Of chondroitinsulfuric acid

According to Wolfrom, Madison and Cron,40 the repeating unit of chondroitinsulfuric acid is a disaccharide of D-glucuronic acid and chondrosamine, in which the chondrosamine unit is linked with Cl and C4 of D-glucuronic acid. However, Bray, Gregory and Stacey41 conclude... 

The Uronic Acid Component of Chondroitinsulfuric Acid, M. L. Wolfrom and W. Brock Neely, /. Amer. Chem. Soc., 75, 2778 (1953). 

In animal tissue, D-glucuronic acid has only been shown to occur as a component of hyaluronic acid, chondroitinsulfuric acid, mucoitinsulfuric acid, heparin, and the conjugates of D-glucuronic acid. In contrast to the mucopolysaccharides, the conjugates of D-glucuronic acid are relatively simple compounds. 

Stacey has written an excellent review on the subject of mucopolysaccharides, which he classified on the basis of their containing both hexosamine and hexuronic acid residues, one or the other of these sugar derivatives, or neither. Hyaluronic acid, chondroitinsulfuric acid. Type I pneumococcal polysaccharides, and heparin are members of the first class. Types II, III, and VIII pneumococcal polysaccharides are examples containing hexuronic acid but no hexosamine. Chi tin and Types IV and XIV pneiuno-coccal polysaccharides contain hexosamine but no hexuronic acid and bacterial dextrans, mold polysaccharides, and levans contain neither hexosamine nor hexuronic acid. 

The spontaneous, /8-eliminative depolymerization is a rapid procedure that can be measured either by the change in viscosity or by the increase in the u.v. absorption. It was furthermore observed that the ability for /3-eliminative depolymerization of the pectic material depends on the number of esterified D-galactopyranuronate residues in the glycuronan chain. This depolymerization proved to be an endocyclic, enolacetal-forming j8-elimination, similar to the enzyme-catalyzed process for hyaluronic acid, chondroitinsulfuric acids, and heparin,... 

In addition to being present in low concentrations in detoxication products in the urine and blood, glucuronic acid is present in mucopolysaccharides such as hyaluronic acid, heparin, chondroitinsulfuric acid and mucoitinsulfuric acid. Preparation of glucuronic acid from mucopolysaccharides is difficult certain plant gums such as gum arabic form a better, although still unsatisfactory, source. 

Polysaccharides composed of the same monomers as chondroitinsulfuric acid and apparently closely related to it have been isolated from umbilical cord (271) and from pig skin (268). The polysaccharides from both these sources, however, unlike the chondroitinsulfuric acid of cartilage, showed resistance to hydrolysis with a preparation of testicular hyaluronidase, and also had different optical rotations. 

Heparin resembles chondroitinsulfuric acid and mucoitinsulfuric acid in that it is composed of glucuronic acid (449), a hexosamine (in this case glucosamine), and contains sulfate groups. Most investigators also report the presence of acetyl groups as in the case of chondroitin- and mucoitinsulfuric acids, but Wolfrom s analyses (452) of heparin did not reveal their presence. As with these related compounds, the structure of heparin has... 

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