1
|
Vaneeckhaute E, Tyburn J, Kempf JG, Martens JA, Breynaert E. Reversible Parahydrogen Induced Hyperpolarization of 15 N in Unmodified Amino Acids Unraveled at High Magnetic Field. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2207112. [PMID: 37211713 PMCID: PMC10427394 DOI: 10.1002/advs.202207112] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 05/02/2023] [Indexed: 05/23/2023]
Abstract
Amino acids (AAs) and ammonia are metabolic markers essential for nitrogen metabolism and cell regulation in both plants and humans. NMR provides interesting opportunities to investigate these metabolic pathways, yet lacks sensitivity, especially in case of 15 N. In this study, spin order embedded in p-H2 is used to produce on-demand reversible hyperpolarization in 15 N of pristine alanine and ammonia under ambient protic conditions directly in the NMR spectrometer. This is made possible by designing a mixed-ligand Ir-catalyst, selectively ligating the amino group of AA by exploiting ammonia as a strongly competitive co-ligand and preventing deactivation of Ir by bidentate ligation of AA. The stereoisomerism of the catalyst complexes is determined by hydride fingerprinting using 1 H/D scrambling of the associated N-functional groups on the catalyst (i.e., isotopological fingerprinting), and unravelled by 2D-ZQ-NMR. Monitoring the transfer of spin order from p-H2 to 15 N nuclei of ligated and free alanine and ammonia targets using SABRE-INEPT with variable exchange delays pinpoints the monodentate elucidated catalyst complexes to be most SABRE active. Also RF-spin locking (SABRE-SLIC) enables transfer of hyperpolarization to 15 N. The presented high-field approach can be a valuable alternative to SABRE-SHEATH techniques since the obtained catalytic insights (stereochemistry and kinetics) will remain valid at ultra-low magnetic fields.
Collapse
Affiliation(s)
- Ewoud Vaneeckhaute
- COK‐katCentre for Surface Chemistry and Catalysis—Characterization and Application TeamKU LeuvenCelestijnenlaan 200F, box 2461LeuvenB‐3001Belgium
- NMRCoReNMR/X‐Ray Platform for Convergence ResearchKU LeuvenCelestijnenlaan 200F, box 2461LeuvenB‐3001Belgium
- Univ LyonCNRS, ENS LyonUCBLUniversité de LyonCRMN UMR 5280Villeurbanne69100France
| | - Jean‐Max Tyburn
- Bruker Biospin34 Rue de l'Industrie BP 10002Wissembourg Cedex67166France
| | | | - Johan A. Martens
- COK‐katCentre for Surface Chemistry and Catalysis—Characterization and Application TeamKU LeuvenCelestijnenlaan 200F, box 2461LeuvenB‐3001Belgium
- NMRCoReNMR/X‐Ray Platform for Convergence ResearchKU LeuvenCelestijnenlaan 200F, box 2461LeuvenB‐3001Belgium
- Deutsches Elektronen‐Synchrotron DESY – Centre for Molecular Water Science (CMWS)Notkestraße 8522607HamburgGermany
| | - Eric Breynaert
- COK‐katCentre for Surface Chemistry and Catalysis—Characterization and Application TeamKU LeuvenCelestijnenlaan 200F, box 2461LeuvenB‐3001Belgium
- NMRCoReNMR/X‐Ray Platform for Convergence ResearchKU LeuvenCelestijnenlaan 200F, box 2461LeuvenB‐3001Belgium
| |
Collapse
|
2
|
Rayner PJ, Fekete M, Gater CA, Ahwal F, Turner N, Kennerley AJ, Duckett SB. Real-Time High-Sensitivity Reaction Monitoring of Important Nitrogen-Cycle Synthons by 15N Hyperpolarized Nuclear Magnetic Resonance. J Am Chem Soc 2022; 144:8756-8769. [PMID: 35508182 PMCID: PMC9121385 DOI: 10.1021/jacs.2c02619] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
Here, we show how
signal amplification by reversible exchange hyperpolarization
of a range of 15N-containing synthons can be used to enable
studies of their reactivity by 15N nuclear magnetic resonance
(NO2– (28% polarization), ND3 (3%), PhCH2NH2 (5%), NaN3 (3%),
and NO3– (0.1%)). A range of iridium-based
spin-polarization transfer catalysts are used, which for NO2– work optimally as an amino-derived carbene-containing
complex with a DMAP-d2 coligand. We harness
long 15N spin-order lifetimes to probe in situ reactivity
out to 3 × T1. In the case of NO2– (T1 17.7 s
at 9.4 T), we monitor PhNH2 diazotization in acidic solution.
