The molecule is an amino disaccharide consisting of N-acetyl-beta-D-galactosamine having a 4-deoxy-alpha-L-threo-hex-4-enopyranuronosyl residue attached at the 3-position. It is an amino disaccharide and a monocarboxylic acid. It is a conjugate acid of a beta-D-4-deoxy-Delta(4)-GlcpA-(1->3)-beta-D-GalpNAc(1-).
(2R,3R,4S)-2-[(2R,3R,4R,5R,6R)-3-acetamido-2,5-dihydroxy-6-(hydroxymethyl)oxan-4-yl]oxy-3,4-dihydroxy-3,4-dihydro-2H-pyran-6-carboxylic acid