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Cui X, Fan J, Lyu Y, Zhou X, Meng Q, Zhang C. Quasi-intrinsic thiobase derivatives as potential targeted photosensitizers in two-photon photodynamic therapy. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2024; 316:124311. [PMID: 38663131 DOI: 10.1016/j.saa.2024.124311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2024] [Revised: 04/08/2024] [Accepted: 04/17/2024] [Indexed: 05/15/2024]
Abstract
In this study, a set of potential quasi-intrinsic photosensitizers for two-photon photodynamic therapy (PDT) are proposed based on the unnatural 2-amino-8-(1'-β-ᴅ-2'-deoxyribofuranosyl)-imidazo[1,2-ɑ]-1,3,5-triazin-4(8H)-one (P), which is paired with the 6-amino-5-nitro-3-(1'-β-ᴅ-2'-deoxyribofuranosyl)-2(1H)-pyridone (Z) and can specifically recognize breast and liver cancer cells. Herein, the effects of sulfur substitution and electron-donating/electron-withdrawing groups on the photophysical properties in aqueous solution are systematically investigated. The one- and two-photon absorption spectra evidence that the modifications could result in red-shifted absorption wavelength and large two-photon absorption cross-section, which contributes to selective excitation and provides effective PDT for deep-seated tissues. To ensure the efficient triplet state population, the singlet-triplet energy gaps and spin-orbit coupling constants were examined, which is responsible for a rapid intersystem crossing rate. Furthermore, these thiobase derivatives are characterized by the long-lived T1 state and the large energy gap for radiationless transition to ensure the generation of cytotoxic singlet oxygen.
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Affiliation(s)
- Xixi Cui
- School of Physics and Electronics, Shandong Normal University, Jinan 250358, PR China
| | - Jianzhong Fan
- School of Physics and Electronics, Shandong Normal University, Jinan 250358, PR China
| | - Yongkang Lyu
- School of Physics and Electronics, Shandong Normal University, Jinan 250358, PR China
| | - Xucong Zhou
- School of Basic Medical Sciences, Shandong Second Medical University, Weifang 261053, PR China
| | - Qingtian Meng
- School of Physics and Electronics, Shandong Normal University, Jinan 250358, PR China.
| | - Changzhe Zhang
- School of Physics and Electronics, Shandong Normal University, Jinan 250358, PR China.
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2
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Cadet J, Angelov D, Di Mascio P, Wagner JR. Contribution of oxidation reactions to photo-induced damage to cellular DNA. Photochem Photobiol 2024. [PMID: 38970297 DOI: 10.1111/php.13990] [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: 05/09/2024] [Revised: 06/14/2024] [Accepted: 06/15/2024] [Indexed: 07/08/2024]
Abstract
This review article is aimed at providing updated information on the contribution of immediate and delayed oxidative reactions to the photo-induced damage to cellular DNA/skin under exposure to UVB/UVA radiations and visible light. Low-intensity UVC and UVB radiations that operate predominantly through direct excitation of the nucleobases are very poor oxidizing agents giving rise to very low amounts of 8-oxo-7,8-dihydroguanine and DNA strand breaks with respect to the overwhelming bipyrimidine dimeric photoproducts. The importance of these two classes of oxidatively generated damage to DNA significantly increases together with a smaller contribution of oxidized pyrimidine bases upon UVA irradiation. This is rationalized in terms of sensitized photooxidation reactions predominantly mediated by singlet oxygen together with a small contribution of hydroxyl radical that appear to also be implicated in the photodynamic effects of the blue light component of visible light. Chemiexcitation-mediated formation of "dark" cyclobutane pyrimidine dimers in UVA-irradiated melanocytes is a recent major discovery that implicates in the initial stage, a delayed generation of reactive oxygen and nitrogen species giving rise to triplet excited carbonyl intermediate and possibly singlet oxygen. High-intensity UVC nanosecond laser radiation constitutes a suitable source of light to generate pyrimidine and purine radical cations in cellular DNA via efficient biphotonic ionization.
