Structural analysis of the specific capsular polysaccharide of Rhodococcus equi serotype 2
1990; Elsevier BV; Volume: 206; Issue: 2 Linguagem: Inglês
10.1016/0008-6215(90)80070-j
ISSN1873-426X
AutoresWayne B. Severn, J C S Richards,
Tópico(s)Legume Nitrogen Fixing Symbiosis
ResumoThe specific capsular polysaccharide produced by Rhodococcus equi serotype 2 is a high-molecular-weight acidic polymer composed of D-glucose, D-mannose, D-glucuronic acid and 3-O-[(S)-1-carboxyethyl]-L-rhamnose in equimolar proportions. Structural analysis, employing a combination of chemical and n.m.r. techniques, established that the polysaccharide is composed of linear repeating tetrasaccharide units. (formula; see text) in which the beta-D-mannose residues carry O-acetyl groups at O-2 and O-3 to the extent of 1.7 mol equivalents. Unequivocal determination of the absolute chirality of the 3-O-[(S)-1-carboxyethyl]-alpha-L-rhamnose residues was achieved by chemical correlation with an authentic synthetic sample. The 1H and 13C-n.m.r. resonances of the native and O-deacetylated serotype 2 polysaccharides were fully assigned by homo- and heteronuclear chemical-shift correlation methods.
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