The partial acid hydrolysis of a highly dextrorotatory fragment of the cell wall of Aspergillus niger. Isolation of the alpha-(1-3)-linked dextrin series.

1. A highly dextrorotatory polysaccharide (alpha(D)+232 degrees in n-sodium hydroxide), previously isolated as a fragment of Aspergillus niger cell walls, was prepared from whole mycelium and subjected to partial acid hydrolysis. 2. Fractionation of the hydrolysate on a charcoal column with a linear gradient of ethanol yielded a series of oligosaccharides. The disaccharide member was shown to be nigerose (3-O-alpha-d-glucopyranosyl-alpha-d-glucopyranose), although a small proportion of the disaccharide peak (10%) was present as maltose despite the fact that all the nigeran had been removed from the starting material. 3. The oligosaccharides forming the main peaks from the column were shown to be members of a polymer-homologous series (nigerodextrins) by (a) the relationship between the logarithm of their chromatographic mobility and degree of polymerization, (b) obeying the Freudenberg relationship, and (c) partial acid hydrolysis.