The edible mushroom Albatrellus ovinus contains a α-L-fuco-α-D-galactan, α-D-glucan, a branched (1→6)-β-D-glucan and a branched (1→3)-β-D-glucan

Abstract

Albatrellus ovinus, the sheep polypore, is a large, dense mushroom being rich in cell wall material. Polysaccharides were isolated by sequential extraction, enzymatic treatment and analyzed with respect to monosaccharide composition, glycosidic linkages by methylation and GC-MS as well as NMR spectroscopy. A fucogalactan composed of an (1→6)-α-D-galactan backbone with single α-L-Fucp residues attached at O-2 was identified in the hot water extract obtained after treatment with a protease and size exclusion chromatography. Both the hot water extract and the hot alkali extract contained an (1→4)-α-D-glucan whereas β-D-glucans were mainly present in the latter. Structural analysis suggested the presence of two different β-D-glucan backbone structures; a (1→6)-linked β-D-glucan with single β-D-Glcp residues at O-3 and also a (1→3)-linked β-D-glucan with branches in O-6. In addition there were identified short (1→2)-linked β-D-xylan and (1→3)-α-D-mannan chains.