Modern proton‐detected 1D ¹H–¹⁵N NMR experiments. Application to the measurement of ¹H,¹⁵N coupling constants at natural abundance

Abstract

Non-selective and selective versions of several proton-detected 1D NMR experiments to be applied to 15 N are proposed. Clean, artifact-free 1D spectra are easily obtained by the effective coherence selection by pulsed-field gradients and the attainable sensitivity is maximized using modern pulse schemes. Despite the low sensitivity inherent to 15 N NMR spectroscopy, the successful application of these experiments is demonstrated for resonance assignments and accurate measurement of both one-bond and long-range proton-nitrogen coupling constants on a model tripeptide at natural abundance.

15N NMR Spectroscopy in Structural Analysis: An Update (2001 - 2005)

“…Parella [36] (CH3)2NH 12.2 [30] 1,4-dinitrobenzene 367.9 [36] (CH3)3N 18.6 [30] pyrrole 149-158 [37] CH3NH2*HCl 20.3 [30] imidazole 196-214 b [3][4][5][6][7] piperidine 35.8 [31] pyrazole 301.6, 208.5 [38] N-methylpiperidine 41.4 [31] pyridine 286-328 [3][4][5][6][7] aniline 61.4 [32] N-methylpyridinium ion 203.5 [3][4][5][6][7] N-methylaniline 57.7 [33] azobenzene E-isomer 510.7 [39] N,N-dimethylaniline 49.5 [33] azobenzene Z-isomer 528.2 [39] 4-nitroaniline 80.5 (-NH2) [34] nitrosobenzene 913.7 [40] benzonitrile 260.2 [35] a 15 N chemical shifts referred to liquid ammonia. and Belloc [41] proposed and described non-selective and selective versions of several 1D 1 H- 15 N NMR experiments for this purpose and obtained clean, artifact-free 1D spectra. and Belloc [41] proposed and described non-selective and selective versions of several 1D 1 H- 15 N NMR experiments for this purpose and obtained clean, artifact-free 1D spectra.…”

Exploiting the carboxylate chemical shift to resolve degenerate resonances in spectra of13C-labelled glycosaminoglycans

“…This is effectively a HC 5 C 6 -TOCSY experiment, conceptually similar to heteronuclear experiments described previously. 32 The spectra obtained with either of the pulse schemes in Figs 2b and c (the latter modified to dephase zero-quantum coherences, as described in the Results section) consist of a series of 1 H resonances at each 13 C chemical shift, indicating protons to which magnetisation from a particular H 5 proton was transferred after the HC 5 C 6 section of the sequence. Therefore, unique spin-systems for individual GlcA residues can be separated using a 13 C nucleus.…”

Assignment of oxime and hydrazone configuration using 1H‐15N and 13C‐15N coupling measurements at natural abundance

“… Unfortunately, because of the requirement at the time for isotopically labeled samples, the early promise of this method could not be realized. Advances in spectrometer and probe technology now allow routine measurement of 1 H‐ 15 N coupling to be accomplished using a variety of techniques . Specifically, variants of the HSQMBC pulse sequence have been proven to be especially useful .…”

“…Advances in spectrometer and probe technology now allow routine measurement of 1 H-15 N coupling to be accomplished using a variety of techniques. [9][10][11] Specifically, variants of the HSQMBC pulse sequence have been proven to be especially useful. [12][13][14] In addition, we recently introduced a new pulse sequence for measurement of 13 C-15 N coupling at natural abundance, the HCNMBC experiment.…”