TY - JOUR

T1 - Parahydrogen-Induced Polarization of Diethyl Ether Anesthetic

AU - Ariyasingha, Nuwandi M.

AU - Joalland, Baptiste

AU - Younes, Hassan R.

AU - Salnikov, Oleg G.

AU - Chukanov, Nikita V.

AU - Kovtunov, Kirill V.

AU - Kovtunova, Larisa M.

AU - Bukhtiyarov, Valerii I.

AU - Koptyug, Igor V.

AU - Gelovani, Juri G.

AU - Chekmenev, Eduard Y.

N1 - Funding Information: This work was supported by the National Science Foundation under grant CHE-1904780 and by DOD CDMRP under grant W81XWH-15-1-0271. The Russian team thanks the Russian Foundation for Basic Research (Grants 17-54-33037, 19-53-12013, 19-33-60045) and the Russian Ministry of Science and Higher Education (Grant AAAA-A16-116121510087-5). V.I.B., I.V.K. and L.M.K. thank the Russian Science Foundation (Grant 19-13-00172) for the support of hydrogenation with parahydrogen. © 2020 Wiley-VCH GmbH. Copyright: Copyright 2020 Elsevier B.V., All rights reserved.

PY - 2020/10/27

Y1 - 2020/10/27

N2 - The growing interest in magnetic resonance imaging (MRI) for assessing regional lung function relies on the use of nuclear spin hyperpolarized gas as a contrast agent. The long gas-phase lifetimes of hyperpolarized 129Xe make this inhalable contrast agent acceptable for clinical research today despite limitations such as high cost, low throughput of production and challenges of 129Xe imaging on clinical MRI scanners, which are normally equipped with proton detection only. We report on low-cost and high-throughput preparation of proton-hyperpolarized diethyl ether, which can be potentially employed for pulmonary imaging with a nontoxic, simple, and sensitive overall strategy using proton detection commonly available on all clinical MRI scanners. Diethyl ether is hyperpolarized by pairwise parahydrogen addition to vinyl ethyl ether and characterized by 1H NMR spectroscopy. Proton polarization levels exceeding 8 % are achieved at near complete chemical conversion within seconds, causing the activation of radio amplification by stimulated emission radiation (RASER) throughout detection. Although gas-phase T1 relaxation of hyperpolarized diethyl ether (at partial pressure of 0.5 bar) is very efficient, with T1 of ca. 1.2 second, we demonstrate that, at low magnetic fields, the use of long-lived singlet states created via pairwise parahydrogen addition extends the relaxation decay by approximately threefold, paving the way to bioimaging applications and beyond.

AB - The growing interest in magnetic resonance imaging (MRI) for assessing regional lung function relies on the use of nuclear spin hyperpolarized gas as a contrast agent. The long gas-phase lifetimes of hyperpolarized 129Xe make this inhalable contrast agent acceptable for clinical research today despite limitations such as high cost, low throughput of production and challenges of 129Xe imaging on clinical MRI scanners, which are normally equipped with proton detection only. We report on low-cost and high-throughput preparation of proton-hyperpolarized diethyl ether, which can be potentially employed for pulmonary imaging with a nontoxic, simple, and sensitive overall strategy using proton detection commonly available on all clinical MRI scanners. Diethyl ether is hyperpolarized by pairwise parahydrogen addition to vinyl ethyl ether and characterized by 1H NMR spectroscopy. Proton polarization levels exceeding 8 % are achieved at near complete chemical conversion within seconds, causing the activation of radio amplification by stimulated emission radiation (RASER) throughout detection. Although gas-phase T1 relaxation of hyperpolarized diethyl ether (at partial pressure of 0.5 bar) is very efficient, with T1 of ca. 1.2 second, we demonstrate that, at low magnetic fields, the use of long-lived singlet states created via pairwise parahydrogen addition extends the relaxation decay by approximately threefold, paving the way to bioimaging applications and beyond.

KW - anesthetic

KW - hydrogen

KW - hyperpolarization

KW - imaging agents

KW - neurochemistry

KW - parahydrogen

KW - PARA-HYDROGEN

KW - NUCLEAR-MAGNETIC-RESONANCE

KW - RESOLUTION

KW - HYPERPOLARIZED XENON

KW - SINGLET

KW - MOLECULES

KW - NMR

KW - XE-129

KW - METABOLISM

KW - LIVED SPIN STATES

UR - http://www.scopus.com/inward/record.url?scp=85091153048&partnerID=8YFLogxK

U2 - 10.1002/chem.202002528

DO - 10.1002/chem.202002528

M3 - Article

C2 - 32667687

AN - SCOPUS:85091153048

VL - 26

SP - 13621

EP - 13626

JO - Chemistry - A European Journal

JF - Chemistry - A European Journal

SN - 0947-6539

IS - 60

ER -