The specific capsular antigen of Streptococcus pneumoniae serotype 35B was shown by a combination of 2D NMR methods and mass spectrometric and classical carbohydarate chemical techniques to be a high molecular weihgt polymer containing D-galactose, D-glucose, 2-acetamido-2deoxy-D-galactose, and ribitol (2:1:1:1). The polysaccharide repeating unit is polymerized through phosphate diester linkages to give the structure {structure}. Seventy persent of the bDGalf residues glycosidically linked to the ribitol units carry an O-acetyl sustituent.

antigen, structure, capsular, characterization, K-antigen, polysaccharide, serotype, Streptococcus, Streptococcus pneumoniae

13C NMR data:
Linkage	Residue	C1	C2	C3	C4	C5	C6
1,6	bDGlcp	103.0	73.4	75.9	69.8	76.0	60.9
1	bDGalf	105.5	83.9	75.8	84.0	69.5	71.2
	xDRib-ol	68.3	70.4	72.2	72.2	62.7


1H NMR data:
Linkage	Residue	H1	H2	H3	H4	H5	H6
1,6	bDGlcp	4.51	3.34	3.50	3.40	3.47	3.74-3.93
1	bDGalf	5.18	4.96	4.25	4.09	4.04	3.78-4.08
	xDRib-ol	3.74-3.85	3.98	3.73	3.83	3.67-3.82


1H/13C HSQC data:
Linkage	Residue	C1/H1	C2/H2	C3/H3	C4/H4	C5/H5	C6/H6
1,6	bDGlcp	103.0/4.51	73.4/3.34	75.9/3.50	69.8/3.40	76.0/3.47	60.9/3.74-3.93
1	bDGalf	105.5/5.18	83.9/4.96	75.8/4.25	84.0/4.09	69.5/4.04	71.2/3.78-4.08
	xDRib-ol	68.3/3.74-3.85	70.4/3.98	72.2/3.73	72.2/3.83	62.7/3.67-3.82

There is only one chemically distinct structure:

SVGMWSMILES3D molIonize

 

OC[C@H]1O[C@@H](OC[C@@H](O)[C@@H]2O[C@@H](OC[C@H](O)[C@H](O)[C@H](O)CO)[C@H](O)[C@H]2O)[C@H](O)[C@@H](O)[C@@H]1O

476.428 g/mol (C₁₇H₃₂O₁₅)