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Gangwar U, Kurur ND. Relaxation Editing in NMR Using a New Two-Dimensional Long-Lived Coherence Method for Mixture Analysis. Anal Chem 2024; 96:8399-8405. [PMID: 38727639 DOI: 10.1021/acs.analchem.3c05574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
The exploration of metabolomics and targeted segments of proteins stands as a pivotal facet of Nuclear Magnetic Resonance (NMR) analysis, furnishing valuable insights into molecular architectures and potential therapeutic applications. The issue of spectral congestion frequently presents challenges in ascribing distinct peaks within the confines of both one-dimensional (1D) and two-dimensional (2D) NMR spectra. Numerous strategies have been proposed to resolve specific resonances in NMR spectra differentially. Among these approaches, relaxation editing emerges as a viable solution. In the realm of relaxation phenomena within NMR, Long-Lived States (LLS) and Long-Lived Coherences (LLC) manifest as promising phenomena, offering enhanced relaxation lifetimes in comparison to the traditional longitudinal (T1) and transverse (T2) relaxation times for coupled nuclear spins. Notably, LLC presents a pathway to attenuate uncoupled high-intensity peaks, effectively diminishing their impact. The foundation of this technique rests upon the premise that the relaxation lifetime in the rotating frame (T1ρ) remains smaller than TLLC. In pursuit of refining spectral assignments within complex mixtures, we introduce a new pulse sequence tailored for LLC Total Correlation Spectroscopy (LLC-TOCSY). This demonstrates efficacy in extracting LLC signals within configurations involving multiple coupled spins, thereby decluttering the spectrum and enhancing the accuracy of peak assignments. To validate the effectiveness of this method, a collection of samples was subjected to scrutiny, yielding compelling results.
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Affiliation(s)
- Upanshu Gangwar
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| | - Narayanan D Kurur
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
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2
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Ianc O, Teleanu F, Ciumeică A, Lupulescu A, Sadet A, Vasos PR. Improved detection of magnetic interactions in proteins based on long-lived coherences. Commun Chem 2024; 7:112. [PMID: 38755276 PMCID: PMC11099074 DOI: 10.1038/s42004-024-01195-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Accepted: 04/30/2024] [Indexed: 05/18/2024] Open
Abstract
Living systems rely on molecular building blocks with low structural symmetry. Therefore, constituent amino acids and nucleotides yield short-lived nuclear magnetic responses to electromagnetic radiation. Magnetic signals are at the basis of molecular imaging, structure determination and interaction studies. In solution state, as the molecular weight of analytes increases, coherences with long lifetimes are needed to yield advantageous through-space magnetisation transfers. Interactions between magnetic nuclei can only be detected provided the lifetimes of spin order are sufficient. In J-coupled pairs of nuclei, long-lived coherences (LLC's) connect states with different spin-permutation symmetry. Here in, we show sustained LLC's in protein Lysozyme, weighing 14.3 kDa, with lifetimes twice as long as those of classical magnetisation for the aliphatic protons of glycine residues. We found for the first time that, in a protein of significant molecular weight, LLC's yield substantial through-space magnetisation transfers: spin-order transfer stemming from LLC's overcame transfers from classical coherences by factors > 2. Furthermore, in agreement with theory, the permutation symmetry of LLC-based transfers allows mapping interacting atoms in the protein structure with respect to the molecular plane of glycine residues in a stereospecific manner. These findings can extend the scope of liquid-state high-resolution biomolecular spectroscopy.
