Preparation and properties of fluorescent glycosamino-glycuronans labeled with 5-aminofluorescein

The uronic acid residues of all known glycosaminoglycuronans reacted with 5-aminofluorescein to yield fluorescent glycosaminoglycuronan derivatives, which showed fluorescence characteristics identical to those of fluorescein or 5-acetamidofluorescein. The fluorescent products could be purified by chromatography on Octyl-Sepharose; three preparations of labeled chondroitin 6-sulfate having different degrees of substitution, and a labeled heparin were obtained. Fluorescent hyaluronic acid containing labeled and unlabeled molecules was digested with testicular hyaluronidase to give fluorescent oligosaccharides. Fluorescent chondroitin 6-sulfate was treated with chondroitinase AC to give a nonfluorescent disaccharide and minor proportion of fluorescent octasaccharide. Fluorescent heparin retained its anticoagulant activity, which was similar to that of the starting heparin; its half-life in circulating rabbit blood was 36 min (by fluorometry) and 45 min (by clotting-time assay).