The resulting diazonium salt (15N-T1 38 s) forms within 30 s, and its subsequent reaction with
NaN3 leads to the detection of hyperpolarized PhN3 (T1 192 s) in a second step via the
formation of an identified cyclic pentazole intermediate. The role
of PhN3 and NaN3 in copper-free click chemistry
is exemplified for hyperpolarized triazole (T1 < 10 s) formation when they react with a strained alkyne.
We also demonstrate simple routes to hyperpolarized N2 in
addition to showing how utilization of 15N-polarized PhCH2NH2 enables the probing of amidation, sulfonamidation,
and imine formation. Hyperpolarized ND3 is used to probe
imine and ND4+ (T1 33.6 s) formation. Furthermore, for NO2–, we also demonstrate how the 15N-magnetic resonance imaging
monitoring of biphasic catalysis confirms the successful preparation
of an aqueous bolus of hyperpolarized 15NO2– in seconds with 8% polarization. Hence, we create
a versatile tool to probe organic transformations that has significant
relevance for the synthesis of future hyperpolarized pharmaceuticals.
Collapse
Affiliation(s)
- Peter J Rayner
- Centre for Hyperpolarisation in Magnetic Resonance, Department of Chemistry, University of York, Heslington, York YO10 5DD, U.K
| | - Marianna Fekete
- Centre for Hyperpolarisation in Magnetic Resonance, Department of Chemistry, University of York, Heslington, York YO10 5DD, U.K
| | - Callum A Gater
- Centre for Hyperpolarisation in Magnetic Resonance, Department of Chemistry, University of York, Heslington, York YO10 5DD, U.K
| | - Fadi Ahwal
- Centre for Hyperpolarisation in Magnetic Resonance, Department of Chemistry, University of York, Heslington, York YO10 5DD, U.K
| | - Norman Turner
- Department of Engineering and Technology, University of Huddersfield, Queensgate, Huddersfield, West Yorkshire HD1 3DH, U.K
| | - Aneurin J Kennerley
- Centre for Hyperpolarisation in Magnetic Resonance, Department of Chemistry, University of York, Heslington, York YO10 5DD, U.K
| | - Simon B Duckett
- Centre for Hyperpolarisation in Magnetic Resonance, Department of Chemistry, University of York, Heslington, York YO10 5DD, U.K
| |
Collapse
|
3
|
Barker SJ, Dagys L, Hale W, Ripka B, Eills J, Sharma M, Levitt MH, Utz M. Direct Production of a Hyperpolarized Metabolite on a Microfluidic Chip. Anal Chem 2022; 94:3260-3267. [PMID: 35147413 PMCID: PMC9096798 DOI: 10.1021/acs.analchem.1c05030] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
![]()
Microfluidic systems hold great potential
for the study of live
microscopic cultures of cells, tissue samples, and small organisms.
Integration of hyperpolarization would enable quantitative studies
of metabolism in such volume limited systems by high-resolution NMR
spectroscopy. We demonstrate, for the first time, the integrated generation
and detection of a hyperpolarized metabolite on a microfluidic chip.
The metabolite [1-13C]fumarate is produced in a nuclear
hyperpolarized form by (i) introducing para-enriched hydrogen into
the solution by diffusion through a polymer membrane, (ii) reaction
with a substrate in the presence of a ruthenium-based catalyst, and
(iii) conversion of the singlet-polarized reaction product into a
magnetized form by the application of a radiofrequency pulse sequence,
all on the same microfluidic chip. The microfluidic device delivers
a continuous flow of hyperpolarized material at the 2.5 μL/min
scale, with a polarization level of 4%. We demonstrate two methods
for mitigating singlet–triplet mixing effects which otherwise
reduce the achieved polarization level.
Collapse
Affiliation(s)
- Sylwia J Barker
- School of Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Laurynas Dagys
- School of Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - William Hale
- School of Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom.,Department of Chemistry, University of Florida, Gainesville 32611, United States
| | - Barbara Ripka
- School of Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - James Eills
- Institute for Physics, Johannes Gutenberg University, D-55090 Mainz, Germany.,GSI Helmholtzzentrum für Schwerionenforschung GmbH, Helmholtz-Institut Mainz, 55128 Mainz, Germany
| | - Manvendra Sharma
- School of Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Malcolm H Levitt
- School of Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Marcel Utz
- School of Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom
| |
Collapse
|