Structure of the O-polysaccharide of Pseudomonas syringae pv. delphinii NCPPB 1879T Having Side Chains of 3-Acetamido-3,6-dideoxy-D-galactose Residues
E. L. Zdorovenko1, G. V. Zatonsky1, N. A. Kocharova1, A. S. Shashkov1, Y. A. Knirel1*, and V. V. Ovod2
1Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky pr. 47, Moscow, 119991 Russia; fax: (095) 135-5328; E-mail: knirel@ioc.ac.ru2Institute of Medical Technology, University of Tampere, 33101 Tampere, P.O. Box 607, Finland; fax: (358-3) 215-7332; E-mail: ltvlov@uta.fi
* To whom correspondence should be addressed.
Received April 6, 2001
The O-polysaccharide (OPS) was obtained from the lipopolysaccharide of Pseudomonas syringae pv. delphinii NCPPB 1879T and studied by sugar and methylation analyses, Smith degradation, and 1H- and 13C-NMR spectroscopy. The OPS was found to contain residues of L-rhamnose (L-Rha) and 3-acetamido-3,6-dideoxy-D-galactose (D-Fuc3NAc), and the following structure of the major (n = 2) and minor (n = 3) heptasaccharide repeating units of the OPS was established:
The OPS is distinguished by the presence of oligosaccharide side chains consisting of three D-Fuc3NAc residues that are connected to each other by the (alpha1-->2)-linkage. The OPS is characterized by a structural heterogeneity due to a different position of substitution of one of the four L-rhamnose residues in the main chain of the repeating unit as well as to the presence of oligosaccharide units with an incomplete side chain.
KEY WORDS: Pseudomonas syringae, O-specific polysaccharide, lipopolysaccharide, 3-acetamido-3,6-dideoxy-D-galactose
