The structure of the O-specific polysaccharide of Pseudomonas solanacearum strain 8089

✍ Scribed by Nina A. Kocharova; Alexander S. Shashkov; Yuriy A. Knirel; Lyudmila D. Varbanets; Natalya V. Moskalenko

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 287 KB
• Volume: 259
• Category: Article
• ISSN: 0008-6215
• DOI: 10.1016/0008-6215(94)84207-8

✦ Synopsis

Our structural study of the O-specific polysaccharide chains of the I? solunacearzm lipopolysaccharides [1,2] aims at the elucidation of the chemical basis for the classification of this phytopathogen. Now we describe the structure of the O-antigen polysaccharide of P. solanaceurum strain 8089. The O-specific polysaccharide was obtained by mild acid degradation of the lipopolysaccharide isolated from dried cells by the phenol-water procedure [31. The 13C NMR spectrum of the polysaccharide contained the signals for three anomeric carbons at 100.9, 103.0, and 103.9 ppm, one carbon bearing nitrogen (C-2 of GalN) at 51.8 ppm, two methyl groups of 6-deoxy sugars (C-6 of Rha) at 17.9 and 18.0 ppm, one hydroxymethyl group (C-6 of GalN) at 62.3 ppm, other sugar carbons in the region 68.7-79.8 ppm, and one N-acetyl group (Me at 23.3 ppm, CO at 175.8 ppm). The absence from the spectrum of signals for nonanomeric carbons at a field lower than 80 ppm characteristic for furanosides [4] proved that all monosaccharide residues are pyranoid. The coupling constants Jc_l,H_l determined from the gated-decoupling spectrum of the polysaccharide for all three sugar residues were relatively large (170-175 Hz) and indicative 151 of the (Y configuration of their glycosidic linkages. Correspondingly, in the 'H NMR spectrum of the polysaccharide (Fig. l), signals for three anomeric protons were present at 4.80, 5.05 (both d, Jr,, 1.5 Hz), and 5.19 ppm (d, Jr,, 4 Hz), two methyl groups of 6-deoxy sugars (H-6 of Rha) at * Corresponding author.