1
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Jiang Y, Zhang X, Nie H, Fan J, Di S, Fu H, Zhang X, Wang L, Tang C. Dissecting diazirine photo-reaction mechanism for protein residue-specific cross-linking and distance mapping. Nat Commun 2024; 15:6060. [PMID: 39025860 PMCID: PMC11258254 DOI: 10.1038/s41467-024-50315-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2024] [Accepted: 07/08/2024] [Indexed: 07/20/2024] Open
Abstract
While photo-cross-linking (PXL) with alkyl diazirines can provide stringent distance restraints and offer insights into protein structures, unambiguous identification of cross-linked residues hinders data interpretation to the same level that has been achieved with chemical cross-linking (CXL). We address this challenge by developing an in-line system with systematic modulation of light intensity and irradiation time, which allows for a quantitative evaluation of diazirine photolysis and photo-reaction mechanism. Our results reveal a two-step pathway with mainly sequential generation of diazo and carbene intermediates. Diazo intermediate preferentially targets buried polar residues, many of which are inaccessible with known CXL probes for their limited reactivity. Moreover, we demonstrate that tuning light intensity and duration enhances selectivity towards polar residues by biasing diazo-mediated cross-linking reactions over carbene ones. This mechanistic dissection unlocks the full potential of PXL, paving the way for accurate distance mapping against protein structures and ultimately, unveiling protein dynamic behaviors.
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Affiliation(s)
- Yida Jiang
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
| | - Xinghe Zhang
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
| | - Honggang Nie
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
- Analytical Instrumentation Center, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
| | - Jianxiong Fan
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
| | - Shuangshuang Di
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
- Analytical Instrumentation Center, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
| | - Hui Fu
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
- Analytical Instrumentation Center, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
| | - Xiu Zhang
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
- Analytical Instrumentation Center, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
| | - Lijuan Wang
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
- Analytical Instrumentation Center, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
| | - Chun Tang
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing, China.
- Center for Quantitative Biology, PKU-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China.
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2
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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.
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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
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3
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Chen ZA, Rappsilber J. Protein structure dynamics by crosslinking mass spectrometry. Curr Opin Struct Biol 2023; 80:102599. [PMID: 37104977 DOI: 10.1016/j.sbi.2023.102599] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Revised: 03/22/2023] [Accepted: 03/27/2023] [Indexed: 04/29/2023]
Abstract
Crosslinking mass spectrometry captures protein structures in solution. The crosslinks reveal spatial proximities as distance restraints, but do not easily reveal which of these restraints derive from the same protein conformation. This superposition can be reduced by photo-crosslinking, and adding information from protein structure models, or quantitative crosslinking reveals conformation-specific crosslinks. As a consequence, crosslinking MS has proven useful already in the context of multiple dynamic protein systems. We foresee a breakthrough in the resolution and scale of studying protein dynamics when crosslinks are used to guide deep-learning-based protein modelling. Advances in crosslinking MS, such as photoactivatable crosslinking and in-situ crosslinking, will then reveal protein conformation dynamics in the cellular context, at a pseudo-atomic resolution, and plausibly in a time-resolved manner.
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Affiliation(s)
- Zhuo Angel Chen
- Technische Universität Berlin, Chair of Bioanalytics, 10623 Berlin, Germany
| | - Juri Rappsilber
- Technische Universität Berlin, Chair of Bioanalytics, 10623 Berlin, Germany; Si-M/"Der Simulierte Mensch", a Science Framework of Technische Universität Berlin and Charité - Universitätsmedizin Berlin, 10623 Berlin, Germany; Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh EH9 3BF, UK.
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4
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Deng L, Zhang C, Li B, Fu J, Zhang Z, Li S, Zhao X, Su Z, Hu C, Yu Z. Photo-induced defluorination acyl fluoride exchange as a fluorogenic photo-click reaction for photo-affinity labeling. Chem Sci 2023; 14:3630-3641. [PMID: 37006673 PMCID: PMC10056068 DOI: 10.1039/d2sc04636a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Accepted: 02/24/2023] [Indexed: 02/26/2023] Open
Abstract
Photo-click chemistry has emerged as a powerful tool for revolutionizing bioconjugation technologies in pharmacological and various biomimetic applications. However, enriching the photo-click reactions to expand the bioconjugation toolkit remains challenging, especially when focusing on spatiotemporal control endowed by light activation. Herein, we describe a photo-induced defluorination acyl fluoride exchange (photo-DAFEx) as a novel type of photo-click reaction that is mediated through acyl fluorides produced by the photo-defluorination of m-trifluoromethylaniline to covalently conjugate with primary/secondary amines and thiols in an aqueous environment. (TD)-DFT calculations, together with experimental discovery, indicate that the m-NH2PhF2C(sp3)-F bond in the excited triplet state is cleaved by water molecules, which is key to inducing defluorination. Intriguingly, the benzoyl amide linkages built by this photo-click reaction exhibited a satisfactory fluorogenic performance, which allowed visualization of its formation in situ. Accordingly, this photo-controlled covalent strategy was exploited not only for the decoration of small molecules, peptide cyclization and functionalization of proteins in vitro, but also for designing photo-affinity probes targeting endogenous carbonic anhydrase II (hCA-II) in living cells.
