The structure of the O-polysaccharide of the lipopolysaccharide from a diarrheal strain isolated in Bangladesh was studied with sugar, and methylation analysis, NMR spectroscopy, mass spectrometry and partial acid hydrolysis. The strain was first designated as Hafnia alvei, but later found to be a possible new species in the genus Escherichia. Two different polysaccharides were detected, a major and a minor one. The structure of the major polysaccharide is given below, while the structure of the minor one was not investigated. The structure of the repeating unit was established as The structure does not resemble any of the previously investigated lipopolysaccharide O-chains from Escherichia coli or H. alvei, but could fit in either group based on types of sugar residues and acidity. Phenotypic microbiological studies cannot definitely assign it to either species of the two genera. Genetic hybridization studies indicate that the Bangladeshi isolates may require a new species designation under the genus Escherichia

Lipopolysaccharide, Escherichia coli, Hafnia alvei, diarrhea, neuraminic acid

13C NMR data:
Linkage	Residue	C1	C2	C3	C4	C5	C6	C7	C8	C9
3,3	bDGalf	109.9	82.8	77.8	83.8	70.6	72.1
3,2	Ac	175.8	22.8
3	bDGalpN	103.7	52.4	78.8	68.5	75.6	61.7
6,5	Ac	175.8	22.8
6	aXNeup	174.2	101.2	41.0	69.0	52.6	73.8	69.0	72.4	63.4
	bDGalp	104.2	70.6	82.8	69.0	73.4	64.1


1H NMR data:
Linkage	Residue	H1	H2	H3	H4	H5	H6	H7	H8	H9
3,3	bDGalf	5.11	4.09	4.05	4.04	4.00	3.89
3,2	Ac	-	2.05
3	bDGalpN	4.73	4.04	3.83	4.07	3.70	3.75
6,5	Ac	-	2.05
6	aXNeup	-	-	1.68-2.74	3.74	3.84	3.70	3.78	4.03	?
	bDGalp	4.43	3.65	3.72	4.19	3.73	3.62-3.92


1H/13C HSQC data:
Linkage	Residue	C1/H1	C2/H2	C3/H3	C4/H4	C5/H5	C6/H6	C7/H7	C8/H8	C9/H9
3,3	bDGalf	109.9/5.11	82.8/4.09	77.8/4.05	83.8/4.04	70.6/4.00	72.1/3.89
3,2	Ac		22.8/2.05
3	bDGalpN	103.7/4.73	52.4/4.04	78.8/3.83	68.5/4.07	75.6/3.70	61.7/3.75
6,5	Ac		22.8/2.05
6	aXNeup			41.0/1.68-2.74	69.0/3.74	52.6/3.84	73.8/3.70	69.0/3.78	72.4/4.03	63.4/?
	bDGalp	104.2/4.43	70.6/3.65	82.8/3.72	69.0/4.19	73.4/3.73	64.1/3.62-3.92

There is only one chemically distinct structure:

SVGMWSMILES3D molIonize

 

*OC[C@@H](O)[C@@H]1O[C@@H](O[C@@H]2[C@@H](NC(C)=O)[C@H](O[C@@H]3[C@@H](O)[C@H](*)O[C@H](CO[C@]4(C(=O)O)C[C@H](O)[C@@H](NC(C)=O)[C@H]([C@H](O)[C@H](O)CO)O4)[C@@H]3O)O[C@H](CO)[C@@H]2O)[C@H](O)[C@H]1O

818.732 g/mol (C₃₁H₅₀R₂N₂O₂₃, R = next and previous repeats, not counted in mol weight)