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Affiliation(s)
- Jean Cadet
- Département de Médecine nucléaire et Radiobiologie, Faculté de Médecine, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Dimitar Angelov
- Laboratoire de Biologie et de Modélisation de la Cellule LMBC, Ecole Normale Supérieure de Lyon, CNRS, Université de Lyon, Lyon, France
- Izmir Biomedicine and Genome Center IBG, Dokuz Eylul University, Balçova, Izmir, Turkey
| | - Paolo Di Mascio
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, Brazil
| | - J Richard Wagner
- Département de Médecine nucléaire et Radiobiologie, Faculté de Médecine, Université de Sherbrooke, Sherbrooke, Quebec, Canada
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3
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Polonius S, Lehrner D, González L, Mai S. Resolving Photoinduced Femtosecond Three-Dimensional Solute-Solvent Dynamics through Surface Hopping Simulations. J Chem Theory Comput 2024; 20:4738-4750. [PMID: 38768386 PMCID: PMC11171268 DOI: 10.1021/acs.jctc.4c00169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Revised: 04/22/2024] [Accepted: 05/07/2024] [Indexed: 05/22/2024]
Abstract
Photoinduced dynamics in solution is governed by mutual solute-solvent interactions, which give rise to phenomena like solvatochromism, the Stokes shift, dual fluorescence, or charge transfer. Understanding these phenomena requires simulating the solute's photoinduced dynamics and simultaneously resolving the three-dimensional solvent distribution dynamics. If using trajectory surface hopping (TSH) to this aim, thousands of trajectories are required to adequately sample the time-dependent three-dimensional solvent distribution functions, and thus resolve the solvent dynamics with sub-Ångstrom and femtosecond accuracy and sufficiently low noise levels. Unfortunately, simulating thousands of trajectories with TSH in the framework of hybrid quantum mechanical/molecular mechanical (QM/MM) can be prohibitively expensive when employing ab initio electronic structure methods. To tackle this challenge, we recently introduced a computationally efficient approach that combines efficient linear vibronic coupling models with molecular mechanics (LVC/MM) via electrostatic embedding [Polonius et al., JCTC 2023, 19, 7171-7186]. This method provides solvent-embedded, nonadiabatically coupled potential energy surfaces while scaling similarly to MM force fields. Here, we employ TSH with LVC/MM to unravel the photoinduced dynamics of two small thiocarbonyl compounds solvated in water. We describe how to estimate the number of trajectories required to produce nearly noise-free three-dimensional solvent distribution functions and present an analysis based on approximately 10,000 trajectories propagated for 3 ps. In the electronic ground state, both molecules exhibit in-plane hydrogen bonds to the sulfur atom. Shortly after excitation, these bonds are broken and reform perpendicular to the molecular plane on timescales that differ by an order of magnitude due to steric effects. We also show that the solvent relaxation dynamics is coupled to the electronic dynamics, including intersystem crossing. These findings are relevant to advance the understanding of the coupled solute-solvent dynamics of solvated photoexcited molecules, e.g., biologically relevant thio-nucleobases.
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Affiliation(s)
- Severin Polonius
- Institute
of Theoretical Chemistry, Faculty of Chemistry, University of Vienna, Währinger Str. 17, 1090 Vienna, Austria
- Vienna
Doctoral School in Chemistry (DoSChem), University of Vienna, Währinger Str. 42, 1090 Vienna, Austria
| | - David Lehrner
- Institute
of Theoretical Chemistry, Faculty of Chemistry, University of Vienna, Währinger Str. 17, 1090 Vienna, Austria
| | - Leticia González
- Institute
of Theoretical Chemistry, Faculty of Chemistry, University of Vienna, Währinger Str. 17, 1090 Vienna, Austria
- Vienna
Research Platform on Accelerating Photoreaction Discovery, University of Vienna, Währinger Straße 17, 1090 Vienna, Austria
| | - Sebastian Mai
- Institute
of Theoretical Chemistry, Faculty of Chemistry, University of Vienna, Währinger Str. 17, 1090 Vienna, Austria
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4
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Riera Aroche R, Ortiz García YM, Martínez Arellano MA, Riera Leal A. DNA as a perfect quantum computer based on the quantum physics principles. Sci Rep 2024; 14:11636. [PMID: 38773193 PMCID: PMC11109248 DOI: 10.1038/s41598-024-62539-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Accepted: 05/17/2024] [Indexed: 05/23/2024] Open
Abstract
DNA is a complex multi-resolution molecule whose theoretical study is a challenge. Its intrinsic multiscale nature requires chemistry and quantum physics to understand the structure and quantum informatics to explain its operation as a perfect quantum computer. Here, we present theoretical results of DNA that allow a better description of its structure and the operation process in the transmission, coding, and decoding of genetic information. Aromaticity is explained by the oscillatory resonant quantum state of correlated electron and hole pairs due to the quantized molecular vibrational energy acting as an attractive force. The correlated pairs form a supercurrent in the nitrogenous bases in a single band π -molecular orbital ( π -MO). The MO wave function ( Φ ) is assumed to be the linear combination of the n constituent atomic orbitals. The central Hydrogen bond between Adenine (A) and Thymine (T) or Guanine (G) and Cytosine (C) functions like an ideal Josephson Junction. The approach of a Josephson Effect between two superconductors is correctly described, as well as the condensation of the nitrogenous bases to obtain the two entangled quantum states that form the qubit. Combining the quantum state of the composite system with the classical information, RNA polymerase teleports one of the four Bell states. DNA is a perfect quantum computer.
