Structure of an acidic O-specific polysaccharide of Pseudoalteromonas haloplanktis type strain ATCC 14393 containing 2-acetamido-2-deoxy-D- and -L-galacturonic acids and 3-(N-acetyl-D-alanyl) amino-3, 6-dideoxy-D-glucose

摘要

An acidic O-specific polysaccharide was obtained from the lipopolysaccharide of Pseudoalteromonas haloplanktis ATCC 14393 and found to contain D-galactose, 3-(N-acetyl-D-alanyl) amino-3, 6-dideoxy-D-glucose (D-Qui3NdAlaAc), 2, 4-diacetamido-2, 4, 6-trideoxy-D-glucose (D-QuiNAc4NAc), 2-acetamido-2-deoxy-D- and -L-galacturonic acids (D- and L-GalNAcA), and O-acetyl groups. On the basis of Smith degradation and ~1H and ~(13)C NMR spectroscopic studies, including 2D, COSY, TOCSY, NOESY, ~1H, ~(13)C HMQC, and HMBC experiments, the following structure of the pentasaccharide repeating unit for the polysaccharide was established: -> 4)-#alpha#-L-GalpNAcA-(1 -> 3)-#beta#-D-QuipNAc4NAc-(1 -> 2)-#beta#-D-Quip3NDAlaAc-(1 -> 4)-#alpha#-D-GalpNAcA-(1 -> 4)-#alpha#-D-Galp2, 6Ac_2-(1 -> where O-acetylation of the galactose residue at each position is partial (50-70%).