Structural determination of a 5-acetamido-3,5,7,9-tetradeoxy-7(3-hydroxybutyramido)-l-glycero-l-manno-nonulosonic acid-containing homopolysaccharide isolated from Sinorhizobium fredii HH103
Am. Gil-serrano et al., Structural determination of a 5-acetamido-3,5,7,9-tetradeoxy-7(3-hydroxybutyramido)-l-glycero-l-manno-nonulosonic acid-containing homopolysaccharide isolated from Sinorhizobium fredii HH103, BIOCHEM J, 342, 1999, pp. 527-535
The structure of a polysaccharide from Sinorhizobium fredii HH103 has been
determined. This polysaccharide was isolated by following the protocol for
lipopolysaccharide extraction. On the basis of monosaccharide analysis, met
hylation analysis, fast atom-bombardment MS, matrix-assisted laser desorpti
on ionization MS, electron-impact high-resolution MS, one-dimensional H-1-N
MR and C-13-NMR and two-dimensional NMR experiments. the structure was show
n to consist of a homopolymer of a 3:1 mixture of 5-acetamido-3,5,7,9-tetra
deoxy-7-[(R)- and (S)-3-hydroxybutyramido]-L-glycero-L-manno-nonulosonic ac
id. The sugar residues are attached via a glycosidic linkage to the OH grou
p of the 3-hydroxybutyramido substituent and thus the monomers are linked v
ia both glycosidic and amidic linkages. In contrast with the Sinorhizobium
K-antigens previously reported, which are composed of a disaccharide repeat
ing unit, the K-antigen polysacharide of S. fredii HH103 homopolysaccharide
.