Cyclenoe is a traditional, steady-state NOESY experiment implemented by Varian. The experiment uses on- and off-resonance saturation to give a difference spectrum where NOE peaks are revealed and phased positive and the saturated peak phased negative. The selective saturation can be optionally done with a frequency cycling scheme where the saturation frequency shifts between multiplet peaks. The %NOE is calculated as the integral ratio of the NOE peak over that of the saturation peak. Note that this sequence is not the best sequence to use for qualitative estimate of NOEs in structural and conformational analysis due to its complex setup procedure and artifacts in the spectrum. It is the sequence to use only when traditional quantitative %NOE is needed.

Cyclenoe is one of the trickiest experiments to set up in order to get a clean spectrum due to a number of factors, including hardware stability and parameter settings. Besides the spectrometer and probe stability the recycle delay (d1) and saturation time (sattime) settings may have a big impact on the cleanness of the difference spectrum and the accuracy of the %NOE measurement. Therefore, measuring T1 values for cyclenoe is an important requirement.

The following is a procedure for setting up a cyclenoe experiment, using a test run with a strychnine sample as an example.


In the following, go to Process->Text Output to see text/parameter display. To list the experiment library, type explib. To create a new experiment, type cexp(n) where n is an experiment that does not exist. All parameters will be copied over from the current experiment to the new one. Type jexp(n) to join exp #n.

Step 1:

Step 2: Collect 1H spectrum & set spectral window

Step 3: Estimate Longest T1 (Optional, but highly recommended for data quality)

In order to choose the right duration of d1 and sattime, T1 values of your compound should be measured. Failure to do so compromises the accuracy of the %NOE measurement and may introduce artifacts in the spectrum.


d2 (relaxation delay) is set to 11 elements varying from 0 to 32 seconds appearing from bottom to top in the stack plot (see text field in figure below for array values). On the far right is the TMS 0ppm signal. The longest T1 in strychnine appears for the peak at ~ 8.1ppm.

T1 array

The index of the null crossing point for the 8.1ppm peak is #7 from the bottom, corresponding to a d2 of 2 sec. The T1 value of this 1H is:

Step 4: Find on- and off- resonance saturation frequencies

Step 5: Set up CYCLENOE

Do CYCLENOE under another experiment, here exp3. To create exp3 if it doesn't exist, enter cexp(3). To go to (or join) exp3, enter jexp(3). To find out how long the exp takes, enter time.

What to do with single broad peak?

The choice is (1) to use a single, centered radiation frequency and a higher power (satpwr), or (2) to divide the peak into frequency bins (as in a multiplet peak) and use frequency cycling within the bins at minimum power (satpwr=-16). The 2nd choice might be better (but it also depends on other factors) because at the lowest power the selectivity is better and the saturation is more uniform within the broad peak. To use the 2nd method, in Step 4:


Sample: Strychnine 25mg/mL in CDCL3

Date: October 17, 2010 on NMR500

Experiment time: 14 mins


The following parameters are used (Default values after setexp command, unless changed by users):

1H spectrum

strychnine 1H spectrum

CYCLENOE with 1H saturation set to 5.9ppm

cyclenoe strychnine

scaled to fit window

cyclenoe strychnine

H. Zhou updated June 2017