NMR Analysis on Acetamide and N-Methyl Groups of Mucopolysaccharides

Abstract

N-Acetate-methyl signals were examined in the NMR spectra of a series of mucopolysaccharides and some glycopeptides in reference with those of the component monosaccharides involving axial or equatorial acetamide group. The signals showed no significant change on the chemical shifts and shaps in 8M urea, 1 N NaOH, 1 N HCl and D₂O. The signals appeared in δ 2.00 to 2.06 ppm which fall in equatorial region. These results indicate that hexosamine moieties in these polymers keep the C l conformation in solutions. A deshielding effect of N-methyl group on the N-acetate-methyl signals was evident with N-methylated mucopolysaccharides.