TY - JOUR

T1 - Parahydrogen-Induced Polarization Relayed via Proton Exchange

AU - Them, Kolja

AU - Ellermann, Frowin

AU - Pravdivtsev, Andrey N.

AU - Salnikov, Oleg G.

AU - Skovpin, Ivan V.

AU - Koptyug, Igor V.

AU - Herges, Rainer

AU - Hövener, Jan Bernd

N1 - Funding Information: We acknowledge support by the Emmy Noether Program “Metabolic and Molecular MR” (HO 4604/2-2), the research training circle “Materials for Brain” (GRK 2154/1-2019), DFG-RFBR grant (HO 4604/3-1, No 19-53-12013), Cluster of Excellence “Precision Medicine in Inflammation” (PMI 2167), German Federal Ministry of Education and Research (BMBF) within the framework of the e:Med research and funding concept (01ZX1915C). Kiel University and the Medical Faculty are acknowledged for supporting the Molecular Imaging North Competence Center (MOIN CC, MOIN 4604/3). MOIN CC was founded by a grant from the European Regional Development Fund (ERDF) and the Zukunftsprogramm Wirtschaft of Schleswig-Holstein (Project no. 122-09-053). The Russian team thanks the Russian Foundation for Basic Research (Grant 19-53-12013) for financial support. Publisher Copyright: © 2021 The Authors. Published by American Chemical Society.

PY - 2021/9/1

Y1 - 2021/9/1

N2 - The hyperpolarization of nuclear spins is a game-changing technology that enables hitherto inaccessible applications for magnetic resonance in chemistry and biomedicine. Despite significant advances and discoveries in the past, however, the quest to establish efficient and effective hyperpolarization methods continues. Here, we describe a new method that combines the advantages of direct parahydrogenation, high polarization (P), fast reaction, and low cost with the broad applicability of polarization transfer via proton exchange. We identified the system propargyl alcohol + pH2 → allyl alcohol to yield 1H polarization in excess of P ≈ 13% by using only 50% enriched pH2 at a pressure of ≈1 bar. The polarization was then successfully relayed via proton exchange from allyl alcohol to various target molecules. The polarizations of water and alcohols (as target molecules) approached P ≈ 1% even at high molar concentrations of 100 mM. Lactate, glucose, and pyruvic acid were also polarized, but to a lesser extent. Several potential improvements of the methodology are discussed. Thus, the parahydrogen-induced hyperpolarization relayed via proton exchange (PHIP-X) is a promising approach to polarize numerous molecules which participate in proton exchange and support new applications for magnetic resonance.

AB - The hyperpolarization of nuclear spins is a game-changing technology that enables hitherto inaccessible applications for magnetic resonance in chemistry and biomedicine. Despite significant advances and discoveries in the past, however, the quest to establish efficient and effective hyperpolarization methods continues. Here, we describe a new method that combines the advantages of direct parahydrogenation, high polarization (P), fast reaction, and low cost with the broad applicability of polarization transfer via proton exchange. We identified the system propargyl alcohol + pH2 → allyl alcohol to yield 1H polarization in excess of P ≈ 13% by using only 50% enriched pH2 at a pressure of ≈1 bar. The polarization was then successfully relayed via proton exchange from allyl alcohol to various target molecules. The polarizations of water and alcohols (as target molecules) approached P ≈ 1% even at high molar concentrations of 100 mM. Lactate, glucose, and pyruvic acid were also polarized, but to a lesser extent. Several potential improvements of the methodology are discussed. Thus, the parahydrogen-induced hyperpolarization relayed via proton exchange (PHIP-X) is a promising approach to polarize numerous molecules which participate in proton exchange and support new applications for magnetic resonance.

UR - http://www.scopus.com/inward/record.url?scp=85114174069&partnerID=8YFLogxK

U2 - 10.1021/jacs.1c05254

DO - 10.1021/jacs.1c05254

M3 - Article

C2 - 34406748

AN - SCOPUS:85114174069

VL - 143

SP - 13694

EP - 13700

JO - Journal of the American Chemical Society

JF - Journal of the American Chemical Society

SN - 0002-7863

IS - 34

ER -