THE ACTION OF HYPOCHLOROUS ACID ON POLYMERIC COMPONENTS OF CARTILAGE

The action of sodium hypochlorite on N-acetylglucosamine, N-acetylgala ctosamine, chondroitinsulfate and hyaluronic acid was studied by H-1-n uclear magnetic resonance (H-1-NMR) in order to model some aspects of degradation processes caused by neutrophils on carbohydrate polymers o f cartilage in rheumatoid arthritis. N-Acetyl side groups of carbohydr ate monomers and chondroitinsulfate yield a resonance at 2.01-2.04 ppm in proton NMR-spectra. This resonance is observed in hyaluronic acid solutions only after a prolonged incubation to yield shorter polymeric chains. Sodium hypochlorite causes a continuous decrease of the line for N-acetyl groups. Two new resonances appear in the H-1-NMR spectra. An intermediate product, assumed as a chlorinated product of N-acetyl side chains, shows a chemical shift of about 2.35 ppm. This intermedi ate is hydrolyzed to a carbohydrate ring and acetate (1.90 ppm). Sodiu m hypochlorite acts in all systems investigated mainly on N-acetyl gro ups. Only small effects on the carbohydrate ring were found under our experimental conditions.