Microanalysis of glycosaminoglycan-derived disaccharides labeled with the fluorophore 2-aminoacridone by capillary electrophoresis and high-performance liquid chromatography.

A series of disaccharides derived from chondroitin sulfate and heparin/heparan sulfate were derivatized at their reducing ends with the fluorophore 2-aminoacridone. The resulting labeled compounds derived from chondroitin sulfate or heparin/heparan sulfate were well separated and could be quantified by capillary electrophoresis and HPLC with a fluorescence detector. This method was successfully applied to the analysis of the disaccharide composition of sulfated tetra- and hexasaccharides derived from chondroitin sulfate and heparin/heparan sulfate. Remarkably, the saturated and the corresponding unsaturated chondrodisaccharides, the structures of which differ only in their nonreducing terminal uronic acid residues, were also well separated from each other by capillary electrophoresis. This facilitated disaccharide composition analysis of saturated chondrooligosaccharides prepared by testicular hyaluronidase digestion as well as unsaturated chondro- and heparin/heparan sulfate-oligosaccharides prepared by digestion with chondroitinases and heparitinases. The developed method employing the derivatization by 2-aminoacridone in conjunction with capillary electrophoresis or HPLC with a fluorescence detector allows a simple, sensitive, and quantitative disaccharide composition analysis of the glycosaminoglycan-derived oligosaccharides.