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Affiliation(s)
- Octavian Ianc
- Biophysics and Biomedical Applications Laboratory and Group, LGED, ELI-NP, "Horia Hulubei" National Institute for Physics and Nuclear Engineering IFIN-HH, 30 Reactorului Street, 077125, Bucharest-Măgurele, Romania
- Faculty of Physics, University of Bucharest, 405 Atomiștilor Street, 050663, Măgurele, Romania
| | - Florin Teleanu
- Biophysics and Biomedical Applications Laboratory and Group, LGED, ELI-NP, "Horia Hulubei" National Institute for Physics and Nuclear Engineering IFIN-HH, 30 Reactorului Street, 077125, Bucharest-Măgurele, Romania
- Interdisciplinary School of Doctoral Studies, University of Bucharest, 36-46 Mihail Kogălniceanu Bd, 050107, Bucharest, Romania
- Department of Chemistry, New York University, 100 Washington Square East, New York, NY, 10003, USA
| | - Andrei Ciumeică
- Interdisciplinary School of Doctoral Studies, University of Bucharest, 36-46 Mihail Kogălniceanu Bd, 050107, Bucharest, Romania
| | - Adonis Lupulescu
- Biophysics and Biomedical Applications Laboratory and Group, LGED, ELI-NP, "Horia Hulubei" National Institute for Physics and Nuclear Engineering IFIN-HH, 30 Reactorului Street, 077125, Bucharest-Măgurele, Romania
| | - Aude Sadet
- Biophysics and Biomedical Applications Laboratory and Group, LGED, ELI-NP, "Horia Hulubei" National Institute for Physics and Nuclear Engineering IFIN-HH, 30 Reactorului Street, 077125, Bucharest-Măgurele, Romania.
- Institute of Biological Chemistry, Faculty of Chemistry, University of Vienna, 1090, Vienna, Austria.
| | - Paul R Vasos
- Biophysics and Biomedical Applications Laboratory and Group, LGED, ELI-NP, "Horia Hulubei" National Institute for Physics and Nuclear Engineering IFIN-HH, 30 Reactorului Street, 077125, Bucharest-Măgurele, Romania.
- Interdisciplinary School of Doctoral Studies, University of Bucharest, 36-46 Mihail Kogălniceanu Bd, 050107, Bucharest, Romania.
- Institute of Biological Chemistry, Faculty of Chemistry, University of Vienna, 1090, Vienna, Austria.
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Teleanu F, Vasos PR. Mechanisms of coherent re-arrangement for long-lived spin order. MAGNETIC RESONANCE (GOTTINGEN, GERMANY) 2021; 2:741-749. [PMID: 37905221 PMCID: PMC10539845 DOI: 10.5194/mr-2-741-2021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 07/30/2021] [Indexed: 11/01/2023]
Abstract
Long-lived spin order-based approaches for magnetic resonance rely on the transition between two magnetic environments of different symmetries, one governed by the magnetic field of the spectrometer and the other where this strong magnetic field is inconsequential. Research on the excitation of magnetic-symmetry transitions in nuclear spins is a scientific field that debuted in Southampton in the year 2000. We advanced in this field carrying the baggage of pre-established directions in NMR spectroscopy. We propose to reveal herein the part of discoveries that may have been obscured by our choice to only look at them through the experience of such pre-established directions at the time. The methodological developments that are emphasised herein are the mechanisms of translation between the symmetric and non-symmetric environments with respect to the main magnetic field B 0 . More specifically, we look again thoroughly at zero-quantum rotations in the starting blocks of long-lived state populations, magnetisation transfers between hyperpolarised heteronuclei, and protons. These pulse sequences seed subsequent magnetic mechanisms that contribute to further applications. For instance, we show how some of the introduced coherence rotations were combined with classical pulse blocks to obtain two-dimensional correlations between protons and heteronuclei. We hope the pulse sequence building blocks discussed herein will open further perspectives for magnetic resonance experiments with long-lived spin order.
