Fast access to residual dipolar couplings by single-scan 2D NMR in oriented media.

Residual dipolar couplings (RDCs) have revolutionized the structure determination of biomolecular and organic compounds. So far, their measurement has been rather time-consuming, but one might imagine that RDCs can one day also be useful in the investigation of compounds with limited stability or short lifetimes. For such applications, it is indispensable to shorten the experiment time. In this communication, we show the first measurement of RDCs from single-scan two-dimensional NMR. An ultrafast HSQC NMR pulse sequence is presented, which includes several of the recent improvements brought to ultrafast NMR in terms of sensitivity, resolution, and spectral width. Ultrafast spectra are obtained in as little time as 60 s on an organic compound at natural abundance, namely (+)-isopinocampheol. When extracting the RDCs from these ultrafast data, a good agreement with those extracted from conventional spectra (obtained in a much longer time) is observed. These results point out the efficiency of the ultrafast approach, particularly when considering the total experiment duration.