The O-specific polysaccharide (OPS) was isolated from the lipopolysaccharide of Aeromonas veronii strain Bs8, which is pathogenic to common carp (Cyprinus carpio), after mild acid hydrolysis followed by gel-permeation chromatography. The high-molecular-mass OPS fraction was investigated using chemical methods, mass spectrometry, and 1H and 13C NMR spectroscopy techniques, including 2D homonuclear 1H,1H TOCSY, DQF COSY, NOESY, and heteronuclear 1H-detected 1H,13C HSQC, and HMBC experiments. The analysis revealed that the O-specific polysaccharide contains sugars with the galacto configuration of the ring and is composed of a disaccharide repeating unit with the following structure. (formula: see text).

LPS, O-antigen, O-specific polysaccharide, Aeromonas veronii, Fish pathogen, D-fucopyranose, D-Fucp, GalpNAc

13C NMR data:
Linkage	Residue	C1	C2	C3	C4	C5	C6
3	aDFucp	97.2	68.0	80.7	72.7	68.0	16.6
2	Ac	175.4	23.5
	bDGalpN	104.2	52.3	77.3	65.6	76.0	62.1


1H NMR data:
Linkage	Residue	H1	H2	H3	H4	H5	H6
3	aDFucp	5.04	3.88	3.88	4.06	4.00	1.24
2	Ac	-	2.05
	bDGalpN	4.70	4.10	3.81	4.16	3.69	3.80


1H/13C HSQC data:
Linkage	Residue	C1/H1	C2/H2	C3/H3	C4/H4	C5/H5	C6/H6
3	aDFucp	97.2/5.04	68.0/3.88	80.7/3.88	72.7/4.06	68.0/4.00	16.6/1.24
2	Ac		23.5/2.05
	bDGalpN	104.2/4.70	52.3/4.10	77.3/3.81	65.6/4.16	76.0/3.69	62.1/3.80

There is only one chemically distinct structure:

SVGMWSMILES3D molIonize

 

*O[C@H]1[C@@H](O)[C@@H](C)O[C@H](O[C@@H]2[C@@H](NC(C)=O)[C@H](*)O[C@H](CO)[C@@H]2O)[C@@H]1O

349.336 g/mol (C₁₄H₂₃R₂NO₉, R = next and previous repeats, not counted in mol weight)