-linked α-d-mannan with single and short (1→2)-linked side chains (WCcF1b) was isolated from the hot water extract, after protease treatment and fractionation by size exclusion chromatography. The hot 1M NaOH extract contained two types of β-glucan; a water soluble (1→6)-linked β-d-glucan with single and short (1→3)-linked β-glucan side chains (ACcSw) and a less branched (1→3)-linked β-d-glucan (ACcIw/ACcId), proposed to contain short side chains in O-4. Chemical shifts assignments of the α-mannan and β-glucan are presented as well as chemical shift values obtained from a (1→6)/(1→3)-β-d-glucan derived from Saccharomyces cerevisiae which was used as reference.