| Autor: |
Wolfgang Nimmich, Bengt Lindberg, Ingemar Kvarnström, Per-Erik Jansson, Jörgen Lönngren, Frank Lindh, Per J. Garegg |
| Rok vydání: |
1980 |
| Předmět: |
|
| Zdroj: |
Carbohydrate Research. 78:127-132 |
| ISSN: |
0008-6215 |
| DOI: |
10.1016/s0008-6215(00)83666-6 |
| Popis: |
The configuration at the acetal carbon atom of pyruvic acid acetals present in some extracellular bacterial polysaccharides has been investigated. Assignment of the absolute configuration was made by comparing signals in the 13 C- and 1 H-n.m.r. spectra of the polysaccharides with those of model substances. The S -configuration was demonstrated in eight polysaccharides in which pyruvic acid is linked to O-4 and O-6 of D -glucopyranosyl or D -mannopyranosyl residues. The R -configuration was demonstrated in four polysaccharides in which pyruvic acid is linked to O-4 and O-6 of D -galactopyranosyl residues. Consequently, in each of these acetals, which form 1,3-dioxane rings, the methyl group is equatorial and the carboxyl group axial. The S -form was further demonstrated in four polysaccharides in which the pyruvic acid is linked to O-3 and O-4 of D -galactopyranosyl groups. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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