Degradation during the hydrazinolysis of 2-acetamido-1-N-acyl-2-deoxy-β-D-glucopyranosylamines
-
Tang, P. W.,Williams, J. Michael
p. C13 - C15
(2007/10/02)
FURTHER STUDIES OF THE HYDRAZINOLYSIS OF 2-ACETAMIDO-1-N-ACYL-2-DEOXY-β-D-GLUCOPYRANOSYLAMINES
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.
Tang, Ping W.,Williams, J. Michael
p. 89 - 98
(2007/10/02)
MODEL STUDIES PERTAINING TO THE HYDRAZINOLYSIS OF GLYCOPEPTIDES AND GLYCOPROTEINS: HYDRAZINOLYSIS OF THE 1-N-ACETYL AND 1-N-(L-β-ASPARTYL) DERIVATIVES OF 2-ACETAMIDO-2-DEOXY-β-D-GLUCOPYRANOSYLAMINE
The products of hydrazinolysis of the 1-N-acetyl and 1-N-(L-β-aspartyl) derivatives of 2-acetamido-2-deoxy-β-D-glucopyranosylamine could not be converted quantitatively into 2-amino-2-deoxy-D-glucose under mild conditions.Proton and (13)C-n.m.r. measurements indicated that the hydrazone of 2-amino-2-deoxy-D-glucose was a major product of the hydrazinolysis of 2-acetamido-1-N-acetyl-2-deoxy-β-D-glucopyranosylamine.Control experiments showed that acetohydrazide is slowly converted into 4-amino-3,5-dimethyl-1,2,4-triazole under the conditions of hydrazinolysis, and hat 2-amino-2-deoxy-D-glucose reacts slowly with acetohydrazide in dilute acetic acid.The implications of these results in relation to the hydrazinolysis of glycopeptides and glycoproteins are discussed.
Saeed, May S.,Williams, J. Michael
p. 83 - 94
(2007/10/02)
More Articles about upstream products of 18615-50-4