Mild tagging procedures for the structural analysis of glycans

The reductive oxyamination of model glycan structures has been investigated as a mild, alternative tagging procedure to reductive amination using O-(4 -nitrobenzyl)-hydroxylamine. Grime formation was quantitative, but the redu ction step did not always go to completion. Novel O- and N-substituted 7-hy droxycoumaryl- and 3-methoxybenzylhydroxylamines were synthesized and shown to couple quantitatively with model saccharides by oxime formation and red uctive hydroxyamination, respectively, under very mild, aqueous conditions. The fluorescent derivatives produced show good chromatographic and mass sp ectrometric properties. Both procedures are suitable for the labeling of ca rbohydrates and oligosaccharide fragments from glycosaminoglycan structures , such as heparin and heparan sulfate. (C) 2001 Elsevier Science Ltd. All r ights reserved.