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Benny J, Saito T, Liu J. Nitrosation mechanisms, kinetics, and dynamics of the guanine and 9-methylguanine radical cations by nitric oxide-Radical-radical combination at different electron configurations. J Chem Phys 2024; 161:125101. [PMID: 39319660 DOI: 10.1063/5.0230367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2024] [Accepted: 09/06/2024] [Indexed: 09/26/2024] Open
Abstract
As a precursor to various reactive nitrogen species formed in biological systems, nitric oxide (•NO) participates in numerous processes, including enhancing DNA radiosensitivity in ionizing radiation-based radiotherapy. Forming guanine radical cations is another common DNA lesion resulting from ionization and oxidation damage. As such, the interaction of •NO with guanine radical cations (G•+) may contribute to the radiosensitization of •NO. An intriguing aspect of this process is the participation of multiple spin configurations in the reaction, including open-shell singlet 1,OS[G•+(↑)⋯(↓)•NO], closed-shell singlet 1,CS[G(↑↓)⋯NO+], and triplet 3[G•+(↑)⋯(↑)•NO]. In this study, the reactions of •NO with both unsubstituted guanine radical cations (in the 9HG•+ conformation) and 9-methylguanine radical cations (9MG•+, a guanosine-mimicking model compound) were investigated in the absence and presence of monohydration of radical cations. Kinetic-energy dependent reaction product ions and cross sections were measured using an electrospray ionization guided-ion beam tandem mass spectrometer. The reaction mechanisms, kinetics, and dynamics were comprehended by interpreting the reaction potential energy surface using spin-projected density functional theory, coupled cluster theory, and multiconfiguration complete active space second-order perturbation theory, followed by RRKM kinetics modeling. The combined experimental and computational findings revealed closed-shell singlet 1,CS[7-NO-9MG]+ as the major, exothermic product and triplet 3[8-NO-9MG]+ as the minor, endothermic product. Singlet biradical products were not detected due to high reaction endothermicities, activation barriers, and inherent instability.
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Affiliation(s)
- Jonathan Benny
- Department of Chemistry and Biochemistry, Queens College of the City University of New York, 65-30 Kissena Blvd., Queens, New York 11367, USA
- The Ph.D. Program in Chemistry, the Graduate Center of the City University of New York, 365 5th Ave., New York, New York 10016, USA
| | - Toru Saito
- Department of Biomedical Information Science, Graduate School of Information Science, Hiroshima City University, 731-3194 Hiroshima, Japan
| | - Jianbo Liu
- Department of Chemistry and Biochemistry, Queens College of the City University of New York, 65-30 Kissena Blvd., Queens, New York 11367, USA
- The Ph.D. Program in Chemistry, the Graduate Center of the City University of New York, 365 5th Ave., New York, New York 10016, USA
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2
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Benny J, Liu J. Spin-orbit charge transfer from guanine and 9-methylguanine radical cations to nitric oxide radicals and the induced triplet-to-singlet intersystem crossing. J Chem Phys 2023; 159:085102. [PMID: 37638623 DOI: 10.1063/5.0160921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Accepted: 08/08/2023] [Indexed: 08/29/2023] Open
Abstract
Nitric oxide (●NO) participates in many biological activities, including enhancing DNA radiosensitivity in ionizing radiation-based radiotherapy. To help understand the radiosensitization of ●NO, we report reaction dynamics between ●NO and the radical cations of guanine (a 9HG●+ conformer) and 9-methylguanine (9MG●+). On the basis of the formation of 9HG●+ and 9MG●+ in the gas phase and the collisions of the radical cations with ●NO in a guided-ion beam mass spectrometer, the charge transfer reactions of 9HG●+ and 9MG●+ with ●NO were examined. For both reactions, the kinetic energy-dependent product ion cross sections revealed a threshold energy that is 0.24 (or 0.37) eV above the 0 K product 9HG (or 9MG) + NO+ asymptote. To interrogate this abnormal threshold behavior, the reaction potential energy surface for [9MG + NO]+ was mapped out at closed-shell singlet, open-shell singlet, and triplet states using density functional and coupled cluster theories. The results showed that the charge transfer reaction requires the interaction of a triplet-state surface originating from a reactant-like precursor complex 3[9MG●+(↑)⋅(↑)●NO] with a closed-shell singlet-state surface evolving from a charge-transferred complex 1[9MG⋅NO+]. During the reaction, an electron is transferred from π∗(NO) to perpendicular π∗(9MG), which introduces a change in orbital angular momentum. The latter offsets the change in electron spin angular momentum and facilitates intersystem crossing. The reaction threshold in excess of the 0 K thermochemistry and the low charge-transfer efficiency are rationalized by the vibrational excitation in the product ion NO+ and the kinetic shift arising from a long-lived triplet intermediate.
