The molecule is a Delta(4)-beta-D-GlcpA-(1->3)-D-GalpNAc4S in which the the carbon bearing the anomeric hydroxy group has beta- configuration. It derives from a 4,5-dehydro-D-glucuronic acid and a N-acetyl-beta-D-galactosamine 6-sulfate.
(2R,3R,4R)-2-[(2R,3R,4R,5R,6R)-3-acetamido-2-hydroxy-6-(hydroxymethyl)-5-sulfooxyoxan-4-yl]oxy-3,4,5-trihydroxy-3,4-dihydro-2H-pyran-6-carboxylic acid