Investigation of the experimental limits of small-sample heteronuclear 2D NMR.

Practical experimental performance limits for an ensemble of heteronuclear 2D NMR experiments using a state-of-the-art 600 MHz 1.7 mm Bruker TCI Micro CryoProbe are reported. In the specific case of multiplicity-edited GHSQC, it was possible to acquire data on a 540 ng sample of strychnine (1; ∼1.6 nmol), prepared by serial dilution, which was used as a model compound. The experiments discussed also included GCOSY, (13)C reference spectra, (1)H-(13)C GHMBC, IDR-GHSQC-TOCSY, 1,1-ADEQUATE, and (1)H-(15)N GHMBC.