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Affiliation(s)
- Jonathan Benny
- Department of Chemistry and Biochemistry, Queens College of the City University of New York, 65-30 Kissena Blvd., Queens, New York 11367, USA
- The Ph.D. Program in Chemistry, The Graduate Center of the City University of New York, 365 5th Ave., New York, New York 10016, USA
| | - Jianbo Liu
- Department of Chemistry and Biochemistry, Queens College of the City University of New York, 65-30 Kissena Blvd., Queens, New York 11367, USA
- The Ph.D. Program in Chemistry, The Graduate Center of the City University of New York, 365 5th Ave., New York, New York 10016, USA
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3
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Zima V, Vlk M, Wan J, Cvačka J, Tureček F. Tracking Isomerizations of High-Energy Adenine Cation Radicals by UV-Vis Action Spectroscopy and Cyclic Ion Mobility Mass Spectrometry. J Phys Chem A 2023. [PMID: 37433135 DOI: 10.1021/acs.jpca.3c03179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/13/2023]
Abstract
We report experimental and computational studies of protonated adenine C-8 σ-radicals that are presumed yet elusive reactive intermediates of oxidative damage to nucleic acids. The radicals were generated in the gas phase by the collision-induced dissociation of C-8-Br and C-8-I bonds in protonated 8-bromo- and 8-iodoadenine as well as by 8-bromo- and 8-iodo-9-methyladenine. Protonation by electrospray of 8-bromo- and 8-iodoadenine was shown by cyclic-ion mobility mass spectrometry (c-IMS) to form the N-1-H, N-9-H and N-3-H, N-7-H protomers in 85:15 and 81:19 ratios, respectively, in accordance with the equilibrium populations of these protomers in water-solvated ions that were calculated by density functional theory (DFT). Protonation of 8-halogenated 9-methyladenines yielded single N-1-H protomers, which was consistent with their thermodynamic stability. The radicals produced from the 8-bromo and 8-iodo adenine cations were characterized by UV-vis photodissociation action spectroscopy (UVPD) and c-IMS. UVPD revealed the formation of C-8 σ-radicals along with N-3-H, N-7-H-adenine π-radicals that arose as secondary products by hydrogen atom migrations. The isomers were identified by matching their action spectra against the calculated vibronic absorption spectra. Deuterium isotope effects were found to slow the isomerization and increase the population of C-8 σ-radicals. The adenine cation radicals were separated by c-IMS and identified by their collision cross sections, which were measured relative to the canonical N-9-H adenine cation radical that was cogenerated in situ as an internal standard. Ab initio CCSD(T)/CBS calculations of isomer energies showed that the adenine C-8 σ-radicals were local energy minima with relative energies at 76-79 kJ mol-1 above that of the canonical adenine cation radical. Rice-Ramsperger-Kassel-Marcus calculations of unimolecular rate constants for hydrogen and deuterium migrations resulting in exergonic isomerizations showed kinetic shifts of 10-17 kJ mol-1, stabilizing the C-8 σ-radicals. C-8 σ-radicals derived from N-1-protonated 9-methyladenine were also thermodynamically unstable and readily isomerized upon formation.
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Affiliation(s)
- Václav Zima
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, United States
| | - Mikuláš Vlk
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, 16610 Prague 6, Czech Republic
- Department of Analytical Chemistry, Faculty of Science, Charles University, 12800 Prague, Czech Republic
| | - Jiahao Wan
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, United States
| | - Josef Cvačka
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, 16610 Prague 6, Czech Republic
- Department of Analytical Chemistry, Faculty of Science, Charles University, 12800 Prague, Czech Republic
| | - František Tureček
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, United States
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Wan J, Brož B, Liu Y, Huang SR, Marek A, Tureček F. The DNA Radical Code. Resolution of Identity in Dissociations of Trinucleotide Codon Cation Radicals in the Gas Phase. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2023; 34:304-319. [PMID: 36596259 DOI: 10.1021/jasms.2c00322] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Sixty DNA trinucleotide cation radicals covering a large part of the genetic code alphabet were generated by electron transfer in the gas phase, and their chemistry was studied by collision-induced dissociation tandem mass spectrometry and theoretical calculations. The major dissociations involved loss of nucleobase molecules and radicals, backbone cleavage, and cross-ring fragmentations that depended on the nature and position of the nucleobases. Mass identity in dissociations of symmetrical trinucleotide cation radicals of the (XXX+2H)+• and (XYX+2H)+• type was resolved by specific 15N labeling. The specific features of trinucleotide cation radical dissociations involved the dominant formation of d2+ ions, hydrogen atom migrations accompanying the formation of (w2+H)+•, (w2+2H)+, and (d2+2H)+ sequence ions, and cross-ring cleavages in the 3'- and 5'-deoxyribose moieties that depended on the nucleobase type and its position in the ion. Born-Oppenheimer molecular dynamics (BOMD) and density functional theory calculations were used to obtain structures and energies of several cation-radical protomers and conformers for (AAA+2H)+•, (CCC+2H)+•, (GGG+2H)+•, (ACA+2H)+•, and (CAA+2H)+• that were representative of the different types of backbone dissociations. The ion electronic structure, protonation and radical sites, and hydrogen bonding were used to propose reaction mechanisms for the dissociations.