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Affiliation(s)
- Florin Teleanu
- Extreme Light Infrastructure Nuclear Physics ELI-NP, Laser Gamma Experiments Department (LGED), Horia Hulubei National Institute for
Physics and Nuclear Engineering IFIN-HH, 30 Reactorului Street, 077125
Bucharest-Măgurele, Romania
- Interdisciplinary School of Doctoral Studies, University of
Bucharest, Blvd. Regina Elisabeta, 030018 Bucharest, Romania
| | - Paul R. Vasos
- Extreme Light Infrastructure Nuclear Physics ELI-NP, Laser Gamma Experiments Department (LGED), Horia Hulubei National Institute for
Physics and Nuclear Engineering IFIN-HH, 30 Reactorului Street, 077125
Bucharest-Măgurele, Romania
- Interdisciplinary School of Doctoral Studies, University of
Bucharest, Blvd. Regina Elisabeta, 030018 Bucharest, Romania
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4
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Teleanu F, Sadet A, Vasos PR. Symmetry versus entropy: Long-lived states and coherences. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2021; 122:63-75. [PMID: 33632418 DOI: 10.1016/j.pnmrs.2020.12.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 09/28/2020] [Accepted: 12/18/2020] [Indexed: 06/12/2023]
Abstract
In recent years, new molecular symmetry-based approaches for magnetic resonance have been invented. The implications of these discoveries will be significant for molecular imaging via magnetic resonance, in vitro as well as in vivo, for quantum computing and for other fields. Since the initial observation in 2004 in Southampton that effective spin symmetry can be instilled in a molecule during magnetic resonance experiments, spin states that are resilient to relaxation mechanisms have been increasingly used. Most of these states are related to the nuclear singlet in a pair of J-coupled spins. Tailored relaxation rate constants for magnetization became available in molecules of different sizes and structures, as experimental developments broadened the scope of symmetry-adapted spin states. The ensuing access to timescales longer than the classically-attained ones by circa one order of magnitude allows the study of processes such as slow diffusion or slow exchange that were previously beyond reach. Long-lived states formed by differences between populations of singlets and triplets have overcome the limitations imposed by longitudinal relaxation times (T1) by factors up to 40. Long-lived coherences formed by superpositions of singlets and triplets have overcome the limit of classical transverse coherence (T2) by a factor 9. We present here an overview of the development and applications of long-lived states (LLS) and long-lived coherences (LLC's) and considerations on future perspectives.
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Affiliation(s)
- Florin Teleanu
- Extreme Light Infrastructure - Nuclear Physics ELI-NP, Laser Gamma Experiments Department (LGED), "Horia Hulubei" National Institute for Physics and Nuclear Engineering IFIN-HH, 30 Reactorului Street, RO-077125 Bucharest-Măgurele, Romania; College for Advanced Performance Studies, Babeș-Bolyai University, Mihail Kogălniceanu Street 1, Cluj-Napoca, Romania; Interdisciplinary School of Doctoral Studies, University of Bucharest, B-dul Regina Elisabeta, Bucharest, Romania
| | - Aude Sadet
- Extreme Light Infrastructure - Nuclear Physics ELI-NP, Laser Gamma Experiments Department (LGED), "Horia Hulubei" National Institute for Physics and Nuclear Engineering IFIN-HH, 30 Reactorului Street, RO-077125 Bucharest-Măgurele, Romania
| | - Paul R Vasos
- Extreme Light Infrastructure - Nuclear Physics ELI-NP, Laser Gamma Experiments Department (LGED), "Horia Hulubei" National Institute for Physics and Nuclear Engineering IFIN-HH, 30 Reactorului Street, RO-077125 Bucharest-Măgurele, Romania; Interdisciplinary School of Doctoral Studies, University of Bucharest, B-dul Regina Elisabeta, Bucharest, Romania.
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Mishra R, Singh M, Singh H, Haridas V, Kurur ND. Revealing Signs and Hidden 1H NMR Coupling Constants in Three-Spin Systems Using Long-Lived Coherences. J Phys Chem Lett 2019; 10:7259-7263. [PMID: 31682452 DOI: 10.1021/acs.jpclett.9b02944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Long-lived coherences (LLCs) in a pair of coupled protons have long lifetimes and hence decreased line width and increased spectral resolution. Fourier transformation of the damped oscillatory decay of the LLC also provides coupling information on the spin system. In a three-spin system, unlike in the two-spin case, the peaks in an LLC spectrum are observed at combinations of the coupling constants. This attribute is used to determine the relative signs of the coupling constants in weakly and strongly coupled model systems. In addition, it is shown that a coupling constant in a three-spin system that is unobservable in the 1H NMR spectrum, as is the case in bispidinone, a molecule of significance in peptidomimetics, may be determined from the LLC spectrum.
