Nuclear magnetic resonance spectra of heparin in admixture with dermatan sulfate and other glycosaminoglycans. 2-D spectra of the chondroitin sulfates

Characteristics of the 1H-n.m.r. spectra of heparin admixed with other glycosaminoglycans are described with respect to the identification of the latter as possible contaminants of pharmaceutical heparins. Chemical shift differences are sufficiently large, particularly with the aid of resolution enhancement, to allow for the detection of dermatan sulfate, chondroitin 4- or 6-sulfate, hyaluronic acid, or heparan sulfate as a minor constituent in the presence of heparin. The acetamidomethyl resonance region (delta 1.95-2.15) is especially useful in this context, both for identification and quantitative estimation. Whereas dermatan sulfate is a common contaminant of pharmaceutical heparin preparations, in some instances comprising 10-15 percent of the polymer mixture, the other glycosaminoglycans, by contrast, were not detected in such preparations. Two-dimensional heterocorrelation and homo-correlation n.m.r. experiments have provided 1H- and 13C-chemical shift data that complete or verify (or both) previous information available for heparin, dermatan sulfate, and chondroitin 4- and 6-sulfates (chondroitins A and C).