Studies on Fungal Polysaccharides. VIII. Extracellular Heteroglycans of Rhizopus nigricans

Main extracellular polysaccharide of R. nigricans, [α] D+68.1°, is a highly heterogenous glycan composed of fucose, mannose, glucose, galactose, N-acctylglucosamine, and Nacetylgalactosamine in a relative ratio of 1: 22: 4: 5: 3.8: 3.8. The results of periodate oxidation, Smith degradation, and partial acid hydrolysis indicate that the polysaccharide contains (1→2) and (1→4)-linked hexopyranose residues as the main linkages. The minor polysaccharide, [α] D-45.6°, is an acidic heteroglycan consistillg of fucose, galactose, and glucuronic acid, and its chemical structure is discussed.