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Affiliation(s)
- R Riera Aroche
- Department of Research in Physics, University of Sonora, Hermosillo, Sonora, Mexico
- Research and Higher Education Center of UNEPROP, Hermosillo, Sonora, Mexico
| | - Y M Ortiz García
- Research Institute of Dentistry, University of Guadalajara, Guadalajara Jalisco, Mexico
- Research and Higher Education Center of UNEPROP, Hermosillo, Sonora, Mexico
| | - M A Martínez Arellano
- General Hospital of the State of Sonora, Boulevar José María Escrivá de Balaguer 157, Colonia Villa del Palmar, C.P. 83105, Hermosillo, Sonora, Mexico
- Research and Higher Education Center of UNEPROP, Hermosillo, Sonora, Mexico
| | - A Riera Leal
- General Hospital of the State of Sonora, Boulevar José María Escrivá de Balaguer 157, Colonia Villa del Palmar, C.P. 83105, Hermosillo, Sonora, Mexico.
- Research and Higher Education Center of UNEPROP, Hermosillo, Sonora, Mexico.
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5
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Baños J, Avilés A, Colmenares F. Disruptive Model That Explains for the Long-Lived Triplet States Observed for 2-Thiocytosine upon UVA Radiation. ACS OMEGA 2024; 9:13059-13066. [PMID: 38524487 PMCID: PMC10955585 DOI: 10.1021/acsomega.3c09471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 01/17/2024] [Accepted: 02/23/2024] [Indexed: 03/26/2024]
Abstract
The possible role of radical species in the formation of the long-lived triplet states observed for 2-thiocytosine upon UV irradiation was theoretically investigated. It is predicted that the radical fragments arising from the homolytic rupture of the NH group of the thiobase can be yielded upon ultraviolet-A radiation. Recombination of the radicals through the most favorable singlet channel yields the lowest-lying tautomer of the 2-thiocytosine (the amino-thiol form) through a barrierless pathway. The rebounding of the radical fragments along the triplet channels that emerge from the attack of the hydrogen to the nitrogen atoms next to the C-S bond leads to stable structures for the amino-thion-N1H and amino-thion-N3H tautomers. These results allow for the rationalization of the near-unity triplet yields observed when this pure light-atom organic molecule is exposed to UV irradiation, without invoking intersystem crossings between the electronic states of different spin-multiplicities. A similar study for cytosine showed that the energy required to induce the homolytic breaking of the N-H bond of the nucleobase is not attainable under UVA radiation. This result is consistent with the experimental fact that no triplet states are observed when this molecule is exposed to that light.
