Analysis of heparin and 6DS-heparin. Samples of heparin and 6DS-heparin were analyzed by 13C-NMR (a and b) and nitrous acid degradation to disaccharides (c and d) (see Methods). (a and b) The positions of peaks 1 and 2 correspond to C6 of 6-O-sulfated and unsubstituted glucosamine units, respectively. (c and d) Disaccharides generated by nitrous acid deamination of heparin and 6DS-heparin, respectively. 1, aManR (anhydromannitol), GlcA-aManR, and IdoA-aManR; 2, IdoA-(2OSO3)-aManR; 3, GlcA(2OSO3)-aManR and GlcA-aManR(6OSO3); 4, IdoA-aManR(6OSO3); 5, GlcA-aManR(3OSO3)(6OSO3); 6, IdoA(2OSO3)-aManR(6OSO3); 7, GlcA(2OSO3)-aManR(6OSO3).