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Affiliation(s)
- Lijun Deng
- Key Laboratory of Green Chemistry & Technology of Ministry of Education, College of Chemistry, Sichuan University 29 Wangjiang Road Chengdu 610064 P. R. China
| | - Cefei Zhang
- Key Laboratory of Green Chemistry & Technology of Ministry of Education, College of Chemistry, Sichuan University 29 Wangjiang Road Chengdu 610064 P. R. China
| | - Baolin Li
- Key Laboratory of Green Chemistry & Technology of Ministry of Education, College of Chemistry, Sichuan University 29 Wangjiang Road Chengdu 610064 P. R. China
| | - Jielin Fu
- Key Laboratory of Green Chemistry & Technology of Ministry of Education, College of Chemistry, Sichuan University 29 Wangjiang Road Chengdu 610064 P. R. China
| | - Zhong Zhang
- Key Laboratory of Green Chemistry & Technology of Ministry of Education, College of Chemistry, Sichuan University 29 Wangjiang Road Chengdu 610064 P. R. China
| | - Sitong Li
- Key Laboratory of Green Chemistry & Technology of Ministry of Education, College of Chemistry, Sichuan University 29 Wangjiang Road Chengdu 610064 P. R. China
| | - Xiaohu Zhao
- Key Laboratory of Green Chemistry & Technology of Ministry of Education, College of Chemistry, Sichuan University 29 Wangjiang Road Chengdu 610064 P. R. China
| | - Zhishan Su
- Key Laboratory of Green Chemistry & Technology of Ministry of Education, College of Chemistry, Sichuan University 29 Wangjiang Road Chengdu 610064 P. R. China
| | - Changwei Hu
- Key Laboratory of Green Chemistry & Technology of Ministry of Education, College of Chemistry, Sichuan University 29 Wangjiang Road Chengdu 610064 P. R. China
| | - Zhipeng Yu
- Key Laboratory of Green Chemistry & Technology of Ministry of Education, College of Chemistry, Sichuan University 29 Wangjiang Road Chengdu 610064 P. R. China
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5
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Eills J, Budker D, Cavagnero S, Chekmenev EY, Elliott SJ, Jannin S, Lesage A, Matysik J, Meersmann T, Prisner T, Reimer JA, Yang H, Koptyug IV. Spin Hyperpolarization in Modern Magnetic Resonance. Chem Rev 2023; 123:1417-1551. [PMID: 36701528 PMCID: PMC9951229 DOI: 10.1021/acs.chemrev.2c00534] [Citation(s) in RCA: 62] [Impact Index Per Article: 62.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Magnetic resonance techniques are successfully utilized in a broad range of scientific disciplines and in various practical applications, with medical magnetic resonance imaging being the most widely known example. Currently, both fundamental and applied magnetic resonance are enjoying a major boost owing to the rapidly developing field of spin hyperpolarization. Hyperpolarization techniques are able to enhance signal intensities in magnetic resonance by several orders of magnitude, and thus to largely overcome its major disadvantage of relatively low sensitivity. This provides new impetus for existing applications of magnetic resonance and opens the gates to exciting new possibilities. In this review, we provide a unified picture of the many methods and techniques that fall under the umbrella term "hyperpolarization" but are currently seldom perceived as integral parts of the same field. Specifically, before delving into the individual techniques, we provide a detailed analysis of the underlying principles of spin hyperpolarization. We attempt to uncover and classify the origins of hyperpolarization, to establish its sources and the specific mechanisms that enable the flow of polarization from a source to the target spins. We then give a more detailed analysis of individual hyperpolarization techniques: the mechanisms by which they work, fundamental and technical requirements, characteristic applications, unresolved issues, and possible future directions. We are seeing a continuous growth of activity in the field of spin hyperpolarization, and we expect the field to flourish as new and improved hyperpolarization techniques are implemented. Some key areas for development are in prolonging polarization lifetimes, making hyperpolarization techniques more generally applicable to chemical/biological systems, reducing the technical and equipment requirements, and creating more efficient excitation and detection schemes. We hope this review will facilitate the sharing of knowledge between subfields within the broad topic of hyperpolarization, to help overcome existing challenges in magnetic resonance and enable novel applications.
