The molecule is a disaccharide comprising a 3-deoxy-alpha-D-manno-oct-2-ulopyranonosonyl unit in (2->4) linkage with D-glycero-alpha-D-talo-oct-2-ulosonic acid; it is found in the core structure of bacterial lipopolysaccharides.
(2R,3S,4S,5S,6R)-4-[(2S,4R,5R,6R)-2-carboxy-6-[(1R)-1,2-dihydroxyethyl]-4,5-dihydroxyoxan-2-yl]oxy-6-[(1R)-1,2-dihydroxyethyl]-2,3,5-trihydroxyoxane-2-carboxylic acid