The structures of two glucans from yeast‐cell walls

Abstract

On the basis of methylation, periodate oxidation and enzymic degradation studies, Manners and Patterson [ 1,2] suggested that yeast glucan was a branched polysaccharide consisting of main chains of p-(+6)linked D-glucose residues to which linear side chains of /3-( l-3)-linked D-glucose residues were attached. A structure of the same general type, but differing in some details, has been proposed independently by Misaki and his co-workers [3, Both of these structur-es differed significantly from those suggested previously by Bell and Northcote [5] and by Peat and his co-workers The former suggested that yeast gi..._,n was highly branched, and had fl-( l-+2)-interchain linkages whilst the latter proposed a linear structure containing certain sequences of p41+3)-and P-(+6)-linked D-glucose residues. Bacon and Farmer [ 71 have recently suggested that these differences in structure arise, in part, from the heterogeneous nature of yeast glucan, and that it is, in fact, a mixture of two polysaccharides. The minor component of this mixture was identified by infrared spectroscopy as a p (l-+6)-glucan. We now report confirmation of this suggestion, and chemical evidence for the structures of the two glucans.