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Affiliation(s)
- James Eills
- Institute
for Bioengineering of Catalonia, Barcelona
Institute of Science and Technology, 08028Barcelona, Spain,
| | - Dmitry Budker
- Johannes
Gutenberg-Universität Mainz, 55128Mainz, Germany,Helmholtz-Institut,
GSI Helmholtzzentrum für Schwerionenforschung, 55128Mainz, Germany,Department
of Physics, UC Berkeley, Berkeley, California94720, United States
| | - Silvia Cavagnero
- Department
of Chemistry, University of Wisconsin, Madison, Madison, Wisconsin53706, United States
| | - Eduard Y. Chekmenev
- Department
of Chemistry, Integrative Biosciences (IBio), Karmanos Cancer Institute
(KCI), Wayne State University, Detroit, Michigan48202, United States,Russian
Academy of Sciences, Moscow119991, Russia
| | - Stuart J. Elliott
- Molecular
Sciences Research Hub, Imperial College
London, LondonW12 0BZ, United Kingdom
| | - Sami Jannin
- Centre
de RMN à Hauts Champs de Lyon, Université
de Lyon, CNRS, ENS Lyon, Université Lyon 1, 69100Villeurbanne, France
| | - Anne Lesage
- Centre
de RMN à Hauts Champs de Lyon, Université
de Lyon, CNRS, ENS Lyon, Université Lyon 1, 69100Villeurbanne, France
| | - Jörg Matysik
- Institut
für Analytische Chemie, Universität
Leipzig, Linnéstr. 3, 04103Leipzig, Germany
| | - Thomas Meersmann
- Sir
Peter Mansfield Imaging Centre, University Park, School of Medicine, University of Nottingham, NottinghamNG7 2RD, United Kingdom
| | - Thomas Prisner
- Institute
of Physical and Theoretical Chemistry and Center of Biomolecular Magnetic
Resonance, Goethe University Frankfurt, , 60438Frankfurt
am Main, Germany
| | - Jeffrey A. Reimer
- Department
of Chemical and Biomolecular Engineering, UC Berkeley, and Materials Science Division, Lawrence Berkeley National
Laboratory, Berkeley, California94720, United States
| | - Hanming Yang
- Department
of Chemistry, University of Wisconsin, Madison, Madison, Wisconsin53706, United States
| | - Igor V. Koptyug
- International Tomography Center, Siberian
Branch of the Russian Academy
of Sciences, 630090Novosibirsk, Russia,
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6
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Sonnefeld A, Razanahoera A, Pelupessy P, Bodenhausen G, Sheberstov K. Long-lived states of methylene protons in achiral molecules. SCIENCE ADVANCES 2022; 8:eade2113. [PMID: 36459545 PMCID: PMC10936052 DOI: 10.1126/sciadv.ade2113] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 10/19/2022] [Indexed: 06/17/2023]
Abstract
In nuclear magnetic resonance (NMR), the lifetimes of long-lived states (LLSs) are exquisitely sensitive to their environment. However, the number of molecules where such states can be excited has hitherto been rather limited. Here, it is shown that LLSs can be readily excited in many common molecules that contain two or more neighboring CH2 groups. Accessing such LLSs does not require any isotopic enrichment, nor does it require any stereogenic centers to lift the chemical equivalence of CH2 protons. LLSs were excited in a variety of metabolites, neurotransmitters, vitamins, amino acids, and other molecules. One can excite LLSs in several different molecules simultaneously. In combination with magnetic resonance imaging, LLSs can reveal a contrast upon noncovalent binding of ligands to macromolecules. This suggests new perspectives to achieve high-throughput parallel drug screening by NMR.
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Affiliation(s)
- Anna Sonnefeld
- Department of chemistry, École Normale Supérieure, PSL University, Paris, France
| | - Aiky Razanahoera
- Department of chemistry, École Normale Supérieure, PSL University, Paris, France
| | - Philippe Pelupessy
- Department of chemistry, École Normale Supérieure, PSL University, Paris, France
| | | | - Kirill Sheberstov
- Department of chemistry, École Normale Supérieure, PSL University, Paris, France
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7
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West AV, Woo CM. Photoaffinity Labeling Chemistries Used to Map Biomolecular Interactions. Isr J Chem 2022. [DOI: 10.1002/ijch.202200081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Alexander V. West
- Department of Chemistry and Chemical Biology Harvard University 12 Oxford St Cambridge MA USA
| | - Christina M. Woo
- Department of Chemistry and Chemical Biology Harvard University 12 Oxford St Cambridge MA USA
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8
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Bera PP, Noneman KK, Lee TJ. Energy Landscape and Structural and Spectroscopic Characterization of Diazirine and Its Cyclic Isomers. J Phys Chem A 2022; 126:4700-4708. [PMID: 35853204 DOI: 10.1021/acs.jpca.2c01444] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Identifying new nitrogenated hydrocarbon molecules in the interstellar medium (ISM) is challenging because of the lack of comprehensive spectroscopic data from experiments. In this computational work, we focus on investigating the structures, relative energies, spectroscopic constants, and energy landscape of the cyclic isomers of diazirine (c-CH2N2) using ab initio quantum chemical methods. Density functional theory (DFT) methods and coupled cluster theory with singles and doubles including perturbative triples [CCSD(T)] and CCSD(T) with the explicitly correlated F12b correction [CCSD(T)-F12b] were employed for this purpose along with large correlation consistent cc-pVTZ, cc-pVQZ, and cc-pV5Z basis sets. Harmonic vibrational frequencies, infrared vibrational intensities, rotational constants, and dipole moments are reported. Anharmonic vibrational fundamentals along with centrifugal distortion constants, and vibration-rotation interaction constants are also reported for all the cyclic isomers. The energies computed with the CCSD(T) and CCSD(T)-F12b methods were extrapolated to the one-particle complete basis set (CBS) limit following a three-point formula. At the CCSD(T)-F12b/CBS level of theory, the 3,3H-diazirine (c-CH2N2) is the lowest energy cyclic isomer followed by 1,3H-diazirine, (E)-1,2H-diazirine, and (Z)-1,2H-diazirine, which are 20.1, 47.8, and 51.3 kcal mol-1 above the 3,3H-diazirine, respectively. Accurate structures and spectroscopic constants that are reported here could be useful for future identification of these cyclic nitrogenated organic molecules in the interstellar medium or circumstellar disks.
