Radio-Frequency Sweeps at Microtesla Fields for Parahydrogen- Induced Polarization of Biomolecules
Radio-Frequency Sweeps at Microtesla Fields for Parahydrogen- Induced Polarization of Biomolecules
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DOI：
10.1021/acs.jpclett.2c03785
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发表时间：
2023-02-20
影响因子：
5.7
通讯作者：
Knecht, Stephan
中科院分区：
文献类型：
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作者：
Marshall, Alastair;Salhov, Alon;Knecht, Stephan
通过对氢诱导极化(PhIP)增强的13C标记代谢物的磁共振成像能够实时监测体内的过程。我们介绍了一种健壮的，易于实现的技术，通过在微特斯拉磁场中进行绝热射频扫描，将对氢衍生的单重态顺序转化为13C磁化。我们通过实验证明了这种技术对几个分子的适用性，包括一些与代谢成像相关的分子，在这些分子中，我们显示了可实现的极化的显著改善，在某些情况下达到了60%以上的核自旋极化。此外，我们还引入了一种位置选择性的氢化方案，其中，在丙酮酸酯的耦合网络中加入了氚，以提高极化转移的效率。这些改进是由于传输协议避免了强耦合四极核引起的驰豫。
Magnetic resonance imaging of 13C-labeled metabolites enhanced by parahydrogen-induced polarization (PHIP) enables real-time monitoring of processes within the body. We introduce a robust, easily implementable technique for transferring parahydrogen-derived singlet order into 13C magnetization using adiabatic radio frequency sweeps at microtesla fields. We experimentally demonstrate the applicability of this technique to several molecules, including some molecules relevant for metabolic imaging, where we show significant improvements in the achievable polarization, in some cases reaching above 60% nuclear spin polarization. Furthermore, we introduce a site-selective deuteration scheme, where deuterium is included in the coupling network of a pyruvate ester to enhance the efficiency of the polarization transfer. These improvements are enabled by the fact that the transfer protocol avoids relaxation induced by strongly coupled quadrupolar nuclei.