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Affiliation(s)
- Jiahao Wan
- Department of Chemistry, Bagley Hall, Box 351700, University of Washington, Seattle, Washington 98195-1700, United States
| | - Břetislav Brož
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, 16610 Prague 6, Czech Republic
| | - Yue Liu
- Department of Chemistry, Bagley Hall, Box 351700, University of Washington, Seattle, Washington 98195-1700, United States
| | - Shu R Huang
- Department of Chemistry, Bagley Hall, Box 351700, University of Washington, Seattle, Washington 98195-1700, United States
| | - Aleš Marek
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, 16610 Prague 6, Czech Republic
| | - František Tureček
- Department of Chemistry, Bagley Hall, Box 351700, University of Washington, Seattle, Washington 98195-1700, United States
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5
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Tureček F. UV-vis spectroscopy of gas-phase ions. MASS SPECTROMETRY REVIEWS 2023; 42:206-226. [PMID: 34392556 DOI: 10.1002/mas.21726] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 06/07/2021] [Accepted: 06/08/2021] [Indexed: 06/13/2023]
Abstract
Photodissociation action spectroscopy has made a great progress in expanding investigations of gas-phase ion structures. This review deals with aspects of gas-phase ion electronic excitations that result in wavelength-dependent dissociation and light emission via fluorescence, chiefly covering the ultraviolet and visible regions of the spectrum. The principles are briefly outlined and a few examples of instrumentation are presented. The main thrust of the review is to collect and selectively present applications of UV-vis action spectroscopy to studies of stable gas-phase ion structures and combinations of spectroscopy with ion mobility, collision-induced dissociation, and ion-ion reactions leading to the generation of reactive intermediates and electronic energy transfer.
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Affiliation(s)
- František Tureček
- Department of Chemistry, University of Washington, Seattle, Washington, USA
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6
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Stochastic dynamic quantitative and 3D structural matrix assisted laser desorption/ionization mass spectrometric analyses of mixture of nucleosides. J Mol Struct 2022. [DOI: 10.1016/j.molstruc.2022.132701] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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7
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Zima V, Liu Y, Tureček F. Radical Cascade Dissociation Pathways to Unusual Nucleobase Cation Radicals. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2022; 33:1038-1047. [PMID: 35536606 DOI: 10.1021/jasms.2c00098] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
We report unusual dissociations of protonated RNA nucleosides tagged with radical initiator groups at ribose 5'-O and furnished with a 2',3'-O-isopropylidene protecting group. The ions undergo collision-induced radical cascade dissociations starting at the radical initiator that break down the dioxolane ring and trigger the formation of nucleobase cations and cation radicals. The adenine cation radical that was formed by radical cascade dissociations was identified by MS5 UV-vis photodissociation action spectroscopy to be a higher-energy N-3-H tautomer of the canonical ionized nucleobase. The guanine cation radical was formed by radical cascade dissociations as the N-7-H tautomer. In contrast to adenosine and guanosine, radical cascade dissociations of the tagged ribocytidine ion produced protonated cytosine, whereas tagged ribothymidine showed yet different dissociations resulting in predominant thymine loss. Reaction mechanisms were suggested for the cascade dissociations that were based on Born-Oppenheimer molecular dynamics and density functional theory calculations that were used to map the relevant parts of the potential energy surfaces for adenosine, guanosine, and cytidine radical ions. The reported radical cascade dissociations represent a new, nonredox approach to nucleobase and nucleoside cation radicals that has the potential of being expanded to the generation of various oligonucleotide cation radicals.
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Affiliation(s)
- Václav Zima
- Department of Chemistry, Bagley Hall, Box 351700, University of Washington, Seattle, Washington 981195-1700, United States
| | - Yue Liu
- Department of Chemistry, Bagley Hall, Box 351700, University of Washington, Seattle, Washington 981195-1700, United States
| | - František Tureček
- Department of Chemistry, Bagley Hall, Box 351700, University of Washington, Seattle, Washington 981195-1700, United States
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8
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Huang SR, Tureček F. Noncanonical Isomers of Nucleoside Cation Radicals: An Ab Initio Study of the Dark Matter of DNA Ionization. J Phys Chem A 2022; 126:2480-2497. [PMID: 35439003 DOI: 10.1021/acs.jpca.2c00894] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Cation radicals of DNA nucleosides, 2'-deoxyadenosine, 2'-deoxyguanosine, 2'-deoxycytidine, and 2'-deoxythymidine, can exist in standard canonical forms or as noncanonical isomers in which the charge is introduced by protonation of the nucleobase, whereas the radical predominantly resides in the deoxyribose moiety. Density functional theory as well as correlated ab initio calculations with coupled clusters (CCSD(T)) that were extrapolated to the complete basis set limit showed that noncanonical nucleoside ion isomers were thermodynamically more stable than their canonical forms in both the gas phase and as water-solvated ions. This indicated the possibility of exothermic conversion of canonical to noncanonical forms. The noncanonical isomers were calculated to have very low adiabatic ion-electron recombination energies (REad) for the lowest-energy isomers 2'-deoxy-(N-3H)adenos-1'-yl (4.74 eV), 2'-deoxy-(N-7H)guanos-1'-yl (4.66 eV), 2'-deoxy-(N-3H)cytid-1'-yl (5.12 eV), and 2'-deoxy-5-methylene-(O-2H)uridine (5.24 eV). These were substantially lower than the REad value calculated for the canonical 2'-deoxyadenosine, 2'-deoxy guanosine, 2'-deoxy cytidine, and 2'-deoxy thymidine cation radicals, which were 7.82, 7.46, 8.14, and 8.20 eV, respectively, for the lowest-energy ion conformers of each type. Charge and spin distributions in noncovalent cation-radical dA⊂dT and dG⊂dC nucleoside pairs and dAT, dCT, dTC, and dGC dinucleotides were analyzed to elucidate the electronic structure of the cation radicals. Born-Oppenheimer molecular dynamics trajectory calculations of the dinucleotides and nucleoside pairs indicated rapid exothermic proton transfer from noncanonical T+· to A in both dAT+· and dA⊂dT+·, leading to charge and radical separation. Noncanonical T+· in dCT+· and dTC+· initiated rapid proton transfer to cytosine, whereas the canonical dCT+· dinucleotide ion retained the cation radical structure without isomerization. No spontaneous proton transfer was found in dGC+· and dG⊂dC+· containing canonical neutral and noncanonical ionized deoxycytidine.
