STRUCTURE OF A DECASACCHARIDE ISOLATED BY MILD ACID DEGRADATION AND DEPHOSPHORYLATION OF THE LIPOPOLYSACCHARIDE OF PSEUDOMONAS FLUORESCENS STRAIN ATCC 49271

摘要

Mild acid degradation of the Pseudomonas fluorescens strain ATCC 49271 lipopolysaccharide resulted in a core oligosaccharide containing D-glucose, 2-acetamido-2-deoxy-D-glucose, 2-(L-alanylamino)-2-deoxy-D-galactose, 2-acetamido-2,6-dideoxy-D-glucose (QuiNAc), 2-acetamido-2,6-dideoxy-L-galactose (FucNAc), L-glycero-D-manno-heptose (Hep), 3-deoxy-D-manno-octulosonic acid (Kdo, present in multiple forms), and 5-acetamidino-7-acetamido-3,5,7,9-tetradeoxy-L-glycero-D-galacto-nonuloson ic acid (a di-N-acyl derivative of legionaminic acid, Non) as well as O-acetyl, O-carbamoyl, and phosphate groups, including triphosphate groups. The dephosphorylated (HF) decasaccharide and products of its partial and full O-deacylation were studied by methylation analysis, GLC-MS, and H-1 NMR spectroscopy, including 1D NOE and 2D shift-correlated spectroscopy (COSY). The core oligosaccharide of P. fluorescens strain ATCC 49271 was found to be a decasaccharide (with partially degraded Kdo region) and one O-antigen repeating unit (di-N-acyllegionaminic acid, Non) attached, The following structure of the dephosphorylated core oligosaccharide was established: [GRAPHICS] [References: 26]