HWB-NMR, Institute of Cancer Studies, The University of Birmingham, Edgbaston, Birmingham, UK B15 2TT.
Phys Chem Chem Phys. 2010 Jun 14;12(22):5868-71. doi: 10.1039/c002700f. Epub 2010 May 10.
Dynamic nuclear polarization (DNP) has become an attractive technique to boost the sensitivity of NMR experiments. In the case of ex situ polarizations two-dimensional (2D) spectra are limited by the short lifetime of the polarization after dissolution and sample transfer to a high field NMR magnet. This limitation can be overcome by various approaches. Here we show how the use of (13)C-labelled acetyl tags can help to obtain 2D-HMQC spectra for many small molecules, owing to a nuclear Overhauser enhancement between (13)C spins originating from the long-lived carbonyl carbon, which extends the lifetimes of other (13)C spins with shorter longitudinal relaxation times. We also show an alternative approach of using an optimized polarization matrix.
动态核极化 (DNP) 已成为提高 NMR 实验灵敏度的一种有吸引力的技术。在体外极化的情况下，二维（2D）谱受到极化在溶解后和转移到高场 NMR 磁体后的短寿命的限制。可以通过各种方法克服这种限制。在这里，我们展示了如何使用（13）C 标记的乙酰基标签来获得许多小分子的 2D-HMQC 谱，这是由于源自长寿命羰基碳的（13）C 自旋之间的核 Overhauser 增强，从而延长了其他（13）C 自旋的寿命具有较短的纵向弛豫时间。我们还展示了使用优化的极化矩阵的另一种方法。