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Affiliation(s)
- Shu R Huang
- Department of Chemistry, University of Washington, Bagley Hall, Box 351700, Seattle, Washington 98195-1700, United States
| | - František Tureček
- Department of Chemistry, University of Washington, Bagley Hall, Box 351700, Seattle, Washington 98195-1700, United States
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9
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Marlton SJP, Trevitt A. Laser Photodissocation, Action Spectroscopy and Mass Spectrometry Unite to Detect and Separate Isomers. Chem Commun (Camb) 2022; 58:9451-9467. [DOI: 10.1039/d2cc02101c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The separation and detection of isomers remains a challenge for many areas of mass spectrometry. This article highlights laser photodissociation and ion mobility strategies that have been deployed to tackle...
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10
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Heldmaier FV, Coughlan NJA, Haack A, Huard R, Guna M, Schneider BB, Le Blanc JCY, Campbell JL, Nooijen M, Hopkins WS. UVPD spectroscopy of differential mobility-selected prototropic isomers of protonated adenine. Phys Chem Chem Phys 2021; 23:19892-19900. [PMID: 34525152 DOI: 10.1039/d1cp02688g] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Two prototropic isomers of adenine are formed in an electrospray ion source and are resolved spatially in a differential mobility spectrometer before detection in a triple quadrupole mass spectrometer. Each isomer is gated in CV space before being trapped in the linear ion trap of the modified mass spectrometer, where they are irradiated by the tuneable output of an optical parametric oscillator and undergo photodissociation to form charged fragments with m/z 119, 109, and 94. The photon-normalised intensity of each fragmentation channel is measured and the action spectra for each DMS-gated tautomer are obtained. Our analysis of the action spectra, aided by calculated vibronic spectra and thermochemical data, allow us to assign the two signals in our measured ionograms to specific tautomers of protonated adenine.
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Affiliation(s)
- Fiorella Villanueva Heldmaier
- Department of Chemistry, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, N2L 3G1, Canada. .,Waterloo Institute for Nanotechnology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, N2L 3G1, Canada
| | - Neville J A Coughlan
- Department of Chemistry, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, N2L 3G1, Canada. .,Waterloo Institute for Nanotechnology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, N2L 3G1, Canada
| | - Alexander Haack
- Department of Chemistry, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, N2L 3G1, Canada. .,Waterloo Institute for Nanotechnology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, N2L 3G1, Canada
| | - Rebecca Huard
- Department of Chemistry, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, N2L 3G1, Canada. .,Waterloo Institute for Nanotechnology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, N2L 3G1, Canada
| | - Mircea Guna
- SCIEX, Four Valley Drive, Concord, Ontario, L4K 4V8, Canada
| | | | | | - J Larry Campbell
- Department of Chemistry, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, N2L 3G1, Canada. .,Bedrock Scientific Inc., Milton, Ontario, Canada
| | - Marcel Nooijen
- Department of Chemistry, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, N2L 3G1, Canada.
