¹H‐NMR analysis of the sugar structures of glycoproteins as their pyridylamino derivatives

The 1H-NMR spectra of a series of pyridylamino (PA-) derivatives of oligosaccharides were obtained and compared with those of the corresponding asparagine-linked sugar chains in order to elucidate the effect of the PA-group on the chemical shifts of structural-reporter signals. The effects were found to be localized within the two residues from the end group. Thus, the data for asparagine-linked chains in the literature are applicable to PA-derivatives, so the combination of pyridylamination and NMR measurements greatly reduces the time required for structure analysis of sugar chains of glycoproteins, because the isolation and purification of the chains as PA-derivatives are easy and efficient.