A natural high-viscosity mucopolysaccharide with alternating beta (1-3) glucuronide and beta (1-4) glucosaminidic bonds. It is found in the umbilical cord, in vitreous humor, in synovial fluid, in pathologic joints, in group A and C hemolytic streptococci, and in Wharton's jelly. A high urinary level is found in progeria.

Pharmacological actions: Adjuvants, Immunologic