The molecule is an amino octasaccharide consisting of two beta-D-galactosyl-(1->3)-N-acetyl-D-galactosamine disaccharide units linked beta(1->3), to each galactosyl residue of which is linked beta(1->6) a pseudaminyl-(2->6)-D-glucosyl branch. The molecule represents two of the repeat units of the exopolysaccharide of the the Gram negative pathogen Acinetobacter baumannii strain 54149, of which the majority of the repeat units contain the aforementioned linked pseudaminic acid moiety (PMID:29965749).
(2S,4S,5S,6S)-5-acetamido-2-[[(2R,3S,4S,5R,6R)-6-[[(2R,3R,4S,5R,6R)-6-[(2S,3R,4R,5R,6R)-3-acetamido-2-[(2R,3S,4S,5R,6R)-2-[[(2R,3R,4S,5S,6R)-6-[[(2S,4S,5S,6S)-5-acetamido-6-[(1S,2S)-1-acetamido-2-hydroxypropyl]-2-carboxy-4-hydroxyoxan-2-yl]oxymethyl]-3,4,5-trihydroxyoxan-2-yl]oxymethyl]-6-[(3R,4R,5R,6R)-3-acetamido-2,5-dihydroxy-6-(hydroxymethyl)oxan-4-yl]oxy-3,5-dihydroxyoxan-4-yl]oxy-5-hydroxy-6-(hydroxymethyl)oxan-4-yl]oxy-3,4,5-trihydroxyoxan-2-yl]methoxy]-3,4,5-trihydroxyoxan-2-yl]methoxy]-6-[(1S,2S)-1-acetamido-2-hydroxypropyl]-4-hydroxyoxane-2-carboxylic acid