Structural studies on the R-type lipopolysaccharide of Aeromonas hydrophila

摘要

A rough strain of Aeromonas hydrophila,AH-901,has an R-type lipopolysaccharide with the complete core.The following core structure was established by chemical degradations followed by sugar and methylation analyses along with ESIMS and NMR spectroscopy:D-alpha-D-Hep-(1->6)-D-alpha-D-Hep-(1->6)-beta-D-Glc-(1->4)-L-alpha-D-Hep-(1->5)-alpha-Kdo-(2-> where D-alpha-D-Hep and L-alpha-D-Hep stand for D-glycero- and L-glycero-alpha-D-manno-heptose,respectively;Kdo stands for 3-deoxy-D-manno-oct-2-ulosonic acid;all monosaccharides are in the pyranose form;the degree of substitution with beta-D-Gal is approx 50%.Lipid A of the lipopolysaccharide has a l,4'-bisphosphorylated beta-D-GlcN-(l->6)-alpha-D-GlcN disaccharide backbone with both phosphate groups substituted with 4-amino-4-deoxyarabinose residues.