Fig. 1. Disaccharide structure of hyaluronan, chondroitin-6-sulfate and heparin. Hyaluronan is composed of repeating disaccharide units containing J)..glucuronate and N-acetylglucosamine. Chondroitin-6-sulfate consists of J)..glucuronate and N-acetylglucosam1ne-6sulfate and heparin ofJ)..glucuronate-2-sulfate and N-sulfo-J)..glucosamine-6-sui.fate. Unlike other glycosaminoglycans which poss,ess 0rand f}-linkages, hyaluronan and chondroitin-6-sulfatehave exclusively f}-linkagcs, thus endowing them with more rcsistance to degradation.