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Affiliation(s)
- Jorge Baños
- Departamento de Física y Química
Teórica, Facultad de Química, Universidad Nacional Autónoma de México, CDMX 04510, Mexico
| | | | - Fernando Colmenares
- Departamento de Física y Química
Teórica, Facultad de Química, Universidad Nacional Autónoma de México, CDMX 04510, Mexico
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6
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Mayer D, Lever F, Gühr M. Time-resolved x-ray spectroscopy of nucleobases and their thionated analogs. Photochem Photobiol 2024; 100:275-290. [PMID: 38174615 DOI: 10.1111/php.13903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Revised: 12/20/2023] [Accepted: 12/21/2023] [Indexed: 01/05/2024]
Abstract
The photoinduced relaxation dynamics of nucleobases and their thionated analogs have been investigated extensively over the past decades motivated by their crucial role in organisms and their application in medical and biochemical research and treatment. Most of these studies focused on the spectroscopy of valence electrons and fragmentation. The advent of ultrashort x-ray laser sources such as free-electron lasers, however, opens new opportunities for studying the ultrafast molecular relaxation dynamics utilizing the site- and element-selectivity of x-rays. In this review, we want to summarize ultrafast experiments on thymine and 2-thiouracil performed at free-electron lasers. We performed time-resolved x-ray absorption spectroscopy at the oxygen K-edge after UV excitation of thymine. In addition, we investigated the excited state dynamics of 2-tUra via x-ray photoelectron spectroscopy at sulfur. For these methods, we show a strong sensitivity to the electronic state or charge distribution, respectively. We also performed time-resolved Auger-Meitner spectroscopy, which shows spectral shifts associated with internuclear distances close to the probed site. We discuss the complementary aspects of time-resolved x-ray spectroscopy techniques compared to optical and UV spectroscopy for the investigation of ultrafast relaxation processes.
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Affiliation(s)
- Dennis Mayer
- Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany
| | - Fabiano Lever
- Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany
| | - Markus Gühr
- Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany
- Institute of Physical Chemistry, University of Hamburg, Hamburg, Germany
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7
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Chang XP, Fan FR, Zhang TS, Xie BB. Quantum mechanics/molecular mechanics studies on the excited-state decay mechanisms of cytidine aza-analogues: 5-azacytidine and 2'-deoxy-5-azacytidine in aqueous solution. Phys Chem Chem Phys 2023; 25:26258-26269. [PMID: 37743787 DOI: 10.1039/d3cp03628f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/26/2023]
Abstract
The excited state properties and deactivation pathways of two DNA methylation inhibitors, i.e., 5-azacytidine (5ACyd) and 2'-deoxy-5-azacytidine (5AdCyd) in aqueous solution, are comprehensively explored with the QM(CASPT2//CASSCF)/MM protocol. We systematically map the feasible decay mechanisms based on the obtained excited-state decay paths involving all the identified minimum-energy structures, conical intersections, and crossing points driving the different internal conversion (IC) and intersystem crossing (ISC) routes in and between the 1ππ*, 1nπ*, 3ππ*, 3nπ*, and S0 states. Unlike the 1nπ* state below the 1ππ* state in 5ACyd, deoxyribose group substitution at the N1 position leads to the 1ππ* state becoming the S1 state in 5AdCyd. In 5ACyd and 5AdCyd, the initially populated 1ππ* state mainly deactivates to the S0 state through the direct 1ππ* → S0 IC or mediated by the 1nπ* state. The former nearly barrierless IC channel of 1ππ* → S0 occurs ultrafast via the nearby low-lying 1ππ*/S0 conical intersection. In the latter IC channel of 1ππ* → 1nπ* → S0, the initially photoexcited 1ππ* state first approaches the nearby S2/S1 conical section 1ππ*/1nπ* and then undergoes efficient IC to the 1nπ* state, followed by the further IC to the initial S0 state via the S1/S0 conical intersection 1nπ*/S0. The 1nπ*/S0 conical intersection is estimated to be located 6.0 and 4.9 kcal mol-1 above the 1nπ* state minimum in 5ACyd and 5AdCyd, respectively, at the QM(CASPT2)/MM level. In addition to the efficient singlet-mediated IC channels, the minor ISC routes would populate 1ππ* to T1(ππ*) through 1ππ* → T1 or 1ππ* → 1nπ* → T1. Relatively, the 1ππ* → 1nπ* → T1 route benefits from the spin-orbit coupling (SOC) of 1nπ*/3ππ* of 8.7 cm-1 in 5ACyd and 10.2 cm-1 in 5AdCyd, respectively. Subsequently, the T1 system will approach the nearby T1/S0 crossing point 3ππ*/S0 driving it back to the S0 state. Given the 3ππ*/S0 crossing point located above the T1 minimum and the small T1/S0 SOC, i.e., 8.4 kcal mol-1 and 2.1 cm-1 in 5ACyd and 6.8 kcal mol-1 and 1.9 cm-1 in 5AdCyd, respectively, the slow T1 → S0 would trap the system in the T1 state for a while. The present work could contribute to understanding the mechanistic photophysics and photochemistry of similar aza-nucleosides and their derivatives.
