Reconstruction of full high-resolution HSQC using signal split in aliased spectra

Resolution enhancement is a long-sought goal in NMR spectroscopy. In conventional multidimensional NMR experiments, such as the ¹H-¹³C HSQC, the resolution in the indirect dimensions is typically 10 to 100 times lower as in 1D spectra because it is limited by the experimental time. Reducing the spectral window can significantly increase the resolution, but at the cost of ambiguities in frequencies as a result of spectral aliasing. Fortunately, this information is not completely lost, and can be retrieved using methods in which chemical shifts are encoded in the aliased spectra and decoded after processing to reconstruct high-resolution ¹H-¹³C HSQC spectrum with full spectral width and a resolution similar to that of 1D spectra. We applied a new reconstruction method called RHUMBA to spectra obtained using the DENA-HSQC and the new AMNA-HSQC experiments. The reconstructed spectra significantly facilitates both manual and automated spectral analysis and structure elucidation based on heteronuclear 2D experiments. The resolution is enhancement by two orders of magnitudes without the usual complications due to spectral aliasing.