FURTHER STUDIES OF THE HYDRAZINOLYSIS OF 2-ACETAMIDO-1-N-ACYL-2-DEOXY-β-D-GLUCOPYRANOSYLAMINES

Article abstract of DOI:10.1016/0008-6215(83)84008-7

1-Deoxy-D-fructose hydrazone is shown to be the major product of the hydrazinolysis of 2-amino-2-deoxy-D-glucose hydrazone and can be detected as a minor product of the hydrazinolysis of 2-acetamido-1-N-acetyl-2-deoxy-β-D-glucopyranosylamine.The hydrazinolysis conditions (100 deg C, 30 h, no catalyst) of Bayard and Montreuil are inefficient for the cleavage of the amide groups of 2-acetamido-1-N-acetyl-2-deoxy-β-D-glucopyranosylamine, unchanged starting-material and 1-N-acetyl-2-amino-2-deoxy-β-D-glucopyranosylamine accounting for 70percent of the product mixture.Under the same conditions, the hydrazinolysis of 2-acetamido-1-N-(L-β-aspartyl)-2-deoxy-β-D-glucopyranosylamine gave 2-amino-2-deoxy-D-glucose hydrazone as major product together with ca. 14percent of 1-deoxy-D-fructose hydrazone.Participation by the carboxyl group of the asparagine residue is invoked to account for the greater reactivity of the asparagine derivative.The hydrazinium sulphate-catalysed hydrazinolysis gave a higher yield (44percent) of 1-deoxy-D-fructose hydrazone when applied to the asparagine derivative.The implications of these results in relation to the hydrazinolysis of glycopeptides and glycoproteins are discussed.