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Affiliation(s)
- Xue-Ping Chang
- College of Chemistry and Chemical Engineering, Xinyang Normal University, Xinyang 464000, China.
| | - Feng-Ran Fan
- College of Chemistry and Chemical Engineering, Xinyang Normal University, Xinyang 464000, China.
| | - Teng-Shuo Zhang
- College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, China
| | - Bin-Bin Xie
- Hangzhou Institute of Advanced Studies, Zhejiang Normal University, Hangzhou 311231, China
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8
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Ortiz-Rodríguez LA, Fang YG, Niogret G, Hadidi K, Hoehn SJ, Folkwein HJ, Jockusch S, Tor Y, Cui G, Levi L, Crespo-Hernández CE. Thieno[3,4- d]pyrimidin-4(3 H)-thione: an effective, oxygenation independent, heavy-atom-free photosensitizer for cancer cells. Chem Sci 2023; 14:8831-8841. [PMID: 37621444 PMCID: PMC10445467 DOI: 10.1039/d3sc02592f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Accepted: 07/24/2023] [Indexed: 08/26/2023] Open
Abstract
All-organic, heavy-atom-free photosensitizers based on thionation of nucleobases are receiving increased attention because they are easy to make, noncytotoxic, work both in the presence and absence of molecular oxygen, and can be readily incorporated into DNA and RNA. In this contribution, the DNA and RNA fluorescent probe, thieno[3,4-d]pyrimidin-4(1H)-one, has been thionated to develop thieno[3,4-d]pyrimidin-4(3H)-thione, which is nonfluorescent and absorbs near-visible radiation with about 60% higher efficiency. Steady-state absorption and emission spectra are combined with transient absorption spectroscopy and CASPT2 calculations to delineate the electronic relaxation mechanisms of both pyrimidine derivatives in aqueous and acetonitrile solutions. It is demonstrated that thieno[3,4-d]pyrimidin-4(3H)-thione efficiently populates the long-lived and reactive triplet state generating singlet oxygen with a quantum yield of about 80% independent of solvent. It is further shown that thieno[3,4-d]pyrimidin-4(3H)-thione exhibits high photodynamic efficacy against monolayer melanoma cells and cervical cancer cells both under normoxic and hypoxic conditions. Our combined spectroscopic, computational, and in vitro data demonstrate the excellent potential of thieno[3,4-d]pyrimidin-4(1H)-thione as a heavy-atom-free PDT agent and paves the way for further development of photosensitizers based on the thionation of thieno[3,4-d]pyrimidine derivatives. Collectively, the experimental and computational results demonstrate that thieno[3,4-d]pyrimidine-4(3H)-thione stands out as the most promising thiobase photosensitizer developed to this date.
