Signal Amplification By Reversible Exchange (SABRE) can provide strong signal enhancement (SE) to an array of molecules through reversible exchange of parahydrogen (pH₂) derived hydrides and a suitable substrate coordinated to a transition metal. Among the substrates that can be used as a probe for hyperpolarised NMR and MRI, pyruvate has gained much attention. SABRE can hyperpolarise pyruvate in a low cost, fast, and reversible fashion that does not involve technologically demanding equipment. Most SABRE polarization studies have been done using methanol-d₄ as a solvent, which is not suitable for in vivo application. The main goal of this work was to obtain hyperpolarized pyruvate in a solvent other than methanol which may open the door to further purification steps and enable a method to polarize pyruvate in water in future. This work demonstrates hyperpolarization of the [2-¹³C]pyruvate as well as [1-¹³C]pyruvate by SABRE in an acetone/water solvent system at room temperature as an alternative to methanol, which is commonly used. NMR signals are detected using a 1.1 T benchtop NMR spectrometer. In this work we have primarily focused on the study of [2-¹³C]pyruvate and investigated the effect of catalyst concentration, DMSO presence and water vs. acetone solvent concentration on the signal enhancement. The relaxation times for [2-¹³C]-pyruvate solutions are reported in the hope of informing the development of future purification methods.

中文翻译：

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13C SABRE 在丙酮/水混合物中超极化 [2-13C]-丙酮酸


通过可逆交换进行信号放大 （SABRE） 可以通过对氢 （pH₂） 衍生的氢化物和与过渡金属配位的合适衬底的可逆交换，为分子阵列提供强信号增强 （SE）。在可用作超极化 NMR 和 MRI 探针的底物中，丙酮酸受到广泛关注。SABRE 可以以低成本、快速和可逆的方式超极化丙酮酸，而无需使用技术要求高的设备。大多数 SABRE 极化研究是使用甲醇-d₄ 作为溶剂完成的，这不适合体内应用。这项工作的主要目标是在甲醇以外的溶剂中获得超极化丙酮酸，这可能会为进一步的纯化步骤打开大门，并在未来能够实现在水中极化丙酮酸的方法。这项工作证明了 SABRE 在室温下丙酮/水溶剂体系中 [^2-13C] 丙酮酸和 [^1-13C] 丙酮酸的超极化，作为常用甲醇的替代品。使用 1.1 T 台式 NMR 波谱仪检测 NMR 信号。在这项工作中，我们主要关注 [2-13 C] 丙酮酸的研究，并研究了催化剂浓度、DMSO 存在和水与丙酮溶剂浓度对信号增强的影响。报告了 [^2-13C]-丙酮酸溶液的弛豫时间，以期为未来纯化方法的开发提供信息。