Abstract: | Two oligosaccharides were isolated from a partial hydrolysis of the lipopolysaccharide from Shigella dysenteriae which had a common antigen with human red blood cells (RBC). A disaccharide sh-2 had a structure of O-β-D-galactosyl-(l→2)-D-galactose, and was active in the hemagglutination inhibition test between human O RBC and anti-S. dysenteriae chicken serum. A tetrasaccharide sh-12 was composed of galactose and rhamnose and was a more effective inhibitor than sh-2. Both oligosaccharides were assumed to be derived from the determinant structure of a common antigen. Serological specificity of the hemagglutinin in chicken serum was examined using these oligosaccharides and human milk oligosaccharides, and the 1→2 linked galactosyl residue was supposed to be important for determination of the heterophile RBC antigenicity. |