The determination of 17O NMR parameters of hydroxyl oxygen: a combined deuteration and DOR approach

The direct detection of hydroxyl oxygen (O-H) by (17)O double-rotation (DOR) NMR is very challenging because of the strong O-H dipole interaction. It is shown that deuteration of the hydroxyl site overcomes this using glycine.HCl as an illustration. Two well-separated sets of narrow (linewidth approximately 80-100 Hz) resonances with their spinning-sidebands are observed for the carboxyl and hydroxyl oxygens in the DOR spectrum of (17)O,(2)H]glycine.HCl. The chemical shift anisotropy of these sites is obtained from a simulation of the DOR spinning-sideband intensities. The chemical shift span (Omega) for the carboxyl oxygen is found to be much larger than that of the hydroxyl oxygen, with Omega values of 540 +/- 15 and 210 +/- 10 ppm, respectively.