Exploiting the phase of NMR signals to carry useful information. Application to the measurement of chemical shifts in aliased 2D spectra

Karla Ramírez-Gualito; Damien Jeannerat

doi:10.1002/mrc.4301

Exploiting the phase of NMR signals to carry useful information. Application to the measurement of chemical shifts in aliased 2D spectra

Magn Reson Chem. 2015 Nov;53(11):901-7. doi: 10.1002/mrc.4301. Epub 2015 Aug 20.

Authors

Karla Ramírez-Gualito^{1

2}, Damien Jeannerat²

Affiliations

¹ Centro de Nanociencias y Micro y Nanotecnología, Instituto Politécnico Nacional, México D. F., 07738, Mexico.
² Department of Organic Chemistry, University of Geneva, 1211, Geneva 4, Switzerland.

PMID: 26288958
DOI: 10.1002/mrc.4301

Abstract

Taking advantage of the phase of nuclear magnetic resonance (NMR) signals to encode NMR information is not easy because of their low precision and their sensitivity to nearby signals. We nevertheless demonstrated that the phase in indirect dimension of (1) H-(13) C heteronuclear single quantum coherence (HSQC) signals could provide carbon chemical shifts at low, but sufficient precision to resolve the ambiguities of the chemical shifts in aliased spectra. This approach, we called phase-encoding of the aliasing order Na (PHANA), only requires inserting a constant delay during the t1 evolution time to obtain spectra where signals with mixed phases can be decoded at the processing to reconstruct full spectra with a 15-fold increase in resolution.

Keywords: 13C; 1H; HSQC; NMR; PHANA; cyclosporine A; fast method; phase coding of chemical shifts; spectral aliasing.