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Affiliation(s)
| | - Ye-Guang Fang
- Key Lab of Theoretical and Computational Photochemistry, Ministry of Education, Chemistry College, Beijing Normal University Beijing 100875 China
| | - Germain Niogret
- Department of Chemistry and Biochemistry, University of California San Diego La Jolla CA 92093 USA
| | - Kaivin Hadidi
- Department of Chemistry and Biochemistry, University of California San Diego La Jolla CA 92093 USA
| | - Sean J Hoehn
- Department of Chemistry, Case Western Reserve University Cleveland OH 44106 USA
| | - Heather J Folkwein
- Department of Chemistry, Case Western Reserve University Cleveland OH 44106 USA
| | - Steffen Jockusch
- Center for Photochemical Sciences, Bowling Green State University Bowling Green Ohio 43403 USA
| | - Yitzhak Tor
- Department of Chemistry and Biochemistry, University of California San Diego La Jolla CA 92093 USA
| | - Ganglong Cui
- Key Lab of Theoretical and Computational Photochemistry, Ministry of Education, Chemistry College, Beijing Normal University Beijing 100875 China
| | - Liraz Levi
- Celloram Inc Cleveland OH 44106 USA
- Department of Pediatrics, Case Western Reserve University School of Medicine Cleveland Ohio 44106 USA
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9
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Chang XP, Zhao G, Zhang TS, Xie BB. Quantum mechanics/molecular mechanics studies on mechanistic photophysics of cytosine aza-analogues: 2,4-diamino-1,3,5-triazine and 2-amino-1,3,5-triazine in aqueous solution. Phys Chem Chem Phys 2023; 25:7669-7680. [PMID: 36857660 DOI: 10.1039/d2cp05639a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
The excited-state properties and photophysics of cytosine aza-analogues, i.e., 2,4-diamino-1,3,5-triazine (2,4-DT) and 2-amino-1,3,5-triazine (2-AT) in solution have been systematically explored using the QM(MS-CASPT2//CASSCF)/MM approach. The excited-state nonradiative relaxation mechanisms for the initially photoexcited S1(ππ*) state decay back to the S0 state are proposed in terms of the present computed minima, surface crossings (conical intersections and singlet-triplet crossings), and excited-state decay paths in the S1, S2, T1, T2, and S0 states. Upon photoexcitation to the bright S1(ππ*) state, 2,4-DT quickly relaxes to its S1 minimum and then overcomes a small energy barrier of 5.1 kcal mol-1 to approach a S1/S0 conical intersection, where the S1 system hops to the S0 state through S1 → S0 internal conversion (IC). In addition, at the S1 minimum, the system could partially undergo intersystem crossing (ISC) to the T1 state, followed by further ISC to the S0 state via the T1/S0 crossing point. In the T1 state, an energy barrier of 7.9 kcal mol-1 will trap 2,4-DT for a while. In parallel, for 2-AT, the system first relaxes to the S1 minimum and then S1 → S0 IC or S1 → T1 → S0 ISCs take place to the S0 state by surmounting a large barrier of 15.3 kcal mol-1 or 11.9 kcal mol-1, respectively, which heavily suppress electronic transition to the S0 state. Different from 2,4-DT, upon photoexcitation in the Franck-Condon region, 2-AT can quickly evolve in an essentially barrierless manner to nearby S2/S1 conical intersection, where the S2 and T1 states can be populated. Once it hops to the S2 state, the system will overcome a relatively small barrier (6.6 kcal mol-1vs. 15.3 kcal mol-1) through IC to the S0 state. Similarly, an energy barrier of 11.9 kcal mol-1 heavily suppresses the T1 state transformation to the S0 state. The present work manifests that the amination/deamination of the triazine rings can affect some degree of different vertical and adiabatic excitation energies and nonradiative decay pathways in solution. It not only rationalizes excited-state decay dynamics of 2,4-DT and 2-AT in aqueous solution but could also provide insights into the understanding of the photophysics of aza-nucleobases.
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Affiliation(s)
- Xue-Ping Chang
- College of Chemistry and Chemical Engineering, Xinyang Normal University, Xinyang 464000, China.
| | - Geng Zhao
- College of Chemistry and Chemical Engineering, Xinyang Normal University, Xinyang 464000, China.
| | - Teng-Shuo Zhang
- College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, China
| | - Bin-Bin Xie
- Hangzhou Institute of Advanced Studies, Zhejiang Normal University, Hangzhou 311231, China
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10
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Ultrafast Photo-Ion Probing of the Relaxation Dynamics in 2-Thiouracil. Molecules 2023; 28:molecules28052354. [PMID: 36903604 PMCID: PMC10005304 DOI: 10.3390/molecules28052354] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 02/19/2023] [Accepted: 02/20/2023] [Indexed: 03/08/2023] Open
Abstract
In this work, we investigate the relaxation processes of 2-thiouracil after UV photoexcitation to the S2 state through the use of ultrafast, single-colour, pump-probe UV/UV spectroscopy. We place focus on investigating the appearance and subsequent decay signals of ionized fragments. We complement this with VUV-induced dissociative photoionisation studies collected at a synchrotron, allowing us to better understand and assign the ionisation channels involved in the appearance of the fragments. We find that all fragments appear when single photons with energy > 11 eV are used in the VUV experiments and hence appear through 3+ photon-order processes when 266 nm light is used. We also observe three major decays for the fragment ions: a sub-autocorrelation decay (i.e., sub-370 fs), a secondary ultrafast decay on the order of 300-400 fs, and a long decay on the order of 220 to 400 ps (all fragment dependent). These decays agree well with the previously established S2 → S1 → Triplet → Ground decay process. Results from the VUV study also suggest that some of the fragments may be created by dynamics occurring in the excited cationic state.
