by Keyword: Sabre
Schmidt, AB, Eills, J, Dagys, L, Gierse, M, Bock, M, Lucas, S, Bock, M, Schwartz, I, Zaitsev, M, Chekmenev, EY, Knecht, S, (2023). Over 20% Carbon-13 Polarization of Perdeuterated Pyruvate Using Reversible Exchange with Parahydrogen and Spin-Lock Induced Crossing at 50 μT Journal Of Physical Chemistry Letters 14, 5305-5309 
Carbon-13 hyperpolarized pyruvate is about to become the next-generation contrast agent for molecular magnetic resonance imaging of cancer and other diseases. Here, efficient and rapid pyruvate hyperpolarization is achieved via signal amplification by reversible exchange (SABRE) with parahydrogen through synergistic use of substrate deuteration, alternating, and static microtesla magnetic fields. Up to 22 and 6% long-lasting 13C polarization (T1 = 3.7 ± 0.25 and 1.7 ± 0.1 min) is demonstrated for the C1 and C2 nuclear sites, respectively. The remarkable polarization levels become possible as a result of favorable relaxation dynamics at the microtesla fields. The ultralong polarization lifetimes will be conducive to yielding high polarization after purification, quality assurance, and injection of the hyperpolarized molecular imaging probes. These results pave the way to future in vivo translation of carbon-13 hyperpolarized molecular imaging probes prepared by this approach.
JTD Keywords: hydrogen, nmr, Sabre
Van Dyke, ET, Eills, J, Picazo-Frutos, R, Sheberstov, KF, Hu, YA, Budker, D, Barskiy, DA, (2022). Relayed hyperpolarization for zero-field nuclear magnetic resonance Science Advances 8, eabp9242
Zero- to ultralow-field nuclear magnetic resonance (ZULF NMR) is a rapidly developing form of spectroscopy that provides rich spectroscopic information in the absence of large magnetic fields. However, signal acquisition still requires a mechanism for generating a bulk magnetic moment for detection, and the currently used methods only apply to a limited pool of chemicals or come at prohibitively high cost. We demonstrate that the parahydrogen-based SABRE (signal amplification by reversible exchange)-Relay method can be used as a more general means of generating hyperpolarized analytes for ZULF NMR by observing zero-field J-spectra of [C-13]-methanol, [1-C-13]-ethanol, and [2(-13) C]-ethanol in both C-13-isotopically enriched and natural abundance samples. We explore the magnetic field dependence of the SABRE-Relay efficiency and show the existence of a second maximum at 19.0 +/- 0.3 mT. Despite presence of water, SABRE-Relay is used to hyperpolarize ethanol extracted from a store-bought sample of vodka (%P-H similar to 0.1%).
JTD Keywords: Nmr, Para-hydrogen, Sabre, Spectroscopy