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Affiliation(s)
- Partha P Bera
- Bay Area Environmental Research Institute, Moffett Field, California 94035, United States
- Space Science and Astrobiology Division, NASA Ames Research Center, Mountain View, California 94035, United States
| | - Kendra K Noneman
- Space Science and Astrobiology Division, NASA Ames Research Center, Mountain View, California 94035, United States
- Micron School of Materials Science and Engineering, Boise State University, 1910 University Drive, Boise, Idaho 83725, United States
| | - Timothy J Lee
- Space Science and Astrobiology Division, NASA Ames Research Center, Mountain View, California 94035, United States
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9
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Tickner BJ, Zhivonitko VV. Advancing homogeneous catalysis for parahydrogen-derived hyperpolarisation and its NMR applications. Chem Sci 2022; 13:4670-4696. [PMID: 35655870 PMCID: PMC9067625 DOI: 10.1039/d2sc00737a] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2022] [Accepted: 03/21/2022] [Indexed: 12/18/2022] Open
Abstract
Parahydrogen-induced polarisation (PHIP) is a nuclear spin hyperpolarisation technique employed to enhance NMR signals for a wide range of molecules. This is achieved by exploiting the chemical reactions of parahydrogen (para-H2), the spin-0 isomer of H2. These reactions break the molecular symmetry of para-H2 in a way that can produce dramatically enhanced NMR signals for reaction products, and are usually catalysed by a transition metal complex. In this review, we discuss recent advances in novel homogeneous catalysts that can produce hyperpolarised products upon reaction with para-H2. We also discuss hyperpolarisation attained in reversible reactions (termed signal amplification by reversible exchange, SABRE) and focus on catalyst developments in recent years that have allowed hyperpolarisation of a wider range of target molecules. In particular, recent examples of novel ruthenium catalysts for trans and geminal hydrogenation, metal-free catalysts, iridium sulfoxide-containing SABRE systems, and cobalt complexes for PHIP and SABRE are reviewed. Advances in this catalysis have expanded the types of molecules amenable to hyperpolarisation using PHIP and SABRE, and their applications in NMR reaction monitoring, mechanistic elucidation, biomedical imaging, and many other areas, are increasing.
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Affiliation(s)
- Ben J Tickner
- NMR Research Unit, Faculty of Science, University of Oulu P.O. Box 3000 Oulu 90014 Finland
- Department of Chemical and Biological Physics, Faculty of Chemistry, Weizmann Institute of Science Rehovot 7610001 Israel
| | - Vladimir V Zhivonitko
- NMR Research Unit, Faculty of Science, University of Oulu P.O. Box 3000 Oulu 90014 Finland
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10
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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.
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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
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11
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Jamshaid S, Lee YR. Lewis-Acid-Catalyzed Regioselective Construction of Diversely Functionalized Polycyclic Fused Furans. Org Lett 2022; 24:1351-1356. [PMID: 35118858 DOI: 10.1021/acs.orglett.2c00019] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A novel, facile, and efficient Lewis-acid-catalyzed [4 + 1] annulation protocol for the construction of functionalized polycyclic-fused furans is developed. This methodology is free of transition metals and ligands and provides a rapid synthetic route to divergently orientated polycyclic furans in good yields. In addition, this protocol can also be used to synthesize multisubstituted furans.