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11
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Günsel A, Yazar B, Taslimi P, Erden Y, Taskin-Tok T, Pişkin H, Bilgiçli AT, Yarasir MN, Gülçin İ. Novel tetrakis-phthalocyanines bearing pyrimidine derivative: crystal XRD analysis, enzyme inhibition, molecular docking, and anticancer effects. J Biomol Struct Dyn 2023; 41:249-262. [PMID: 34806542 DOI: 10.1080/07391102.2021.2004923] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
In this study, the novel 4-(4-Aminopyrimidin-2-ylthio) phthalonitrile (1) as starting material was synthesized and its 3D structure was verified by the single crystal X-ray diffraction experiment. Then, its peripherally tetra-substituted phthalocyanines (2,3) and the methylated derivatives (2a,3a) containing pyrimidine derivative were synthesized. All these newly synthesized compounds were characterized with various spectroscopic methods such as UV-Vis, FT-IR, 1H-NMR, 13C-NMR and MALDI-TOF MS by obtaining satisfactory results. In addition, these novel phthalocyanines effectively inhibited acetylcholinesterase enzyme, with Ki values in the range of 10.43 ± 2.38 to 41.70 ± 9.32 µM. For the related enzyme, the IC50 values were obtained in the range of 11.68 to 44.28 µM. For α-glycosidase enzyme the most effective Ki values of (3a) and (2) were with Ki values of 92.87 ± 10.70 and 95.18 ± 17.83 µM, respectively. Indeed, the most potent phthalocyanines against both enzymes were recorded for the purpose of investigating interaction modes of these complexes in the active site of the target enzyme. The cytotoxicity potential of these phthalocyanines against human breast, colon, and prostate cancers demonstrated that these compounds had normal cytotoxic effects.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Armağan Günsel
- Department of Chemistry, Faculty of Arts and Sciences, Sakarya University, Serdivan, Sakarya, Turkey
| | - Bilge Yazar
- Department of Chemistry, Faculty of Arts and Sciences, Sakarya University, Serdivan, Sakarya, Turkey
| | - Parham Taslimi
- Department of Biotechnology, Faculty of Science, Bartin University, Bartin, Turkey.,Department of Chemistry, Faculty of Science, Istinye University, Istanbul, Turkey
| | - Yavuz Erden
- Department of Molecular Biology and Genetics, Faculty of Science, Bartin University, Bartin, Turkey
| | - Tugba Taskin-Tok
- Department of Chemistry, Faculty of Arts and Sciences, Gaziantep University, Gaziantep, Turkey.,Department of Bioinformatics and Computational Biology, Institute of Health Sciences, Gaziantep University, Gaziantep, Turkey
| | - Hasan Pişkin
- Department of Physics, Faculty of Arts and Sciences, Boğaziçi University, Beşiktaş, İstanbul, Turkey
| | - Ahmet T Bilgiçli
- Department of Chemistry, Faculty of Arts and Sciences, Sakarya University, Serdivan, Sakarya, Turkey
| | - M Nilüfer Yarasir
- Department of Chemistry, Faculty of Arts and Sciences, Sakarya University, Serdivan, Sakarya, Turkey
| | - İlhami Gülçin
- Department of Chemistry, Faculty of Science, Atatürk University, Erzurum, Turkey
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12
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Krancewicz K, Koput J, Hug GL, Marciniak B, Taras-Goslinska KM. Unusual photophysical properties of a new tricyclic derivative of thiopurines in terms of potential applications. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2022; 281:121620. [PMID: 35853257 DOI: 10.1016/j.saa.2022.121620] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 07/07/2022] [Accepted: 07/09/2022] [Indexed: 06/15/2023]
Abstract
