An O-polysaccharide was prepared by mild acid hydrolysis of a lipopolysaccharide of Erwinia carotovora ssp. atroseptica GSPB 9205 and was found to contain a new higher branched monosaccharide, viz., 3,6,8-trideoxy-4-C-(R-1-hydroxyethyl)-D-gulo-octose, which we called erwiniose. The structure of the pentasaccharide repeating unit of the O-polysaccharide was established by monosaccharide analysis, including the determination of absolute configurations, methylation analysis, O-deacetylation, Smith degradation, and one- and two-dimensional NMR spectroscopy. The configuration of erwiniose was determined based on the coupling constants of vicinal protons combined with the nuclear Overhauser effect data and the results of periodate oxidation of the polysaccharide followed by reduction of the resultant 4-keto sugar (the C(1)—C(4)—C(1?)—C(2?) fragment) to give 3,6-dideoxy-D-ribo-hexose (paratose) and oxidation of 3-hydroxybutyraldehyde (the C(5)—C(8) fragment) to give R-3-hydroxybutyric acid.
Lipopolysaccharide, Erwinia, polysaccharide structure determination, higher branched monosaccharide
Publication DOI: 10.1007/s11172-005-0394-1Journal NLM ID: 7505544Publisher: Moscow: Nauka
Correspondence: knirel@ioc.ac.ru; avrid@gwgd.de
Institutions: N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, Russia, 119991 Moscow, Leninsky propekt, 47, George Avgust University, Institute of plant pathology and plant defence, Germany, Gettingen
Methods: methylation, NMR, sugar analysis, Smith degradation
Found