Abstract
An acidic polysaccharide was isolated from the culture broth of Aureobasidium sp. K-1. The polysaccharide ([α]20D-10°) was composed of D-glucose and sulfoacetic acid. The glucan moiety was hydrolyzed by exo-β-1, 3-glucanase to give glucose and gentiobiose (molar ratio, ca. 1:3). The methylated glucan yielded on acid hydrolysis 2, 3, 4, 6-tetra-O-methyl-, 2, 4, 6-tri-O-methyl- and 2, 4- di-O-methyl-D-glucose (molar ratio, 2.6:1.0:2.7) together with small amounts of 2, 3, 6-tri-O-methyl- D-glucose. Smith degradation of the glucan moiety yielded glucose, glycerol and erythritol (molar ratio, 4:3.1:trace). From these results, it was suggested that the glucan consists of a backbone of β-1, 3-linked glucose residues containing single branches of glucose residues joined by β-1, 6-linkages, roughly three out of every four glucose residues in the backbone.