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Affiliation(s)
- Sana Jamshaid
- School of Chemical Engineering, Yeungnam University, Gyeongsan 38541, Republic of Korea
| | - Yong Rok Lee
- School of Chemical Engineering, Yeungnam University, Gyeongsan 38541, Republic of Korea
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12
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Glöggler S, Yang S, Saul P, Mamone S, Kaltschnee L. Bimodal fluorescence/magnetic resonance molecular probes with extended spin lifetimes. Chemistry 2021; 28:e202104158. [PMID: 34854145 PMCID: PMC9302690 DOI: 10.1002/chem.202104158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Indexed: 11/12/2022]
Abstract
Bimodal molecular probes combining nuclear magnetic resonance (NMR) and fluorescence have been widely studied in basic science, as well as clinical research. The investigation of spin phenomena holds promise to broaden the scope of available probes allowing deeper insights into physiological processes. Herein, a class of molecules with a bimodal character with respect to fluorescence and nuclear spin singlet states is introduced. Singlet states are NMR silent but can be probed indirectly. Symmetric, perdeuterated molecules, in which the singlet states can be populated by vanishingly small electron‐mediated couplings (below 1 Hz) are reported. The lifetimes of these states are an order of magnitude longer than the longitudinal relaxation times and up to four minutes at 7 T. Moreover, these molecules show either aggregation induced emission (AIE) or aggregation caused quenching (ACQ) with respect to their fluorescence. In the latter case, the existence of excited dimers, which are proposed to use in a switchable manner in combination with the quenching of nuclear spin singlet states, is observed
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Affiliation(s)
- Stefan Glöggler
- Max-Planck-Institute for Biophysical Chemistry, NMR Signal Enhancement Group, Am Fassberg 11, 37077, Göttingen, GERMANY
| | - Shengjun Yang
- Max-Planck-Institute for Biophysical Chemistry: Max-Planck-Institut fur biophysikalische Chemie, NMR Signal Enhancement, GERMANY
| | - Philip Saul
- Max-Planck-Institute for Biophysical Chemistry: Max-Planck-Institut fur biophysikalische Chemie, NMR Singal Enhancement, GERMANY
| | - Salvatore Mamone
- Max-Planck-Institute for Biophysical Chemistry: Max-Planck-Institut fur biophysikalische Chemie, NMR Signal Enhancement, GERMANY
| | - Lukas Kaltschnee
- Max-Planck-Institute for Biophysical Chemistry: Max-Planck-Institut fur biophysikalische Chemie, NMR Signal Enhancement, GERMANY
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13
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Chukanov NV, Shchepin RV, Joshi SM, Kabir MSH, Salnikov OG, Svyatova A, Koptyug IV, Gelovani JG, Chekmenev EY. Synthetic Approaches for 15 N-Labeled Hyperpolarized Heterocyclic Molecular Imaging Agents for 15 N NMR Signal Amplification by Reversible Exchange in Microtesla Magnetic Fields. Chemistry 2021; 27:9727-9736. [PMID: 33856077 PMCID: PMC8273115 DOI: 10.1002/chem.202100212] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Indexed: 12/23/2022]
Abstract
NMR hyperpolarization techniques enhance nuclear spin polarization by several orders of magnitude resulting in corresponding sensitivity gains. This enormous sensitivity gain enables new applications ranging from studies of small molecules by using high-resolution NMR spectroscopy to real-time metabolic imaging in vivo. Several hyperpolarization techniques exist for hyperpolarization of a large repertoire of nuclear spins, although the 13 C and 15 N sites of biocompatible agents are the key targets due to their widespread use in biochemical pathways. Moreover, their long T1 allows hyperpolarized states to be retained for up to tens of minutes. Signal amplification by reversible exchange (SABRE) is a low-cost and ultrafast hyperpolarization technique that has been shown to be versatile for the hyperpolarization of 15 N nuclei. Although large sensitivity gains are enabled by hyperpolarization, 15 N natural abundance is only ∼0.4 %, so isotopic labeling of the molecules to be hyperpolarized is required in order to take full advantage of the hyperpolarized state. Herein, we describe selected advances in the preparation of 15 N-labeled compounds with the primary emphasis on using these compounds for SABRE polarization in microtesla magnetic fields through spontaneous polarization transfer from parahydrogen. Also, these principles can certainly be applied for hyperpolarization of these emerging contrast agents using dynamic nuclear polarization and other techniques.
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Affiliation(s)
- Nikita V Chukanov
- International Tomography Center, SB RAS, Institutskaya St. 3A, 630090, Novosibirsk, Russia
- Department of Natural Sciences, Novosibirsk State University, Pirogova St. 2, 630090, Novosibirsk, Russia
| | - Roman V Shchepin
- Department of Chemistry, Biology, and Health Sciences, South Dakota School of Mines & Technology, Rapid City, SD 57701, USA
| | - Sameer M Joshi
- Department of Chemistry, Integrative Biosciences (Ibio), Karmanos Cancer Institute (KCI), Wayne State University, Detroit, MI 48202, USA
| | - Mohammad S H Kabir
- Department of Chemistry, Integrative Biosciences (Ibio), Karmanos Cancer Institute (KCI), Wayne State University, Detroit, MI 48202, USA
| | - Oleg G Salnikov
- International Tomography Center, SB RAS, Institutskaya St. 3A, 630090, Novosibirsk, Russia
- Department of Natural Sciences, Novosibirsk State University, Pirogova St. 2, 630090, Novosibirsk, Russia
- Boreskov Institute of Catalysis SB RAS, Acad. Lavrentiev Prospekt 5, 630090, Novosibirsk, Russia
| | - Alexandra Svyatova
- International Tomography Center, SB RAS, Institutskaya St. 3A, 630090, Novosibirsk, Russia
- Department of Natural Sciences, Novosibirsk State University, Pirogova St. 2, 630090, Novosibirsk, Russia
| | - Igor V Koptyug
- International Tomography Center, SB RAS, Institutskaya St. 3A, 630090, Novosibirsk, Russia
| | - Juri G Gelovani
- Department of Chemistry, Integrative Biosciences (Ibio), Karmanos Cancer Institute (KCI), Wayne State University, Detroit, MI 48202, USA
- College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, UAE
| | - Eduard Y Chekmenev
- Department of Chemistry, Integrative Biosciences (Ibio), Karmanos Cancer Institute (KCI), Wayne State University, Detroit, MI 48202, USA
