1D and 2D NOESY

One-dimensional NOESY relies on selective inversion or saturation of one peak and observing NOE peak at another position. The reliance on selective pulse reduces the sensitivity of the experiment and limits NOE to one 1H at a time. Among the versions of 1D NOE experiments, the NOE difference experiment (noedif or cyclenoe) relies on perfect cancellation of spectra done with and without 1H saturation, a very demanding quality for any spectrometer, particularly older ones. Temperature stability, vibration, hardware instability from scan to scan all contribute artifacts to the cancellation spectrum. Additionally, through-bond coupling artifacts are not suppressed, and are often shown as dispersive signals in the final spectrum, complicating data analysis. NOEDIF or CYCLENOE is NOT the recommended 1D NOESY experiment unless quantitative NOE (% enhancement) is desired. The recommended, gradient enhanced 1D NOESY experiment (NOT based on difference and cancellation) is similar to the 2D experiment shown below, with gradient pulses and zero-quantum suppression.

Whenever possible, the gradient-based 2D NOESY (~ 30mins) is strongly recommended. 2D NOESY has the advantage of using hard pulses to excite all signals at once, more efficient and sensitive. It is also more reliable in distinguishing real NOE peaks from artifacts because of the automatic crosspeak symmetry present.

2D Gradient Enhanced NOESY

The following figure is the gradient based 2D NOESY pulse sequence with the main parameters displayed (NMR500). This sequence uses Z-gradient to crush zero-quantum (via J-coupling) artifact contribution, often shown as dispersive peaks. This is the best choice of mordern 2D 1H-1H experiments.


Procedure (on NMR600)

Default means the settiong is already in place by default, unless changed by a user.

Default parameters

The default setting (modified from Varian's default values) in our parameter set uses the following for a quick 2D NOESY:

Data Processing

You can use vnmrJ to process the data, but vnmrJ's graphics display for 2D spectrum leaves much to be desired. A separate program is strongly recommended for detailed processing and analysis. Mnova and nmrPipe/nmrDraw are installed on NMR600 and the data processing station.

Example spectrum collected on NMR500

NOESY Spectrum

Expansion of the 1.4ppm to 4.7ppm region

NOESY Expansion

H.Zhou updated April 2012