| | - W Scott Hopkins
- Department of Chemistry, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, N2L 3G1, Canada. .,Waterloo Institute for Nanotechnology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, N2L 3G1, Canada.,Centre for Eye and Vision Research, Hong Kong Science Park, New Territories, Hong Kong.,Watermine Innovation, Waterloo, Ontario, Canada
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11
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Tureček F. Flying DNA Cation Radicals in the Gas Phase: Generation and Action Spectroscopy of Canonical and Noncanonical Nucleobase Forms. J Phys Chem B 2021; 125:7090-7100. [PMID: 34166596 DOI: 10.1021/acs.jpcb.1c03674] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Gas-phase chemistry of cation radicals related to ionized nucleic acids has enjoyed significant recent progress thanks to the development of new methods for cation radical generation, ion spectroscopy, and reactivity studies. Oxidative methods based on intramolecular electron transfer in transition-metal complexes have been used to generate nucleobase and nucleoside cation radicals. Reductive methods relying on intermolecular electron transfer in gas-phase ion-ion reactions have been utilized to generate a number of di- and tetranucleotide cation radicals, as well as charge-tagged nucleoside radicals. The generated cation radicals have been studied by infrared and UV-visible action spectroscopy and ab initio and density functional theory calculations, providing optimized structures, harmonic frequencies, and excited-state analysis. This has led to the discovery of stable noncanonical nucleobase cation radicals of unusual electronic properties and extremely low ion-electron recombination energies. Intramolecular proton-transfer reactions in cation radical oligonucleotides and Watson-Crick nucleoside pairs have been studied experimentally, and their mechanisms have been elucidated by theory. Whereas the range of applications of the oxidative methods is currently limited to nucleobases and readily oxidizable guanosine, the reductive methods can be scaled up to generate large oligonucleotide cation radicals including double-strand DNA. Challenges in the experimental and computational approach to DNA cation radicals are discussed.
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Affiliation(s)
- František Tureček
- Department of Chemistry, Bagley Hall, Box 351700, University of Washington, Seattle, Washington 98195-1700, United States
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12
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Zhang K, Shi Y, Du M, Xu Y, Wang Y, Kong X. Versatile Double-Beam Confocal Laser System Combined with a Fourier Transform Ion Cyclotron Resonance Mass Spectrometer for Photodissociation Mass Spectrometry and Spectroscopy. Anal Chem 2021; 93:9056-9063. [PMID: 34165954 DOI: 10.1021/acs.analchem.1c00248] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Both infrared multiphoton dissociation (IRMPD) and ultraviolet photodissociation (UVPD) play important roles in tandem mass spectrometry and the action spectroscopy of organic and biological molecules. A flexible combination of the two methods may provide researchers with more versatile and powerful ion activation/dissociation choices for structural characterization and spectroscopic studies. Here, we report the integration of two tunable lasers with a Fourier transform ion cyclotron resonance mass spectrometer in a confocal mode, which offers multiple capabilities for photon activation/dissociation experiments. The two overlapped beams can be introduced into the cell individually, sequentially, or simultaneously, providing highly flexible and diverse activation schemes. The setup can also measure the UVPD or IRMPD action spectra of fragment ions generated by previous photon dissociation processes. In addition, the multistage tandem-in-time mass spectrometry performance up to MS4, including three different activation methods in a single cell, has also been demonstrated.
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Affiliation(s)
- Kailin Zhang
- State Key Laboratory of Elemento-organic Chemistry, Collage of Chemistry, Nankai University, Tianjin 300071, China.,School of Precision Instrument and Opto-Electronics Engineering, Tianjin University, Tianjin 300072, China
| | - Yingying Shi
- State Key Laboratory of Elemento-organic Chemistry, Collage of Chemistry, Nankai University, Tianjin 300071, China
| | - Mengying Du
- State Key Laboratory of Elemento-organic Chemistry, Collage of Chemistry, Nankai University, Tianjin 300071, China
| | - Yicheng Xu
- State Key Laboratory of Elemento-organic Chemistry, Collage of Chemistry, Nankai University, Tianjin 300071, China
| | - Yan Wang
- School of Precision Instrument and Opto-Electronics Engineering, Tianjin University, Tianjin 300072, China
| | - Xianglei Kong
- State Key Laboratory of Elemento-organic Chemistry, Collage of Chemistry, Nankai University, Tianjin 300071, China.,Collaborative Innovation Center of Chemical Science and Engineering, Nankai University, Tianjin 300071, China
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13
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Huang SR, Tureček F. Cation Radicals of Hachimoji Nucleobases P and Z: Generation in the Gas Phase and Characterization by UV-Vis Photodissociation Action Spectroscopy and Theory. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2021; 32:373-386. [PMID: 33206519 DOI: 10.1021/jasms.0c00381] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
We report the generation of gas-phase cation radicals of unusual nucleobases 5-aza-7-deazaguanine (P) and 6-amino-5-nitro-(1H)pyrid-2-one (Z) that have been used as building blocks of base-expanded (hachimoji) DNA. The cation radicals were generated by collision-induced intramolecular electron transfer and dissociation of ternary copper-terpyridine complexes. The cation radicals were characterized by deuterium labeling and tandem mass spectrometry including MS3 collision-induced dissociation, UV-vis photodissociation, and action spectroscopy. Vibronic absorption UV-vis spectra were calculated by time-dependent density functional theory (TD-DFT) and compared with the action spectra to unequivocally assign the most closely matching structures for the gas-phase cation radicals. Ab initio calculations up to the coupled clusters-complete basis set (CCSD(T)/CBS) level of theory were used to rank by energy the P and Z neutral molecules and cation-radical isomers and provided transition-state and dissociation energies. The 5-aza-7-deazaguanine cation radicals were determined to have the canonical N-1-H, 6-oxo structure (P1+•) that was the global energy minimum within this group of isomers. The Z cation radicals were found to have the 1H-pyrid-2-one structure (Z1+•). The formation of P1+• and Z1+• was shown to be controlled by the solution thermodynamics of the Cu-terpyridine complexes and the kinetics of their dissociations. We also report and compare CCSD(T)/CBS-calculated adiabatic recombination energies of cation radicals for the entire hachimoji set of eight nucleobases, P+• (7.92 eV), Z+• (8.51 eV), S+• (8.51 eV), B+• (7.76 eV), T+• (8.98 eV), C+• (8.62 eV), A+• (8.32 eV), and G+• (7.97 eV), to assess the thermodynamics of base-to-base electron transfer following random ionization.
