A polymer of acetylglycosamine, C8H15NO6, and glucuronic acid occurring as alternate units with a high molecular weight. Found in vitreous humor (of the eye), synovial fluid, pathologic joints, group A and C hemolytic streptococci, and skin. It appears to bind water in the interstitial spaces, forming a gel-like substance which holds the cells together. Its solutions are highly viscous. The polymeric structure is broken down by the enzyme hyaluronidase.See “Actimoist” [Active].