Chondroitin sulfate (CS) is classified as a member of the glycosaminoglycans (GAGs), also known as mucopolysaccharides, which are carbohydrate side chains that are essential components of proteoglycans. All glycosaminoglycans consist of 1,4-glycosidically linked disaccharide units. In the case of chondroitins, sulfuric acid is regularly attached to oxygen or nitrogen atoms, so that they usually react strongly acidic. Chondroitin sulfates A and C are composed of glucuronic acid and N-acetyl-D-galactosamine. Chondroitin sulfate B has a similar structure. It is known as dermatan sulfate or beta-heparin from L-iduronic acid and NAG-4-sulfate.
On the one hand, chondroitin sulfate enters the body through food. It is found in meat and marine animals, especially in mussels and oysters. On the other hand, the glycosaminoglycan can be formed in the body itself. Endogenous synthesis requires glucosamine sulfate, the preferred substrate for glycosaminoglycan biosynthesis. Chondroitin sulfates, as animal proteoglycans, are largely incorporated into cartilage tissues and thus represent the main intercellular components of connective tissue, cartilage and bone. However, they can also be found in skin and body mucus.
Technically, chondroitin sulfates used to be obtained from shark cartilage, and later also from bovine and porcine tracheids, respectively.