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Affiliation(s)
- Rituraj Mishra
- Department of Chemistry , Indian Institute of Technology Delhi , Hauz Khas , New Delhi 110016 , India
| | - Maninder Singh
- Biomedical Imaging Center , Pennington Biomedical Research Center , Baton Rouge , Louisiana 70808 , United States
| | - Hanuman Singh
- Department of Chemistry , Indian Institute of Technology Delhi , Hauz Khas , New Delhi 110016 , India
| | - V Haridas
- Department of Chemistry , Indian Institute of Technology Delhi , Hauz Khas , New Delhi 110016 , India
| | - Narayanan D Kurur
- Department of Chemistry , Indian Institute of Technology Delhi , Hauz Khas , New Delhi 110016 , India
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6
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Sadet A, Stavarache C, Teleanu F, Vasos PR. Water hydrogen uptake in biomolecules detected via nuclear magnetic phosphorescence. Sci Rep 2019; 9:17118. [PMID: 31745146 PMCID: PMC6864387 DOI: 10.1038/s41598-019-53558-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Accepted: 10/16/2019] [Indexed: 11/27/2022] Open
Abstract
We introduce a new symmetry-based method for structural investigations of areas surrounding water-exchanging hydrogens in biomolecules by liquid-state nuclear magnetic resonance spectroscopy. Native structures of peptides and proteins can be solved by NMR with fair resolution, with the notable exception of labile hydrogen sites. The reason why biomolecular structures often remain elusive around exchangeable protons is that the dynamics of their exchange with the solvent hampers the observation of their signals. The new spectroscopic method we report allows to locate water-originating hydrogens in peptides and proteins via their effect on nuclear magnetic transitions similar to electronic phosphorescence, long-lived coherences. The sign of long-lived coherences excited in coupled protons can be switched by the experimenter. The different effect of water-exchanging hydrogens on long-lived coherences with opposed signs allows to pinpoint the position of these labile hydrogen atoms in the molecular framework of peptides and proteins.
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Affiliation(s)
- Aude Sadet
- Research Institute of the University of Bucharest (ICUB), 36-46 B-dul M. Kogalniceanu, RO-050107, Bucharest, Romania.,"Horia Hulubei" National Institute for Physics and Nuclear Engineering IFIN-HH, Extreme Light Infrastructure - Nuclear Physics ELI-NP, 30 Reactorului Street, RO-077125, Bucharest-Magurele, Romania
| | - Cristina Stavarache
- Research Institute of the University of Bucharest (ICUB), 36-46 B-dul M. Kogalniceanu, RO-050107, Bucharest, Romania.,"C. D. Nenitescu" Centre of Organic Chemistry, 202-B Spl. Independentei, RO-060023, Bucharest, Romania
| | - Florin Teleanu
- Research Institute of the University of Bucharest (ICUB), 36-46 B-dul M. Kogalniceanu, RO-050107, Bucharest, Romania.,Faculty of Chemistry and Chemical Engineering, Babes-Bolyai University, Arany Janos 11, Cluj-Napoca, Romania.,"Horia Hulubei" National Institute for Physics and Nuclear Engineering IFIN-HH, Extreme Light Infrastructure - Nuclear Physics ELI-NP, 30 Reactorului Street, RO-077125, Bucharest-Magurele, Romania
| | - Paul R Vasos
- Research Institute of the University of Bucharest (ICUB), 36-46 B-dul M. Kogalniceanu, RO-050107, Bucharest, Romania. .,"Horia Hulubei" National Institute for Physics and Nuclear Engineering IFIN-HH, Extreme Light Infrastructure - Nuclear Physics ELI-NP, 30 Reactorului Street, RO-077125, Bucharest-Magurele, Romania.
