Plesiomonasshigelloides strain CNCTC 110/92 (O51) was identified as a new example of plesiomonads synthesising lipopolysaccharides (LPSs) that show preference for a non-aqueous surrounding during phenol/water extraction. Chemical analyses combined with (1)H and (13)C NMR spectroscopy, MALDI-TOF and ESI mass spectrometry showed that the repeating units of the O-specific polysaccharides isolated from phenol and water phase LPSs of P. shigelloides O51 have the same structure: →4)-β-D-GlcpNAc3NRA-(1→4)-α-L-FucpAm3OAc-(1→3)-α-D-QuipNA c-(1→, containing the rare sugar constituent 2,3-diamino-2,3-dideoxyglucuronic acid (GlcpNAc3NRA), and substituents such as D-3-hydroxybutyric acid (R) and acetamidino group (Am). The HR-MAS NMR spectra obtained for the isolated LPSs and directly on bacteria indicated that the O-acetylation pattern was consistent throughout the entire preparation. The (1)H chemical shift values of the structure reporter groups identified in the isolated O-antigens matched those present in bacteria. We have found that the O-antigens recovered from the phenol phase showed a higher degree of polymerisation than those isolated from the water phase.

polysaccharide, endotoxin, Plesiomonas shigelloides, lipopolysaccharideO-antigen, high resolution magic angle spinninig NMR

13C NMR data:
Linkage	Residue	C1	C2	C3	C4	C5	C6
3,4,2	Ac	175.2	23.0
3,4,3	lR3HOBut	174.0	45.8	65.7	22.8
3,4	bDGlcpN3NA	103.2	55.0	54.8	73.1	79.2	175.0
3,2	Am	166.8	19.7
3,3	Ac	173.9	21.0
3	aLFucpN	96.4	51.1	71.2	78.0	67.4	15.9
2	Ac	174.2	22.9
	aDQuipN	96.5	54.0	76.5	74.2	68.8	17.4


1H NMR data:
Linkage	Residue	H1	H2	H3	H4	H5	H6
3,4,2	Ac	-	1.98
3,4,3	lR3HOBut	-	2.27-2.29	4.06	1.15
3,4	bDGlcpN3NA	4.60	3.84	4.24	3.98	3.76	-
3,2	Am	?	2.24
3,3	Ac	-	2.08
3	aLFucpN	5.11	4.22	5.05	4.14	4.50	1.17
2	Ac	-	1.96
	aDQuipN	5.08	4.03	3.69	3.22	3.78	1.24


1H/13C HSQC data:
Linkage	Residue	C1/H1	C2/H2	C3/H3	C4/H4	C5/H5	C6/H6
3,4,2	Ac		23.0/1.98
3,4,3	lR3HOBut		45.8/2.27-2.29	65.7/4.06	22.8/1.15
3,4	bDGlcpN3NA	103.2/4.60	55.0/3.84	54.8/4.24	73.1/3.98	79.2/3.76	
3,2	Am	166.8/?	19.7/2.24
3,3	Ac		21.0/2.08
3	aLFucpN	96.4/5.11	51.1/4.22	71.2/5.05	78.0/4.14	67.4/4.50	15.9/1.17
2	Ac		22.9/1.96
	aDQuipN	96.5/5.08	54.0/4.03	76.5/3.69	74.2/3.22	68.8/3.78	17.4/1.24

There is only one chemically distinct structure:

SVGMWSMILES3D molIonize

 

*O[C@@H]1[C@@H](C(=O)O)O[C@@H](O[C@@H]2[C@H](C)O[C@@H](O[C@@H]3[C@@H](NC(C)=O)[C@@H](*)O[C@H](C)[C@H]3O)[C@@H](NC(C)=N)[C@@H]2OC(C)=O)[C@H](NC(C)=O)[C@H]1NC(=O)C[C@@H](C)O

717.726 g/mol (C₃₀H₄₇R₂N₅O₁₅, R = next and previous repeats, not counted in mol weight)