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.