Unsaturated chondroitin disaccharide hydrolase (EC 3.2.1.180, UGL, unsaturated glucuronyl hydrolase) is an enzyme with systematic name beta-D-4-deoxy-Delta4-GlcAp-(1->3)-beta-D-GalNAc6S hydrolase. This enzyme catalyses the following chemical reactionbeta-D-4-deoxy-Delta4-GlcAp-(1->3)-beta-D-GalNAc6S + H2O 5-dehydro-4-deoxy-D-glucuronate + N-acetyl-beta-D-galactosamine-6-O-sulfate