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Affiliation(s)
- Shu R Huang
- Department of Chemistry, University of Washington, Bagley Hall, Box 351700, Seattle, Washington 98195-1700, United States
| | - František Tureček
- Department of Chemistry, University of Washington, Bagley Hall, Box 351700, Seattle, Washington 98195-1700, United States
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14
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Van Trang N, Thuy PT, Mai Thanh DT, Son NT. Benzofuran–stilbene hybrid compounds: an antioxidant assessment – a DFT study. RSC Adv 2021. [DOI: 10.1039/d1ra01076j] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The kinetic reaction of the benzofuran–stilbene hybrid compound 5-(2-(2-(4-hydroxyphenyl)benzofuran-5-yl)vinyl)benzene-1,3-diol captures the HOO˙ free radical.
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Affiliation(s)
| | - Phan Thi Thuy
- School of Natural Sciences Education
- Vinh University
- Vietnam
| | - Dinh Thi Mai Thanh
- University of Science and Technology of Hanoi
- Vietnam Academy of Science and Technology (VAST)
- Hanoi
- Vietnam
| | - Ninh The Son
- Institute of Chemistry
- Vietnam Academy of Science and Technology (VAST)
- Hanoi
- Vietnam
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15
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Huang SR, Nováková G, Marek A, Tureček F. The Elusive Noncanonical Isomers of Ionized 9-Methyladenine and 2′-Deoxyadenosine. J Phys Chem A 2020; 125:338-348. [DOI: 10.1021/acs.jpca.0c10293] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Shu R. Huang
- Department of Chemistry, University of Washington, Bagley Hall, Box 351700, Seattle, Washington 98195-1700, United States
| | - Gabriela Nováková
- Institute of Organic Chemistry and Biochemistry, The Czech Academy of Sciences, Flemingovo nám. 2, 16610 Prague 6, Czech Republic
| | - Aleš Marek
- Institute of Organic Chemistry and Biochemistry, The Czech Academy of Sciences, Flemingovo nám. 2, 16610 Prague 6, Czech Republic
| | - František Tureček
- Department of Chemistry, University of Washington, Bagley Hall, Box 351700, Seattle, Washington 98195-1700, United States
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16
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Huang SR, Tureček F. Cation Radicals of Hachimoji Nucleobases. Canonical Purine and Noncanonical Pyrimidine Forms Generated in the Gas Phase and Characterized by UV–Vis Photodissociation Action Spectroscopy. J Phys Chem A 2020; 124:7101-7112. [DOI: 10.1021/acs.jpca.0c06227] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Shu R. Huang
- Department of Chemistry, University of Washington, Bagley Hall, Box 351700, Seattle, Washington 98195-1700, United States
| | - František Tureček
- Department of Chemistry, University of Washington, Bagley Hall, Box 351700, Seattle, Washington 98195-1700, United States
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17
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Zhang K, Ma L, Zhou M, Shi Y, Li S, Wang Y, Kong X. Wavelength-Dependent Ultraviolet Photodissociation of Protonated Tryptamine. J Phys Chem A 2020; 124:5280-5287. [PMID: 32536155 DOI: 10.1021/acs.jpca.0c02528] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Ultraviolet photodissociation (UVPD) experiments of protonated tryptamine ([Tryp+H]+) have been implemented by a Fourier transform ion cyclotron resonance (FTICR) mass spectrometer combined with a wavelength-tunable optical parametric oscillator (OPO) laser. UVPD mass spectra under different laser wavelengths have been obtained, in which the dependence of the yield of fragment ions on the laser wavelength was observed. The UVPD spectrum of [Tryp+H]+ has been obtained in the range of 210-310 nm. Besides the previously reported two competitive channels of H loss and NH3 loss, two important channels of losing CH2NH and CH2NH2 units were observed and further studied by UV-UV tandem mass spectrometry and theoretical calculations. Interestingly, results show that the pair of competitive channels of CH2NH loss and CH2NH2 loss are both from the McLafferty-type rearrangement caused by ππ* electronic excited states. After the excitation, the two different dissociation pathways produce two different ion-neutral complexes, respectively. The wavelength-dependent dissociation and the existing competitive channels shown in this study reflect the diversity of UVPD processes of such organic molecules.
