Structure of condensation products between isonicotinylhydrazine and reducing sugars by 13C nmr spectroscopy

Abstract

The structures of the condensation products of isonicotinylhydrazine (isoniazid) with galactose, glucose, lactose, maltose, glycolaldehyde and glyceraldehyde were investigated by examination of their ¹³C nmr spectra, determined in D₂O and DMSO-d₆ solution. Spectroscopic data and their interpretation are presented. Spectroscopic and chromatographic (hplc) evidence are combined to show that the products formed with the four sugars exist in solution predominantly as l-(1β-pyranosyl)-2-isonicotinylhydrazines, and to a lesser extent as the analogous 1α-pyranosyl anomers. The products formed with glycolaldehyde and glyceraldehyde are normal hydrazones.