Lipopolysaccharide core region of Hafnia alvei: structure elucidation using chemical methods, gas chromatography-mass spectrometry, and NMR spectroscopy

Sugar and methylation analysis with the use of gas chromatography-mass spectrometry and 1H NMR spectroscopy proved that the core oligosaccharides isolated from lipopolysaccharides of eight Hafnia alvei strains have the identical hexasaccharide skeleton. However, 1H, 31P heterocorrelated spectra showed that the phosphorylation pattern is not the same. The branched heptose for the ATCC 13337, 1187, 2, 1191, 1196, 1220, and 481L strains is phosphorylated as in the following formula, where P = OP(O)(O−)2 and P-PEtN = [OP(O)(O−)]2O(CH2)2NH3+ A different phosphorylation pattern was found for the 1211 strain, where the branched heptose residue is 6-substituted by a monophosphorylethanolamine group, → 3(→ 7)(PEtN → 6)-α-LD-Hepp- (1 → 3) where PEtN = OP(O(O−)O(CH2)2NH3+.