TY - JOUR

T1 - Constant-adiabaticity pulse schemes for manipulating singlet order in 3-spin systems with weak magnetic non-equivalence

AU - Rodin, Bogdan A.

AU - Kozinenko, Vitaly P.

AU - Kiryutin, Alexey S.

AU - Yurkovskaya, Alexandra V.

AU - Eills, James

AU - Ivanov, Konstantin L.

N1 - Funding Information: This work has been supported by the Russian Science Foundation (grant No. 20-62-47038). We acknowledge the Russian Ministry of Science and Higher Education for giving access to NMR facilities. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie Grant Agreement No. 766402. Konstantin L. Ivanov passed away on the 5th of March, 2021 at the age of 44, during the review process of this manuscript. He was a member of the Editorial Board of JMR and an excellent scientist who contributed to many fields of NMR spectroscopy. For his achievements in the SABRE and PHIP methods, he was awarded the Günther Laukien Prize in 2020. He was a very kind, smart, and good man, and his loss is a great grief for all of us. Publisher Copyright: © 2021 Elsevier Inc. Copyright: Copyright 2021 Elsevier B.V., All rights reserved.

PY - 2021/6

Y1 - 2021/6

N2 - Parahydrogen-induced polarization (PHIP) is a source of nuclear spin hyperpolarization, and this technique allows for the preparation of biomolecules for in vivo metabolic imaging. PHIP delivers hyperpolarization in the form of proton singlet order to a molecule, but most applications require that a heteronuclear (e.g. 13C or 15N) spin in the molecule is hyperpolarized. Here we present high field pulse methods to manipulate proton singlet order in the [1-13C]fumarate, and in particular to transfer the proton singlet order into 13C magnetization. We exploit adiabatic pulses, i.e., pulses with slowly ramped amplitude, and use constant-adiabaticity variants: the spin Hamiltonian is varied in such a way that the generalized adiabaticity parameter is time-independent. This allows for faster polarization transfer, and we achieve 96.2% transfer efficiency in thermal equilibrium experiments. We demonstrate this in experiments using hyperpolarization, and obtain 6.8% 13C polarization. This work paves the way for efficient hyperpolarization of nuclear spins in a variety of biomolecules, since the high-field pulse sequences allow individual spins to be addressed.

AB - Parahydrogen-induced polarization (PHIP) is a source of nuclear spin hyperpolarization, and this technique allows for the preparation of biomolecules for in vivo metabolic imaging. PHIP delivers hyperpolarization in the form of proton singlet order to a molecule, but most applications require that a heteronuclear (e.g. 13C or 15N) spin in the molecule is hyperpolarized. Here we present high field pulse methods to manipulate proton singlet order in the [1-13C]fumarate, and in particular to transfer the proton singlet order into 13C magnetization. We exploit adiabatic pulses, i.e., pulses with slowly ramped amplitude, and use constant-adiabaticity variants: the spin Hamiltonian is varied in such a way that the generalized adiabaticity parameter is time-independent. This allows for faster polarization transfer, and we achieve 96.2% transfer efficiency in thermal equilibrium experiments. We demonstrate this in experiments using hyperpolarization, and obtain 6.8% 13C polarization. This work paves the way for efficient hyperpolarization of nuclear spins in a variety of biomolecules, since the high-field pulse sequences allow individual spins to be addressed.

UR - http://www.scopus.com/inward/record.url?scp=85105064729&partnerID=8YFLogxK

U2 - 10.1016/j.jmr.2021.106978

DO - 10.1016/j.jmr.2021.106978

M3 - Article

C2 - 33957556

AN - SCOPUS:85105064729

VL - 327

JO - Journal of Magnetic Resonance

JF - Journal of Magnetic Resonance

SN - 1090-7807

M1 - 106978

ER -