Structure of the O3 antigen of Stenotrophomonas (Xanthomonas or Pseudomonas) maltophilia

The O antigen isolated from the lipopolysaccharide of a strain of Stenotrophomonas (Xanthomonas or Pseudomonas) maltophilia serogroup O3 was found to contain 4-acetamido-4,6-dideoxy-d-galactose, d-fucose, and N-acetyl-d-glucosamine. By means of chemical degradations and NMR spectroscopy the repeating unit of the O-specific polymer was determined to be a branched trisaccharide repeating-unit of the structure shown.