The structure of the O-specific polysaccharide of Citrobacter O16 containing glycerol phosphate.
The O-specific polysaccharide, obtained by mild acid degradation of Citrobacter O16 lipopolysaccharide, consists of D-glucose, D-galactose, 2-acetamido-2-deoxy-D-galactose, glycerol and phosphate in the ratios 2:2:2:1:1. Selective cleavage of the polysaccharide was carried out by Smith degradation, N-deacetylation-deamination and dephosphorylation with 48% hydrofluoric acid, which was accompanied by unexpected splitting of one of the glycosidic linkages. The structures of the oligosaccharides thus obtained were established using 1H- and 13C-NMR spectroscopy, including one-dimensional NOE, two-dimensional rotating-frame NOE, homonuclear and heteronuclear 13C, 1H correlation spectroscopy, and, for the Smith degradation product, positive- and negative-ion-mode fast-atom-bombardment MS and MS/MS with collision-induced dissociation. On the basis of these data and the results of methylation analysis, it was concluded that the O-specific polysaccharide has the following repeating unit structure: [formula: see text]
Kocharova
N A
NA
N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow.
Thomas-Oates
J E
JE
Knirel
Y A
YA
Shashkov
A S
AS
Dabrowski
U
U
Kochetkov
N K
NK
Stanislavsky
E S
ES
Kholodkova
E V
EV
D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002247:Carbon Isotopes; D002954:Citrobacter / Q000737:chemistry* / Q000254:growth & development; D005994:Glycerophosphates / Q000032:analysis*; D009682:Magnetic Resonance Spectroscopy; D008745:Methylation; D008969:Molecular Sequence Data; D019081:O Antigens; D009844:Oligosaccharides / Q000737:chemistry* / Q000302:isolation & purification; D011135:Polysaccharides, Bacterial / Q000737:chemistry*; D016339:Spectrometry, Mass, Fast Atom Bombardment
D002247:Carbon Isotopes; D005994:Glycerophosphates; D019081:O Antigens; D009844:Oligosaccharides; D011135:Polysaccharides, Bacterial