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7
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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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8
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Asavei T, Bobeica M, Nastasa V, Manda G, Naftanaila F, Bratu O, Mischianu D, Cernaianu MO, Ghenuche P, Savu D, Stutman D, Tanaka KA, Radu M, Doria D, Vasos PR. Laser-driven radiation: Biomarkers for molecular imaging of high dose-rate effects. Med Phys 2019; 46:e726-e734. [PMID: 31357243 PMCID: PMC6899889 DOI: 10.1002/mp.13741] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 04/11/2019] [Accepted: 07/03/2019] [Indexed: 12/15/2022] Open
Abstract
Recently developed short‐pulsed laser sources garner high dose‐rate beams such as energetic ions and electrons, x rays, and gamma rays. The biological effects of laser‐generated ion beams observed in recent studies are different from those triggered by radiation generated using classical accelerators or sources, and this difference can be used to develop new strategies for cancer radiotherapy. High‐power lasers can now deliver particles in doses of up to several Gy within nanoseconds. The fast interaction of laser‐generated particles with cells alters cell viability via distinct molecular pathways compared to traditional, prolonged radiation exposure. The emerging consensus of recent literature is that the differences are due to the timescales on which reactive molecules are generated and persist, in various forms. Suitable molecular markers have to be adopted to monitor radiation effects, addressing relevant endogenous molecules that are accessible for investigation by noninvasive procedures and enable translation to clinical imaging. High sensitivity has to be attained for imaging molecular biomarkers in cells and in vivo to follow radiation‐induced functional changes. Signal‐enhanced MRI biomarkers enriched with stable magnetic nuclear isotopes can be used to monitor radiation effects, as demonstrated recently by the use of dynamic nuclear polarization (DNP) for biomolecular observations in vivo. In this context, nanoparticles can also be used as radiation enhancers or biomarker carriers. The radiobiology‐relevant features of high dose‐rate secondary radiation generated using high‐power lasers and the importance of noninvasive biomarkers for real‐time monitoring the biological effects of radiation early on during radiation pulse sequences are discussed.
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Affiliation(s)
- Theodor Asavei
- Extreme Light Infrastructure - Nuclear Physics ELI-NP, "Horia Hulubei" National Institute for Physics and Nuclear Engineering, 30 Reactorului Street, RO-077125, Bucharest-Magurele, Romania
| | - Mariana Bobeica
- Extreme Light Infrastructure - Nuclear Physics ELI-NP, "Horia Hulubei" National Institute for Physics and Nuclear Engineering, 30 Reactorului Street, RO-077125, Bucharest-Magurele, Romania
| | - Viorel Nastasa
- Extreme Light Infrastructure - Nuclear Physics ELI-NP, "Horia Hulubei" National Institute for Physics and Nuclear Engineering, 30 Reactorului Street, RO-077125, Bucharest-Magurele, Romania.,National Institute for Laser, Plasma and Radiation Physics, 409 Atomistilor Street, RO-077125, Bucharest-Magurele, Romania
| | - Gina Manda
- Cellular and Molecular Medicine Department, "Victor Babes" National Institute of Pathology, 99-101 Splaiul Independentei, Bucharest, 050096, Romania
| | - Florin Naftanaila
- Carol Davila University of Medicine and Pharmacy Bucharest, Dr Carol Davila Central Mil University Emergency Hospital, 88th Mircea Vulcanescu Str, Bucharest, Romania.,Amethyst Radiotherapy Clinic, Dr Odaii 42, Otopeni, Romania
| | - Ovidiu Bratu
- Carol Davila University of Medicine and Pharmacy Bucharest, Dr Carol Davila Central Mil University Emergency Hospital, 88th Mircea Vulcanescu Str, Bucharest, Romania
| | - Dan Mischianu
- Carol Davila University of Medicine and Pharmacy Bucharest, Dr Carol Davila Central Mil University Emergency Hospital, 88th Mircea Vulcanescu Str, Bucharest, Romania
| | - Mihail O Cernaianu
- Extreme Light Infrastructure - Nuclear Physics ELI-NP, "Horia Hulubei" National Institute for Physics and Nuclear Engineering, 30 Reactorului Street, RO-077125, Bucharest-Magurele, Romania
| | - Petru Ghenuche
- Extreme Light Infrastructure - Nuclear Physics ELI-NP, "Horia Hulubei" National Institute for Physics and Nuclear Engineering, 30 Reactorului Street, RO-077125, Bucharest-Magurele, Romania
