Wong Alan, Hung Ivan, Howes Andy P, Anupõld Tiit, Past Jaan, Samoson Ago, Brown Steven P, Smith Mark E, Dupree Ray
Physics Department, University of Warwick, Coventry, UK.
Magn Reson Chem. 2007 Dec;45 Suppl 1:S68-72. doi: 10.1002/mrc.2088.
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.
由于强烈的O-H偶极相互作用，通过¹⁷O双旋转（DOR）核磁共振直接检测羟基氧（O-H）极具挑战性。以甘氨酸·盐酸盐为例表明，羟基位点的氘代克服了这一问题。在[(¹⁷O,²H)甘氨酸·盐酸盐的DOR谱中，观察到羧基氧和羟基氧有两组分离良好的窄共振峰（线宽约80 - 100 Hz）及其旋转边带。通过对DOR旋转边带强度的模拟获得了这些位点的化学位移各向异性。发现羧基氧的化学位移跨度（Ω）远大于羟基氧，Ω值分别为540 ± 15 ppm和210 ± 10 ppm。
