H-1 nuclear magnetic resonance spectroscopic analysis for determination ofglucuronic and iduronic acids in dermatan sulfate, heparin, and heparan sulfate

H-1 NMR spectroscopy has been established for the determination of uronate residues in glycosaminoglycans (GAGs) such as dermatan sulfate (DS), hepari n (HP), and heparan sulfate (HS). Because of variation in the sulfonation p ositions in DS, HP, or HS, interpretation of spectra is difficult. Solvolys is was applied to remove O-sulfo groups from these GAG chains in dimethyl s ulfoxide containing 10% methanol at 80 degreesC for 5 h. In the cases of HP and HS, N-sulfo groups on glucosamine residues were also removed under the same conditions. The resulting unsubstituted amino groups in HP and HS cha ins were re-N-acetylated using acetic anhydride to obtain homogeneous core structure with the exception of the variation of uronate residues. The cont ents of glucuronate and iduronate residues in the chemically modified DS, H -P, and HS samples were analyzed by 600-MHz H-1 NMR spectroscopy. These met hods were applied to compositional analysis of uronate residues in GAGs iso lated from various sources. (C) 2001 Academic Press.