Structure of the O-specific polysaccharide from the lipopolysaccharide of Aeromonas hydrophila strain K691 containing 4-acetamido-4,6-dideoxy-d-glucose

Abstract

The O-specific polysaccharide (OPS) was isolated from the lipopolysaccharide of Aeromonas hydrophila strain K691 and studied by chemical methods and ¹H and ¹³C NMR spectroscopy, including 2D ¹H,¹H COSY, TOCSY, NOESY, ¹H-detected heteronuclear ¹H,¹³C HSQC, and HMBC experiments. It was found that the O-specific polysaccharide was built up of pentasaccharide repeating units composed of β-GlcpNAc, 2-O-acetylated α-Rhap, and β-Quip4NAc residues. The following structure of the OPS was established: →3)-α-l-Rha2OAc-(1→3)-β-d-GlcNAc-(1→3)-α-l-Rha2OAc-(1→3)-β-d-GlcNAc-(1→2)-β-d-Qui4NAc-(1→.

Keywords: 4-Amino-4,6-dideoxy-d-glucose; Aeromonas hydrophila; Fish pathogen; LPS; O-Acetylation; O-Antigen; O-specific polysaccharide.