| | - Diana Savu
- Department of Life and Environmental Physics, Horia Hulubei" National Institute for Physics and Nuclear Engineering, 30 Reactorului Street, RO-077125, Bucharest-Magurele, Romania
| | - Dan Stutman
- Extreme Light Infrastructure - Nuclear Physics ELI-NP, "Horia Hulubei" National Institute for Physics and Nuclear Engineering, 30 Reactorului Street, RO-077125, Bucharest-Magurele, Romania.,National Institute for Laser, Plasma and Radiation Physics, 409 Atomistilor Street, RO-077125, Bucharest-Magurele, Romania.,Johns Hopkins University, 3400 N Charles St, Baltimore, Maryland, 21218, USA
| | - Kazuo A Tanaka
- Extreme Light Infrastructure - Nuclear Physics ELI-NP, "Horia Hulubei" National Institute for Physics and Nuclear Engineering, 30 Reactorului Street, RO-077125, Bucharest-Magurele, Romania
| | - Mihai Radu
- Department of Life and Environmental Physics, Horia Hulubei" National Institute for Physics and Nuclear Engineering, 30 Reactorului Street, RO-077125, Bucharest-Magurele, Romania
| | - Domenico Doria
- Extreme Light Infrastructure - Nuclear Physics ELI-NP, "Horia Hulubei" National Institute for Physics and Nuclear Engineering, 30 Reactorului Street, RO-077125, Bucharest-Magurele, Romania.,Centre for Plasma Physics, School of Mathematics and Physics, Queen's University Belfast, Belfast, BT7 1NN, United Kingdom
| | - Paul R Vasos
- Extreme Light Infrastructure - Nuclear Physics ELI-NP, "Horia Hulubei" National Institute for Physics and Nuclear Engineering, 30 Reactorului Street, RO-077125, Bucharest-Magurele, Romania.,Research Institute of the University of Bucharest (ICUB), 36-46 B-dul M. Kogalniceanu, RO-050107, Bucharest, Romania
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Stavarache C, Hanganu A, Paun A, Paraschivescu C, Matache M, Vasos PR. Long-lived states detect interactions between small molecules and diamagnetic metal ions. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2017; 284:15-19. [PMID: 28938134 DOI: 10.1016/j.jmr.2017.09.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Revised: 08/25/2017] [Accepted: 09/01/2017] [Indexed: 06/07/2023]
Abstract
Long-lived states of nuclear spin order were used for the first time to probe interactions between molecules and diamagnetic metal ions. Proton spin states with lifetimes twice as long as the spin-lattice relaxation time constants of the same nuclei were promoted on the methoxyphenyl and tolyl substituents of a 1,3,4-oxadiazole derivative. The transient interaction of this oxadiazole derivative with silver(I) ions significantly speeds up the relaxation rate constants of proton long-lived states. The interactions between silver and organic compounds lead to the formation of coordination polymers that can be used for the preparation of bio-compatible materials.
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Affiliation(s)
- Cristina Stavarache
- Institute of Organic Chemistry "C.D. Nenitescu" of the Romanian Academy, 202B Spl. Independentei, 060023 Bucharest, Romania; Department of Organic Chemistry, Biochemistry and Catalysis, Faculty of Chemistry, University of Bucharest, Sos. Panduri, No. 90, 050663 Bucharest, Romania
| | - Anamaria Hanganu
- Institute of Organic Chemistry "C.D. Nenitescu" of the Romanian Academy, 202B Spl. Independentei, 060023 Bucharest, Romania; Department of Organic Chemistry, Biochemistry and Catalysis, Faculty of Chemistry, University of Bucharest, Sos. Panduri, No. 90, 050663 Bucharest, Romania
| | - Anca Paun
- Department of Organic Chemistry, Biochemistry and Catalysis, Faculty of Chemistry, University of Bucharest, Sos. Panduri, No. 90, 050663 Bucharest, Romania
| | - Codruta Paraschivescu
- Department of Organic Chemistry, Biochemistry and Catalysis, Faculty of Chemistry, University of Bucharest, Sos. Panduri, No. 90, 050663 Bucharest, Romania
| | - Mihaela Matache
- Department of Organic Chemistry, Biochemistry and Catalysis, Faculty of Chemistry, University of Bucharest, Sos. Panduri, No. 90, 050663 Bucharest, Romania
| | - Paul R Vasos
- Research Institute of the University of Bucharest (ICUB), 36-46 B-dul M. Kogalniceanu, 050107 Bucharest, Romania; Extreme Light Infrastructure (ELI-NP)/Horia Hulubei National Institute of Physics & Nuclear Engineering (IFIN-HH), Reactorului St., 30, PO Box MG-6, 077125 Bucharest-Magurele, Romania.
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