The structure of the O-specific polysaccharide of the lipopolysaccharide from Pantoea agglomerans strain FL1

A neutral O-specific polysaccharide consisting of D-rhamnose was obtained by mild acid hydrolysis of the lipopolysac-charide of the plant pathogenic bacterium Pantoea agglomerans strain FL1, a common epiphyte of many plant species, and asso-ciated with Pseudomonas savastanoi pv. savastanoi in young and apparently intact olive knots. By means of compositional and methylation analyses, and NMR spectroscopy, the chemical repeating unit of the polymer was identified as a linear tetrasaccharide of the structure: →2)-α-D-Rhap-(1→2)-β-D-Rhap-(1→3)-α-D-Rhap-(1→2)-α-D-Rhap-(1→