Structural investigation of water-soluble polysaccharides extracted from the fruit bodies of Coprinus comatus

Water-soluble polysaccharide material, extracted from the stipes of the fruit bodies of Coprinus comatus by hot water, was fractionated by sequential weak anion-exchange and size-exclusion chromatography. The relevant fractions were subjected to structural analysis, including (d/l) monosaccharide/methylation analysis and 1D/2D NMR spectroscopy. Besides the disaccharide α,α-trehalose [α-d-Glcp-(1↔1)-α-d-Glcp], high-molecular-mass α-d-glucans (the most abundant component) consisting of [→4)-α-d-Glcp-(1→]n backbones with ∼10% branching at C-6 by terminal α-d-Glcp-(1→6)- or α-d-Glcp-(1→6)-α-d-Glcp-(1→6)- units, lower-molecular-mass linear β-d-glucans consisting of [→6)-β-d-Glcp-(1→]m sequences, and a lower-molecular-mass pentasaccharide-repeating α-l-fuco-α-d-galactan, {→6)-α-d-Galp-(1→6)-[α-l-Fucp-(1→2)-]α-d-Galp-(1→6)-α-d-Galp-(1→6)-α-d-Galp-(1→}p, were found to be present.