Abstract
A specific layer at the outermost surface of mycelia of Glomerella cingulata G 4-1-4 was observed. The substance isolated from this layer was a polysaccharide ([α]20D +82.6°C) composed of o-mannose (97.6%), protein (2.0%) and a trace amount of phosphate. A high proportion of 3, 4-di-O-methylmannose (38mol%) was found on methylation analysis. Digestion of this mannan with a bacterial α-D-mannosidase released 78% of the D-mannose. In addition, the results of acetolysis, partial acid hydrolysis, and 1H- and 13C-NMR spectroscopy showed that the G. cingulata G 4-1-4 mannan has a backbone joined by α-l, 6-linkages, and α-1, 2- and 1, 3-linked mannose residues are attached to the C-2 position of the main chain segment, giving it a highly branched structure. Although G. cingulata G 4-1-4 mannan has the above properties, its basic structure appears to be similar to that of baker's yeast mannan.