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Affiliation(s)
- Kailin Zhang
- School of Precision Instrument and Opto-Electronics Engineering, Tianjin University, Tianjin 300072, China.,State Key Laboratory and Institute of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, China
| | - Lifu Ma
- School of Precision Instrument and Opto-Electronics Engineering, Tianjin University, Tianjin 300072, China
| | - Min Zhou
- State Key Laboratory and Institute of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, China.,Department of Physics, Anhui Normal University, Wuhu 241000, China
| | - Yingying Shi
- State Key Laboratory and Institute of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, China
| | - Shuqi Li
- State Key Laboratory and Institute of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, China
| | - Yan Wang
- School of Precision Instrument and Opto-Electronics Engineering, Tianjin University, Tianjin 300072, China
| | - Xianglei Kong
- State Key Laboratory and Institute of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, China.,Collaborative Innovation Center of Chemical Science and Engineering, Nankai University, Tianjin 300071, China
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18
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Huang SR, Dang A, Tureček F. Ground and Excited States of Gas-Phase DNA Nucleobase Cation-Radicals. A UV-vis Photodisociation Action Spectroscopy and Computational Study of Adenine and 9-Methyladenine. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2020; 31:1271-1281. [PMID: 32324398 DOI: 10.1021/jasms.0c00095] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Cation radicals of adenine (A•+) and 9-methyladenine (MA•+) were generated in the gas phase by collision-induced intramolecular electron transfer in copper-terpyridine-nucleobase ternary complexes and characterized by collision-induced dissociation (CID) mass spectra and UV-vis photodissociation action spectroscopy in the 210-700 nm wavelength region. The action spectra of both A•+ and MA•+ displayed characteristic absorption bands in the near-UV and visible regions. Another tautomer of A•+ was generated as a minor product by multistep CID of protonated 9-(2-bromoethyl)adenine. Structure analysis by density functional theory and coupled-clusters ab initio calculations pointed to the canonical 9-H-tautomer Ad1•+ as the global energy minimum of adenine cation radicals. The canonical tautomer MA1•+ was also calculated to be a low-energy structure among methyladenine cation radicals. However, two new noncanonical tautomers were found to be energetically comparable to MA1•+. Vibronic absorption spectra were calculated for several tautomers of A•+ and MA•+ and benchmarked on equation-of-motion coupled-clusters excited-state calculations. Analysis of the vibronic absorption spectra of A•+ tautomers pointed to the canonical tautomer Ad1•+ as providing the best match with the action spectrum. Likewise, the canonical tautomer MA1•+ was the unequivocal best match for the MA•+ ion generated in the gas phase. According to potential-energy mapping, MA1•+ was separated from energetically favorable noncanonical cation radicals by a high-energy barrier that was calculated to be above the dissociation threshold for loss of a methyl hydrogen atom, thus preventing isomerization. Structures and energetics of all four DNA nucleobase cation radicals are compared and discussed.
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Affiliation(s)
- Shu R Huang
- Department of Chemistry, University of Washington, Bagley Hall, Box 351700, Seattle, Washington 98195-1700, United States
| | - Andy Dang
- Department of Chemistry, University of Washington, Bagley Hall, Box 351700, Seattle, Washington 98195-1700, United States
| | - František Tureček
- Department of Chemistry, University of Washington, Bagley Hall, Box 351700, Seattle, Washington 98195-1700, United States
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19
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Liu Y, Dang A, Urban J, Tureček F. Charge‐Tagged DNA Radicals in the Gas Phase Characterized by UV/Vis Photodissociation Action Spectroscopy. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.201916493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Yue Liu
- Department of Chemistry University of Washington Seattle WA 98195-1700 USA
| | - Andy Dang
- Department of Chemistry University of Washington Seattle WA 98195-1700 USA
| | - Jan Urban
- Metagenics, Inc. Gig Harbor WA 98332 USA
| | - František Tureček
- Department of Chemistry University of Washington Seattle WA 98195-1700 USA
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20
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Huang SR, Liu Y, Tureček F. UV–vis Photodissociation Action Spectroscopy Reveals Cytosine–Guanine Hydrogen Transfer in DNA Tetranucleotide Cation Radicals upon One-Electron Reduction. J Phys Chem B 2020; 124:3505-3517. [DOI: 10.1021/acs.jpcb.0c01693] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Shu R. Huang
- Department of Chemistry, Bagley Hall, Box
351700, University of Washington, Seattle, Washington 98195-1700, United States
| | - Yue Liu
- Department of Chemistry, Bagley Hall, Box
351700, University of Washington, Seattle, Washington 98195-1700, United States
| | - František Tureček
- Department of Chemistry, Bagley Hall, Box
351700, University of Washington, Seattle, Washington 98195-1700, United States
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21
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Liu Y, Dang A, Urban J, Tureček F. Charge‐Tagged DNA Radicals in the Gas Phase Characterized by UV/Vis Photodissociation Action Spectroscopy. Angew Chem Int Ed Engl 2020; 59:7772-7777. [DOI: 10.1002/anie.201916493] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 01/22/2020] [Indexed: 11/05/2022]
Affiliation(s)
- Yue Liu
- Department of Chemistry University of Washington Seattle WA 98195-1700 USA
| | - Andy Dang
- Department of Chemistry University of Washington Seattle WA 98195-1700 USA
| | - Jan Urban
- Metagenics, Inc. Gig Harbor WA 98332 USA
| | - František Tureček
- Department of Chemistry University of Washington Seattle WA 98195-1700 USA
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22
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Liu Y, Huang SR, Tureček F. Guanine–adenine interactions in DNA tetranucleotide cation radicals revealed by UV/vis photodissociation action spectroscopy and theory. Phys Chem Chem Phys 2020; 22:16831-16842. [DOI: 10.1039/d0cp02362k] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Hydrogen-rich cation radicals (GATT + 2H)+˙ and (AGTT + 2H)+˙ represent oligonucleotide models of charged hydrogen atom adducts to DNA.