- Russian Academy of Sciences (RAS), Leninskiy Prospekt 14, 119991, Moscow, Russia
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14
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Ondrus AE, Zhang T. Structure, Bonding, and Photoaffinity Labeling Applications of Dialkyldiazirines. Synlett 2021. [DOI: 10.1055/a-1437-8202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
AbstractDialkyldiazirine photoaffinity probes are unparalleled tools for the study of small molecule–protein interactions. Here we summarize the basic principles of structure, bonding, and photoreactivity of dialkyldiazirines, current methods for their synthesis, and their practical application in photoaffinity labeling experiments. We demonstrate the unique utility of dialkyldiazirine probes in the context of our recent photoaffinity crosslinking-mass spectrometry analysis to reveal a hidden cholesterol binding site in the Hedgehog morphogen proteins.1 Introduction2 Structure, Bonding, and Spectral Properties3 Photoreactivity4 Synthesis5 Application in Photoaffinity Labeling6 Discovery of a Cholesterol–Hedgehog Protein Interface7 Conclusions and Outlook
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15
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Abstract
Nuclear long-lived spin states represent spin density operator configurations that are exceptionally well protected against spin relaxation phenomena. Their long-lived character is exploited in a variety of Nuclear Magnetic Resonance (NMR) techniques. Despite the growing importance of long-lived spin states in modern NMR, strategies for their identification have changed little over the last decade. The standard approach heavily relies on a chain of group theoretical arguments. In this paper, we present a more streamlined method for the calculation of such configurations. Instead of focusing on the symmetry properties of the relaxation superoperator, we focus on its corresponding relaxation algebra. This enables us to analyze long-lived spin states with Lie algebraic methods rather than group theoretical arguments. We show that the centralizer of the relaxation algebra forms a basis for the set of long-lived spin states. The characterization of the centralizer, on the other hand, does not rely on any special symmetry arguments, and its calculation is straightforward. We outline a basic algorithm and illustrate advantages by considering long-lived spin states for some spin-1/2 pairs and rapidly rotating methyl groups.
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Affiliation(s)
- Christian Bengs
- School of Chemistry, School of Chemistry, University of Southampton, University Road, Southampton, SO17 1BJ United Kingdom
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16
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West AV, Muncipinto G, Wu HY, Huang AC, Labenski MT, Jones LH, Woo CM. Labeling Preferences of Diazirines with Protein Biomolecules. J Am Chem Soc 2021; 143:6691-6700. [PMID: 33876925 DOI: 10.1021/jacs.1c02509] [Citation(s) in RCA: 90] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Diazirines are widely used in photoaffinity labeling (PAL) to trap noncovalent interactions with biomolecules. However, design and interpretation of PAL experiments is challenging without a molecular understanding of the reactivity of diazirines with protein biomolecules. Herein, we report a systematic evaluation of the labeling preferences of alkyl and aryl diazirines with individual amino acids, single proteins, and in the whole cell proteome. We find that alkyl diazirines exhibit preferential labeling of acidic amino acids in a pH-dependent manner that is characteristic of a reactive alkyl diazo intermediate, while the aryl-fluorodiazirine labeling pattern reflects reaction primarily through a carbene intermediate. From a survey of 32 alkyl diazirine probes, we use this reactivity profile to rationalize why alkyl diazirine probes preferentially enrich highly acidic proteins or those embedded in membranes and why probes with a net positive charge tend to produce higher labeling yields in cells and in vitro. These results indicate that alkyl diazirines are an especially effective chemistry for surveying the membrane proteome and will facilitate design and interpretation of biomolecular labeling experiments with diazirines.
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Affiliation(s)
- Alexander V West
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
| | | | - Hung-Yi Wu
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Andrew C Huang
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
| | | | - Lyn H Jones
- Dana-Farber Cancer Institute, 360 Longwood Avenue, Boston, Massachusetts 02215, United States
| | - Christina M Woo
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
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17
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Yang J, Wang G, Chen S, Ma B, Zhou H, Song M, Liu C, Huo C. Catalyst-free, visible-light-promoted S-H insertion reaction between thiols and α-diazoesters. Org Biomol Chem 2020; 18:9494-9498. [PMID: 33180081 DOI: 10.1039/d0ob02006k] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
A visible-light-promoted S-H insertion reaction between thiols and α-diazoesters was developed. The reaction proceeded smoothly at room temperature with a broad substrate scope, affording various thioethers in moderate to excellent yields. The catalyst- and additive-free nature, sustainable energy source and mild reaction conditions make this strategy more eco-friendly.
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Affiliation(s)
- Jingya Yang
- College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, China.
| | - Ganggang Wang
- College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, China.
| | - Shuwen Chen
- College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, China.
| | - Ben Ma
- College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, China.
| | - Hongyan Zhou
- College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, China. and College of Science, Gansu Agricultural University, Lanzhou 730070, China
| | - Menghui Song
- College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, China.
| | - Cai Liu
- College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, China.
| | - Congde Huo
- College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, China.
