title: The chemical structure of the lipid A component of lipopolysaccharides from Chromobacterium violaceum NCTC 9694.
abstract: The chemical structure of the lipid A component of lipopolysaccharides from Chromobacterium violaceum NCTC9694 was studied. Sequential treatment of lipopolysaccharide with alkali, acid, sodium borohydride and hydrazine allowed the isolation of a reduced glucosamine disaccharide. According to methylation studies and enzymic analysis with beta-N-acetylglucosaminidase the D-glucosamine residues are beta(1 leads to 6) linked. The disaccharide carries two phosphate groups, one being linked glycosidically, the other being linked as an ester to the non-reducing glucosamine. Application of a different degradation pathway shows that the ester-bound phosphate group is substituted by a 4-aminoarabinosyl residue and that the glycosidically linked phosphate group is substituted by a glucosaminyl residue. Neither the amino nor the hydroxyl groups of both these substituents are acylated. This backbone structure is shown in the following formula: (formula: see text). The amino groups of the central glucosamine disaccharide are substituted by D-3-hydroxy-dodecanoic acid, the hydroxyl groups by dodecanoic, L-2-hydroxydodecanoic and D-3-hydroxy-decanoic acid.
mesh_terms: D000117:Acetylglucosamine / Q000032:analysis; D000118:Acetylglucosaminidase; D002849:Chromatography, Gas; D002861:Chromobacterium / Q000032:analysis*; D005231:Fatty Acids, Unsaturated / Q000032:analysis; D005944:Glucosamine / Q000032:analysis; D008050:Lipid A / Q000302:isolation & purification; D008070:Lipopolysaccharides / Q000302:isolation & purification; D013058:Mass Spectrometry
chemical_list: D005231:Fatty Acids, Unsaturated; D008050:Lipid A; D008070:Lipopolysaccharides; D000118:Acetylglucosaminidase; D005944:Glucosamine; D000117:Acetylglucosamine