The structure of the phenol-soluble polysaccharide from Shewanella putrefaciens strain A6 has been elucidated. Chemical modifications of the polymer in conjunction with 1H and 13C NMR spectroscopy, including 2D techniques, were employed in the analysis. It is concluded that the repeating unit is composed of two nine-carbon sugars as follows: →4)-α-NonpA-(2→3)-β-Sugp-(1→ where α-NonpA is 5-acetamido-7-acetamidino-8-O-acetyl-3,5,7,9-tetradeoxy-L-glycero-α-D-galacto-non-2-ulosonic acid (8eLeg) and β-Sugp is 2-acetamido-2,6-dideoxy-4-C-(3'-carboxamide-2',2'-dihydroxypropyl)-β-D-galactopyranose, with the proposed name Shewanellose (She).

biosynthesis, polysaccharide, NMR spectroscopy, nonulosonic acid, shewanellose, Shewanella putrefaciens

13C NMR data:
Linkage	Residue	C1	C2	C3	C4	C5	C6	C7	C8	C9
3,5	Ac	175.0	23.8
3,7	Am	168.0	20.3
3,8	Ac	174.6	21.8
3	aX8eLegp	176.5	99.6	42.5	77.0	51.8	74.1	57.8	73.3	17.3
	bXShewanellosep	104.4	51.8	85.2	79.4	75.7	15.5	48.9	105.8	177.9


1H NMR data:
Linkage	Residue	H1	H2	H3	H4	H5	H6	H7	H8	H9
3,5	Ac	-	2.00
3,7	Am	?	2.02
3,8	Ac	-	2.02
3	aX8eLegp	-	-	1.74-2.76	3.55	3.67	4.62	3.73	5.14	1.35
	bXShewanellosep	4.46	4.13	3.88	-	3.80	1.18	2.24-2.33	-	-


1H/13C HSQC data:
Linkage	Residue	C1/H1	C2/H2	C3/H3	C4/H4	C5/H5	C6/H6	C7/H7	C8/H8	C9/H9
3,5	Ac		23.8/2.00
3,7	Am	168.0/?	20.3/2.02
3,8	Ac		21.8/2.02
3	aX8eLegp			42.5/1.74-2.76	77.0/3.55	51.8/3.67	74.1/4.62	57.8/3.73	73.3/5.14	17.3/1.35
	bXShewanellosep	104.4/4.46	51.8/4.13	85.2/3.88		75.7/3.80	15.5/1.18	48.9/2.24-2.33		

There is only one chemically distinct structure:

SVGMWSMILES3D molIonize

 

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

629.62 g/mol (C₂₆H₃₉R₂N₅O₁₃, R = next and previous repeats, not counted in mol weight)

The structure of the phenol-soluble polysaccharide from Shewanella putrefaciens strain A6 has been elucidated. Chemical modifications of the polymer in conjunction with 1H and 13C NMR spectroscopy, including 2D techniques, were employed in the analysis. It is concluded that the repeating unit is composed of two nine-carbon sugars as follows: →4)-α-NonpA-(2→3)-β-Sugp-(1→ where α-NonpA is 5-acetamido-7-acetamidino-8-O-acetyl-3,5,7,9-tetradeoxy-L-glycero-α-D-galacto-non-2-ulosonic acid (8eLeg) and β-Sugp is 2-acetamido-2,6-dideoxy-4-C-(3'-carboxamide-2',2'-dihydroxypropyl)-β-D-galactopyranose, with the proposed name Shewanellose (She).

biosynthesis, polysaccharide, NMR spectroscopy, nonulosonic acid, shewanellose, Shewanella putrefaciens

There is only one chemically distinct structure:

SVGMWSMILES3D molIonize

 

CO[C@@H]1O[C@@](CC(=O)C(N)=O)([C@@H](C)O)[C@H](O[C@]2(C(=O)O)C[C@H](O)[C@@H](NC(C)=O)[C@H]([C@H](NC(C)=N)[C@H](C)OC(C)=O)O2)[C@H]1NC(C)=O

661.662 g/mol (C₂₇H₄₃N₅O₁₄)

The chemical structures of polysaccharides and LPS core oligosaccharides, isolated from various Gram-negative marine bacteria from the genera Pseudoalteromonas and Shewanella belonging to the Alteromonadaceae family and gamma-subclass of Proteobacteria, are reviewed. The polysaccharides are distinguished by the acidic character (e.g., due to the presence of hexuronic and aldulosonic acids and their derivatives) and the occurrence of unusual sugars, including N-acyl derivatives of 6-deoxyamino sugars, such as N-acetyl-D-quinovosamine, N-acetyl-L-fucosamine and N-acetyl-6-deoxy-L-talosamine, and higher sugars like 2,6-dideoxy-2-acetamido-4-C-(3'-carboxamide-2',2'-dihydroxypropyl)-D-galac topyranose (shewanellose). Many constituent sugars have various uncommon non-sugar substituents, such as alanine, formic, lactic and hydroxybutyric acids, sulfate, phosphate, and 2-aminopropane-1,3-diol.

Lipopolysaccharide, oligosaccharide structure, O-antigen, polysaccharide structure, Shewanella, Pseudoalteromonas, Proteobacteria

There is only one chemically distinct structure:

SVGMWSMILES3D molIonize

 

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

629.62 g/mol (C₂₆H₃₉R₂N₅O₁₃, R = next and previous repeats, not counted in mol weight)

This chapter provides an overview of the chemistry of 5,7-diamino-3,5,7,9-tetradeoxynon-2-ulosonic acids in bacterial glycopolymers. Ald-2-ulosonic acids are the important components of natural glycoconjugates. Sialic acids—namely, N- and O-acyl derivatives of 5-amino-3,5-dideoxy-D-glycero-D-galacto-non-2-ulosonic acid (neuraminic acid, Neu), generally occur in glycoconjugates of vertebrates and play a significant role in their recognition, regulation, and protection. A deamino analogue of neuraminic acid—3-deoxy-D-glycero-D-galacto-non-2-ulosonic acid (Kdn)—has also been found in a variety of animal tissues. 3-Deoxy-D-manno-oct-2-ulosonic acid (Kdo) is an essential component of lipopolysaccharides (LPSs) of Gram-negative bacteria that functions to link the carbohydrate portion to the lipid moiety. In rare cases, Kdo in LPS is replaced with a 3-hydroxylated analogue—D-glycero-D-talo-oct-2-ulosonic acid. The chapter focuses on the occurrence and characterization of derivatives of 5,7-diamino-3,5,7,9-tetradeoxynon-2-ulosonic acids and presents experimental approaches that are used to identify them and to elucidate the structures of the bacterial polysaccharides that contain the nonulosonic acids. It also presents the recent data on the biosynthesis of these sugars and discusses their role in immune recognition.

Lipopolysaccharide, LPS, structure, polysaccharide, Bacterial polysaccharide, 5, 7-diamino-3, 7, higher sugar, 9-tetradeoxynonulosonic acid

There is only one chemically distinct structure:

SVGMWSMILES3D molIonize

 

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

629.62 g/mol (C₂₆H₃₉R₂N₅O₁₃, R = next and previous repeats, not counted in mol weight)