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18
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Bengs C, Dagys L, Levitt MH. Robust transformation of singlet order into heteronuclear magnetisation over an extended coupling range. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2020; 321:106850. [PMID: 33190080 DOI: 10.1016/j.jmr.2020.106850] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 10/06/2020] [Accepted: 10/09/2020] [Indexed: 06/11/2023]
Abstract
Several important NMR procedures involve the conversion of nuclear singlet order into heteronuclear magnetisation, including some experiments involving long-lived spin states and parahydrogen-induced hyperpolarisation. However most existing sequences suffer from a limited range of validity or a lack of robustness against experimental imperfections. We present a new radio-frequency scheme for the transformation of the singlet order of a chemically-equivalent homonuclear spin pair into the magnetisation of a heteronuclear coupling partner. The proposed radio-frequency (RF) scheme is called gS2hM (generalized singlet-to-heteronuclear magnetisation) and has good compensation for common experimental errors such as RF and static field inhomogeneities. The sequence retains its robustness for homonuclear spin pairs in the intermediate coupling regime, characterised by the in-pair coupling being of the same order of magnitude as the difference between the out-of-pair couplings. This is a substantial improvement to the validity range of existing sequences. Analytical solutions for the pulse sequence parameters are provided. Experimental results are shown for two test cases.
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Affiliation(s)
- Christian Bengs
- School of Chemistry, Southampton University, University Road, SO17 1BJ, UK.
| | - Laurynas Dagys
- School of Chemistry, Southampton University, University Road, SO17 1BJ, UK.
| | - Malcolm H Levitt
- School of Chemistry, Southampton University, University Road, SO17 1BJ, UK.
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19
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Kovtunov KV, Koptyug IV, Fekete M, Duckett SB, Theis T, Joalland B, Chekmenev EY. Parawasserstoff‐induzierte Hyperpolarisation von Gasen. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.201915306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Kirill V. Kovtunov
- International Tomography Center SB RAS 630090 Novosibirsk Russland
- Department of Natural Sciences Novosibirsk State University Pirogova St. 2 630090 Novosibirsk Russland
| | - Igor V. Koptyug
- International Tomography Center SB RAS 630090 Novosibirsk Russland
- Department of Natural Sciences Novosibirsk State University Pirogova St. 2 630090 Novosibirsk Russland
| | - Marianna Fekete
- Center for Hyperpolarization in Magnetic Resonance (CHyM) University of York Heslington York YO10 5NY UK
| | - Simon B. Duckett
- Center for Hyperpolarization in Magnetic Resonance (CHyM) University of York Heslington York YO10 5NY UK
| | - Thomas Theis
- Department of Chemistry North Carolina State University Raleigh North Carolina 27695-8204 USA
| | - Baptiste Joalland
- Department of Chemistry Integrative Biosciences (Ibio) Karmanos Cancer Institute (KCI) Wayne State University Detroit Michigan 48202 USA
| | - Eduard Y. Chekmenev
- Department of Chemistry Integrative Biosciences (Ibio) Karmanos Cancer Institute (KCI) Wayne State University Detroit Michigan 48202 USA
- Russian Academy of Sciences (RAS) Leninskiy Prospekt 14 Moscow 119991 Russland
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20
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Kovtunov KV, Koptyug IV, Fekete M, Duckett SB, Theis T, Joalland B, Chekmenev EY. Parahydrogen-Induced Hyperpolarization of Gases. Angew Chem Int Ed Engl 2020; 59:17788-17797. [PMID: 31972061 PMCID: PMC7453723 DOI: 10.1002/anie.201915306] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Indexed: 12/16/2022]
Abstract
Imaging of gases is a major challenge for any modality including MRI. NMR and MRI signals are directly proportional to the nuclear spin density and the degree of alignment of nuclear spins with applied static magnetic field, which is called nuclear spin polarization. The level of nuclear spin polarization is typically very low, i.e., one hundred thousandth of the potential maximum at 1.5 T and a physiologically relevant temperature. As a result, MRI typically focusses on imaging highly concentrated tissue water. Hyperpolarization methods transiently increase nuclear spin polarizations up to unity, yielding corresponding gains in MRI signal level of several orders of magnitude that enable the 3D imaging of dilute biomolecules including gases. Parahydrogen-induced polarization is a fast, highly scalable, and low-cost hyperpolarization technique. The focus of this Minireview is to highlight selected advances in the field of parahydrogen-induced polarization for the production of hyperpolarized compounds, which can be potentially employed as inhalable contrast agents.
