The analysis of pyridylamino-dextran sulfate oligomers by high-performance liquid chromatography and a novel detection system for sulfated polysaccharides

Dextran sulfate sodium (DSS) is a strong negatively charged heparin-like polysaccharide and has anti-immunodeficiency virus, anti-carcinogenesis, or occasionally tumor-promotion effects. The biological metabolism of DSS, however, remains unclear. In a previous study, we reported a novel method for the separation and quantification of DSS, using fluorometric labeling with 2-aminopyridine and a combination of size-exclusion and reverse phase high-performance liquid chromatography. In the present study, we have applied this method for analyses of in vitro chemical or enzymatic depolymerization of pyridylamino-DSS (PA-DSS). PA-DSS was depolymerized by specific enzymes such as alpha-amylase and alpha-glycosidase, but not by dextranase or heparinase. Unknown enzymes derived from cultured intestinal cells also strongly depolymerized PA-DSS as did alkaline substances. On the other hand, we have established a novel detection system using a post-column reaction. This method utilizes the spectrophotometrically metachromatic reaction of toluidine blue solution with DSS. This novel detection system may be specific and may potentially provide useful information in the analyses of sulfated polysaccharides, which are present in environmental and biological materials.