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Affiliation(s)
- Yue Liu
- Department of Chemistry
- University of Washington
- Seattle
- USA
| | - Shu R. Huang
- Department of Chemistry
- University of Washington
- Seattle
- USA
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23
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Dang A, Korn JA, Gladden J, Mozzone B, Tureček F. UV-Vis Photodissociation Action Spectroscopy on Thermo LTQ-XL ETD and Bruker amaZon Ion Trap Mass Spectrometers: a Practical Guide. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2019; 30:1558-1564. [PMID: 31087269 DOI: 10.1007/s13361-019-02229-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 04/09/2019] [Accepted: 04/13/2019] [Indexed: 06/09/2023]
Abstract
We report automated procedures for multiple tandem mass spectra acquisition allowing UV-Vis photodissociation action spectroscopy measurements of ions and radicals. The procedures were developed for two commercial ion trap mass spectrometers and applied to collision-induced and electron-transfer dissociation tandem mass spectrometry modes of ion generation.
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Affiliation(s)
- Andy Dang
- Department of Chemistry, University of Washington, Bagley Hall, Box 351700, Seattle, WA, 98195-1700, USA
| | - Joseph A Korn
- Department of Chemistry, University of Washington, Bagley Hall, Box 351700, Seattle, WA, 98195-1700, USA
| | - James Gladden
- Department of Chemistry, University of Washington, Bagley Hall, Box 351700, Seattle, WA, 98195-1700, USA
| | - Brandon Mozzone
- Department of Chemistry, University of Washington, Bagley Hall, Box 351700, Seattle, WA, 98195-1700, USA
| | - František Tureček
- Department of Chemistry, University of Washington, Bagley Hall, Box 351700, Seattle, WA, 98195-1700, USA.
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24
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Karton A. Thermochemistry of Guanine Tautomers Re-Examined by Means of High-Level CCSD(T) Composite Ab Initio Methods. Aust J Chem 2019. [DOI: 10.1071/ch19276] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
We obtained accurate gas-phase tautomerization energies for a set of 14 guanine tautomers by means of high-level thermochemical procedures approximating the CCSD(T) energy at the complete basis set (CBS) limit. For the five low-lying tautomers, we use the computationally demanding W1-F12 composite method for obtaining the tautomerization energies. The relative W1-F12 tautomerization enthalpies at 298K are: 0.00 (1), 2.37 (2), 2.63 (3), 4.03 (3′), and 14.31 (4) kJmol−1. Thus, as many as four tautomers are found within a small energy window of less than 1.0kcalmol−1 (1kcalmol−1=4.184kJmol−1). We use these highly accurate W1-F12 tautomerization energies to evaluate the performance of a wide range of lower-level composite ab initio procedures. The Gn composite procedures (G4, G4(MP2), G4(MP2)-6X, G3, G3B3, G3(MP2), and G3(MP2)B3) predict that the enol tautomer (3) is more stable than the keto tautomer (2) by amounts ranging from 0.36 (G4) to 1.28 (G3(MP2)) kJmol−1. We also find that an approximated CCSD(T)/CBS energy calculated as HF/jul-cc-pV{D,T}Z+CCSD/jul-cc-pVTZ+(T)/jul-cc-pVDZ results in a root-mean-square deviation (RMSD) of merely 0.11kJmol−1 relative to the W1-F12 reference values. We use this approximated CCSD(T)/CBS method to obtain the tautomerization energies of 14 guanine tautomers. The relative tautomerization enthalpies at 298K are: 0.00 (1), 2.20 (2), 2.51 (3), 4.06 (3′), 14.30 (4), 25.65 (5), 43.78 (4′), 53.50 (6′), 61.58 (6), 77.37 (7), 82.52 (8′), 86.02 (9), 100.70 (10), and 121.01 (8) kJmol−1. Using these tautomerization enthalpies, we evaluate the performance of standard and composite methods for the entire set of 14 guanine tautomers. The best-performing procedures emerge as (RMSDs are given in parentheses): G4(MP2)-6X (0.51), CCSD(T)+ΔMP2/CBS (0.52), and G4(MP2) (0.64kJmol−1). The worst performers are CCSD(T)/AVDZ (1.05), CBS-QB3 (1.24), and CBS-APNO (1.38kJmol−1).
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