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Affiliation(s)
- Kirill V Kovtunov
- International Tomography Center, SB RAS, 630090, Novosibirsk, Russia
- Department of Natural Sciences, Novosibirsk State University, Pirogova St. 2, 630090, Novosibirsk, Russia
| | - Igor V Koptyug
- International Tomography Center, SB RAS, 630090, Novosibirsk, Russia
- Department of Natural Sciences, Novosibirsk State University, Pirogova St. 2, 630090, Novosibirsk, Russia
| | - Marianna Fekete
- Center for Hyperpolarization in Magnetic Resonance (CHyM), University of York, Heslington, York, YO10 5NY, UK
| | - Simon B Duckett
- Center for Hyperpolarization in Magnetic Resonance (CHyM), University of York, Heslington, York, YO10 5NY, UK
| | - Thomas Theis
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina, 27695-8204, USA
| | - Baptiste Joalland
- Department of Chemistry, Integrative Biosciences (Ibio), Karmanos Cancer Institute (KCI), Wayne State University, Detroit, Michigan, 48202, USA
| | - Eduard Y Chekmenev
- Department of Chemistry, Integrative Biosciences (Ibio), Karmanos Cancer Institute (KCI), Wayne State University, Detroit, Michigan, 48202, USA
- Russian Academy of Sciences (RAS), Leninskiy Prospekt 14, Moscow, 119991, Russia
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21
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Yang J, Duan J, Wang G, Zhou H, Ma B, Wu C, Xiao J. Visible-Light-Promoted Site-Selective N1-Alkylation of Benzotriazoles with α-Diazoacetates. Org Lett 2020; 22:7284-7289. [DOI: 10.1021/acs.orglett.0c02619] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Jingya Yang
- College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, China
| | - Jiaokui Duan
- College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, China
| | - Ganggang Wang
- College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, China
| | - Hongyan Zhou
- College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, China
- College of Science, Gansu Agricultural University, Lanzhou 730070, China
| | - Ben Ma
- College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, China
| | - Chengqi Wu
- College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, China
| | - Jianliang Xiao
- Department of Chemistry, University of Liverpool, Liverpool L69 7ZD, United Kingdom
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22
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Roy SS, Rayner PJ, Burns MJ, Duckett SB. A simple and cost-efficient technique to generate hyperpolarized long-lived 15N- 15N nuclear spin order in a diazine by signal amplification by reversible exchange. J Chem Phys 2020; 152:014201. [PMID: 31914733 PMCID: PMC7351221 DOI: 10.1063/1.5132308] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Signal Amplification by Reversible Exchange (SABRE) is an inexpensive and simple hyperpolarization technique that is capable of boosting nuclear magnetic resonance sensitivity by several orders of magnitude. It utilizes the reversible binding of para-hydrogen, as hydride ligands, and a substrate of interest to a metal catalyst to allow for polarization transfer from para-hydrogen into substrate nuclear spins. While the resulting nuclear spin populations can be dramatically larger than those normally created, their lifetime sets a strict upper limit on the experimental timeframe. Consequently, short nuclear spin lifetimes are a challenge for hyperpolarized metabolic imaging. In this report, we demonstrate how both hyperpolarization and long nuclear spin lifetime can be simultaneously achieved in nitrogen-15 containing derivatives of pyridazine and phthalazine by SABRE. These substrates were chosen to reflect two distinct classes of 15N2-coupled species that differ according to their chemical symmetry and thereby achieve different nuclear spin lifetimes. The pyridazine derivative proves to exhibit a signal lifetime of ∼2.5 min and can be produced with a signal enhancement of ∼2700. In contrast, while the phthalazine derivative yields a superior 15 000-fold 15N signal enhancement at 11.7 T, it has a much shorter signal lifetime.
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Affiliation(s)
- Soumya S Roy
- Centre for Hyperpolarisation in Magnetic Resonance (CHyM), Department of Chemistry, University of York, Heslington, York YO10 5DD, United Kingdom
| | - Peter J Rayner
- Centre for Hyperpolarisation in Magnetic Resonance (CHyM), Department of Chemistry, University of York, Heslington, York YO10 5DD, United Kingdom
| | - Michael J Burns
- Centre for Hyperpolarisation in Magnetic Resonance (CHyM), Department of Chemistry, University of York, Heslington, York YO10 5DD, United Kingdom
| | - Simon B Duckett
- Centre for Hyperpolarisation in Magnetic Resonance (CHyM), Department of Chemistry, University of York, Heslington, York YO10 5DD, United Kingdom
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23
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Levitt MH. Long live the singlet state! JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2019; 306:69-74. [PMID: 31307892 DOI: 10.1016/j.jmr.2019.07.029] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2019] [Revised: 03/30/2019] [Accepted: 07/08/2019] [Indexed: 06/10/2023]
Abstract
The field of long-lived states in NMR is reviewed. The relationship of long-lived-state phenomena to those associated with spin isomerism is discussed. A brief overview is given of key developments in the field of long-lived states, including chemical symmetry-switching, the role of magnetic equivalence and magnetic inequivalence, long-lived coherences, hyperpolarized NMR involving long-lived states, quantum-rotor-induced polarization, and parahydrogen-induced hyperpolarization. Current application areas of long-lived states are reviewed, and a peer into the crystal ball reveals future developments in the field.
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Affiliation(s)
- Malcolm H Levitt
- School of Chemistry, University of Southampton, University Road, SO17 1BJ Southampton, UK.
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