ASSIGNMENT OF C-13 CPMAS NMR-SPECTRA OF CRYSTALLINE METHYL BETA-D-GLUCOPYRANOSIDE AND SUCROSE USING DEUTERIUM LABELING AND INTERRUPTED PROTON DECOUPLING

The solid state13C cross polarization magic angle spinning (CPMAS) NMR spectra of partially deuterated samples of methyl β-D-glucopyranoside (1) and sucrose (2) were assigned using the spectral editing technique of interrupted proton decoupling (IPD). With the exception of the deuterium substituted CH2OH each carbon resonance area of the IPD spectra, (after allowing for differences in magnetization) corresponded closely with the established level of deuteration at each site. A direct relationship between the level of deuteration and observed13C resonance intensity facilitated a number of13C CPMAS isotropic shift assignments without resorting to expensive and complex13C labelling. In general, the procedure is excellent for assigning deuterium exchangeable methine carbon resonances in solid state carbohydrate spectra, however, the methodology is problematic when applied to the identification of CH2 and CH3resonances, which are not readily recognizable from the characteristic position of their chemical shifts. © 1990, Taylor & Francis Group, LLC. All rights reserved.