AB05831, also known as 2-Acetamido-1,2-dideoxynojirimycin, is a highly potent and specific inhibitor of beta-hexosaminidase. N-Acetyl-3-hexosaminidase (HEX) is a member of lysosomal hydrolases, which catalyzes hydrolysis of terminal, non-reducing N-acetyl-|3-D-glucosamine (GlcNAc) andN-acetyl-(3-D-galactosamine (GalNAc) residues in glycoproteins, gan-gliosides, and glycosaminoglycans (GAGs). HEX, released by chondrocytes into the extracellular compartment, promotes cartilage matrix degradation. Osteoarthritis patients have increased HEX activity in synovial fluid.