Real-time monitoring of chemical transformations by ultrafast 2D NMR spectroscopy
Real-time monitoring of chemical transformations by ultrafast 2D NMR spectroscopy
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DOI：
10.1021/ja0564158
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发表时间：
2006-01-25
影响因子：
15
通讯作者：
Frydman, L
中科院分区：
文献类型：
--
作者：
Gal, M;Mishkovsky, M;Frydman, L
最近提出了一种能够在一次扫描中获得2D核磁共振(核磁共振)谱的方法。这种“超高速”数据采集格式开辟了一个很有前途的应用领域，涉及在化学变化发生时实时监测它们。本文用两个例子说明了其中的一些潜力：(I)遵循质子化蛋白质在D2O中溶解时发生的H/D交换过程，以及(Ii)实时原位跟踪瞬变的Meisenheimer络合物，该络合物是在核磁共振观察管内快速混合两种有机反应物形成的。第一次测量包括获得一系列由约4 S分隔的2D H-1-N-15HSQC核磁共振谱；在最初的死时间之后，这使我们能够在位置分辨的水平上监测泛素中氢交换的动力学。第二种方法使我们能够观察到，在反应触发后约2 S内，通过一系列2D TOCSY模式的变化，热力学和动力学控制之间的竞争。在此介绍的实时动态实验因此增加了一个基于2D核磁共振的快速表征技术家族；简要讨论了它们的潜力和局限性。
An approach enabling the acquisition of 2D nuclear magnetic resonance (NMR) spectra within a single scan has been recently proposed. A promising application opened up by this "ultrafast" data acquisition format concerns the monitoring of chemical transformations as they happen, in real time. The present paper illustrates some of this potential with two examples: (i) following an H/D exchange process that occurs upon dissolving a protonated protein in D2O, and (ii) real-time in situ tracking of a transient Meisenheimer complex that forms upon rapidly mixing two organic reactants inside the NMR observation tube. The first of these measurements involved acquiring a train of 2D H-1-N-15 HSQC NMR spectra separated by ca. 4 s; following an initial dead time, this allowed us to monitor the kinetics of hydrogen exchange in ubiquitin at a site-resolved level. The second approach enabled us to observe, within ca. 2 s after the triggering of the reaction, a competition between thermodynamic and kinetic controls via changes in a series of 2D TOCSY patterns. The real-time dynamic experiments hereby introduced thus add to an increasing family of fast characterization techniques based on 2D NMR; their potential and limitations are briefly discussed.