A marine bacterium Pseudoalteromonas sp. KMM 634 produces a highly acidic, regular O-specific polysaccharide, containing D-glucuronic acid (D-GlcA), 2,3-diacetamido-2,3-dideoxy-D-glucuronic acid (D-GlcNAc3NAcA), 2,3-diacetamido-2,3-dideoxy-D-mannuronoyl-L-alanine (D-ManNAc3NAcA6Ala) and 2-acetamido-2,4,6-trideoxy-4-[(S)-3-hydroxybutyramido]-D-glucose (D-QuiNAc4NAcyl). The polysaccharide was stable towards solvolysis with anhydrous HF but could be partially depolymerised by triflic acid. This new reagent for selective cleavage of carbohydrates split primarily 1,2-trans-β-glycosidic linkages and did not affect amide-linked substituents. As a result, a disaccharide and a trisaccharide with a GlcNAc3NAcA residue at the reducing end were obtained. Based on these data and studies of the initial polysaccharide and derived oligosaccharides by two-dimensional NMR spectroscopy, the following structure of the tetrasaccharide repeating unit was established: →3)-a-D-QuipNAc4NAcyl-(1→4)-b-D-ManpNAc3NAcA6Ala-(1→4)-b-D-GlcpNAc3NAcA-(1→4)-b-D-GlcpA-(1→.

structure, O-specific polysaccharide, Pseudoalteromonas haloplanktis, cleavage, triflic acid solvolysis

13C NMR data:
Linkage	Residue	C1	C2	C3	C4	C5	C6
4,4,4,2	Ac
4,4,4,4	lS3HOBut	?	46.4	66.4	23.7
4,4,4	aDQuipN4N	97.9	54.4	77.9	56.2	68.9	18.2
4,4,2	Ac
4,4,3	Ac
4,4,6	xLAla?	?	51.0	18.8
4,4	bDManpN3NA	100.1	52.7	54.4	70.1	77.8	?
4,2	Ac
4,3	Ac
4	bDGlcpN3NA	102.8	54.4	54.4	79.1	76.5	?
	bDGlcpA	104.8	73.6	75.0	82.0	75.8	?


1H NMR data:
Linkage	Residue	H1	H2	H3	H4	H5	H6
4,4,4,2	Ac
4,4,4,4	lS3HOBut	-	2.37	4.13	1.24
4,4,4	aDQuipN4N	5.12	4.11	3.78	3.68	3.51	1.12
4,4,2	Ac
4,4,3	Ac
4,4,6	xLAla?	-	4.37	1.51
4,4	bDManpN3NA	4.89	4.33	4.35	4.03	4.06	-
4,2	Ac
4,3	Ac
4	bDGlcpN3NA	4.70	3.92	3.99	3.90	4.04	-
	bDGlcpA	4.43	3.25	3.63	3.78	3.87	-


1H/13C HSQC data:
Linkage	Residue	C1/H1	C2/H2	C3/H3	C4/H4	C5/H5	C6/H6
4,4,4,2	Ac
4,4,4,4	lS3HOBut		46.4/2.37	66.4/4.13	23.7/1.24
4,4,4	aDQuipN4N	97.9/5.12	54.4/4.11	77.9/3.78	56.2/3.68	68.9/3.51	18.2/1.12
4,4,2	Ac
4,4,3	Ac
4,4,6	xLAla?		51.0/4.37	18.8/1.51
4,4	bDManpN3NA	100.1/4.89	52.7/4.33	54.4/4.35	70.1/4.03	77.8/4.06	
4,2	Ac
4,3	Ac
4	bDGlcpN3NA	102.8/4.70	54.4/3.92	54.4/3.99	79.1/3.90	76.5/4.04	
	bDGlcpA	104.8/4.43	73.6/3.25	75.0/3.63	82.0/3.78	75.8/3.87	

The spectrum also has 5 signals at unknown positions (not plotted).

There is only one chemically distinct structure:

SVGMWSMILES3D molIonize

 

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

1035.964 g/mol (C₄₁H₆₁R₂N₇O₂₄, R = next and previous repeats, not counted in mol weight)

A marine bacterium Pseudoalteromonas sp. KMM 634 produces a highly acidic, regular O-specific polysaccharide, containing D-glucuronic acid (D-GlcA), 2,3-diacetamido-2,3-dideoxy-D-glucuronic acid (D-GlcNAc3NAcA), 2,3-diacetamido-2,3-dideoxy-D-mannuronoyl-L-alanine (D-ManNAc3NAcA6Ala) and 2-acetamido-2,4,6-trideoxy-4-[(S)-3-hydroxybutyramido]-D-glucose (D-QuiNAc4NAcyl). The polysaccharide was stable towards solvolysis with anhydrous HF but could be partially depolymerised by triflic acid. This new reagent for selective cleavage of carbohydrates split primarily 1,2-trans-β-glycosidic linkages and did not affect amide-linked substituents. As a result, a disaccharide and a trisaccharide with a GlcNAc3NAcA residue at the reducing end were obtained. Based on these data and studies of the initial polysaccharide and derived oligosaccharides by two-dimensional NMR spectroscopy, the following structure of the tetrasaccharide repeating unit was established: →3)-a-D-QuipNAc4NAcyl-(1→4)-b-D-ManpNAc3NAcA6Ala-(1→4)-b-D-GlcpNAc3NAcA-(1→4)-b-D-GlcpA-(1→.

structure, O-specific polysaccharide, Pseudoalteromonas haloplanktis, cleavage, triflic acid solvolysis

There is only one chemically distinct structure:

SVGMWSMILES3D molIonize

 

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

605.554 g/mol (C₂₃H₃₅N₅O₁₄)

A marine bacterium Pseudoalteromonas sp. KMM 634 produces a highly acidic, regular O-specific polysaccharide, containing D-glucuronic acid (D-GlcA), 2,3-diacetamido-2,3-dideoxy-D-glucuronic acid (D-GlcNAc3NAcA), 2,3-diacetamido-2,3-dideoxy-D-mannuronoyl-L-alanine (D-ManNAc3NAcA6Ala) and 2-acetamido-2,4,6-trideoxy-4-[(S)-3-hydroxybutyramido]-D-glucose (D-QuiNAc4NAcyl). The polysaccharide was stable towards solvolysis with anhydrous HF but could be partially depolymerised by triflic acid. This new reagent for selective cleavage of carbohydrates split primarily 1,2-trans-β-glycosidic linkages and did not affect amide-linked substituents. As a result, a disaccharide and a trisaccharide with a GlcNAc3NAcA residue at the reducing end were obtained. Based on these data and studies of the initial polysaccharide and derived oligosaccharides by two-dimensional NMR spectroscopy, the following structure of the tetrasaccharide repeating unit was established: →3)-a-D-QuipNAc4NAcyl-(1→4)-b-D-ManpNAc3NAcA6Ala-(1→4)-b-D-GlcpNAc3NAcA-(1→4)-b-D-GlcpA-(1→.

structure, O-specific polysaccharide, Pseudoalteromonas haloplanktis, cleavage, triflic acid solvolysis

There is only one chemically distinct structure:

SVGMWSMILES3D molIonize

 

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

877.855 g/mol (C₃₅H₅₅N₇O₁₉)