Structural studies on Shigella flexneri serotype 6 core region.

The core structure of Shigella flexneri serotype 6 has been investigated. The methods used in these studies involved methylation analysis, periodate oxidation, Smith degradation and enzymic modifications of core oligosaccharides isolated from two smooth strains and four rough mutants. As a result the complete core region was established (Formula: see text) where DGalp = D-galactopyranose, DGlcp = D-glucopyranose, L alpha DHepp = L-glycero-D-mannoheptapyranose, dOclA = 3-deoxy-D-manno-octulosonic, DGlcNp = 2-amino-2-deoxy-D-glucopyranose and P--PEtN = pyrophosphorylethanolamine (partially substituted). In the R mutants examined two types of mutation have been observed: (1) defect in heptose region (lack of D-glucosamine) or (2) defects in hexose region of the core.