The thio analogues of purine bases have been found to possess notable biological and pharmacological capabilities and have an important role to play as anticancer and immunosuppressive drugs. In this work a new tricyclic analogue of guanosine containing sulfur was synthesized, in particular, DTEG (2',3',5'-tri-O-acetyl-6,9-dithioethanoguanosine). Although there is promise for thiopurine derivatives for biomedical applications, there are some liabilities in regard to their exposure to light. As a preliminary survey for such difficulties with DTEG, this work looks into spectral and photophysical processes of DTEG using time-resolved and steady-state optical excitation. In contrast to other thiopurines, which have long-lived triplets, DTEG is shown to have a short-lived triplet making it less dangerous for singlet-oxygen sensitization. Even in anaerobic solutions, its photoreactivity is negligible. These various unusual photochemical properties of DTEG are consistent with DTEG being very promising as an alternative drug to the currently used 6-thiopurines. DTEG also has some interesting photophysical behavior that is distinct from other thioketones. Although thioketones have an unusual fluorescence violating Kasha's Rule and emitting from the second excited singlet state, DTEG does this also, but, in addition, it shows dual fluorescence by emitting from its first excited singlet as well. The assignments of the nature of these excited states are supported by DFT results. This theory and associated kinetic analysis show quantitatively that the dual fluorescence is, in part, tied to the relatively fast S2 to S1 internal conversion compared to other S2 decays and, in part, tied to the relatively slow nonradiative decay of S1 itself.
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Affiliation(s)
| | - Jacek Koput
- Faculty of Chemistry, Adam Mickiewicz University, 61-614 Poznan, Poland
| | - Gordon L Hug
- Radiation Laboratory, University of Notre Dame, Notre Dame 46556, USA
| | - Bronisław Marciniak
- Faculty of Chemistry, Adam Mickiewicz University, 61-614 Poznan, Poland; Centre for Advanced Technology, Adam Mickiewicz University, 61-614 Poznan, Poland
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13
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Ullrich S, Qu Y, Mohamadzade A, Shrestha S. The Effect of Methylation on the Triplet-State Dynamics of 2-Thiouracil: Time-Resolved Photoelectron Spectroscopy of 2-Thiothymine. J Phys Chem A 2022; 126:8211-8217. [DOI: 10.1021/acs.jpca.2c06051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Susanne Ullrich
- Department of Physics and Astronomy, University of Georgia, Athens, Georgia 30602, United States
| | - Yingqi Qu
- Department of Physics and Astronomy, University of Georgia, Athens, Georgia 30602, United States
| | - Abed Mohamadzade
- Department of Physics and Astronomy, University of Georgia, Athens, Georgia 30602, United States
| | - Sarita Shrestha
- Department of Physics and Astronomy, University of Georgia, Athens, Georgia 30602, United States
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14
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Wu P, Wang X, Pan H, Chen J. Direct Observation of Excitation Wavelength-Dependent Ultrafast Intersystem Crossing in Cytosine Nucleoside Solution. J Phys Chem B 2022; 126:7975-7980. [PMID: 36179273 DOI: 10.1021/acs.jpcb.2c05865] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A triplet excited state can lead to different DNA photolesions, especially in cytosine and its nucleoside/nucleotide as they are hotspots for DNA mutations. However, the triplet state generation mechanism is in controversy, and experimental evidence of ultrafast intersystem crossing (ISC) has not been registered in these molecules. In this work, ultrafast ISC is directly observed in 2'-deoxycytidine (dCyd) solution by using femtosecond transient absorption spectroscopy. Surprisingly, we demonstrate that ISC in dCyd is sensitive to the excitation wavelength, and a spin-vibronic ISC mechanism is proposed. This finding is the last piece of the dCyd excited-state deactivation mechanism puzzle and sets the base for further investigation of triplet state-involved photophysics and photochemistry in dCyd-containing DNA.
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Affiliation(s)
- Peicong Wu
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Xueli Wang
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Haifeng Pan
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Jinquan Chen
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China.,Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, China
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15
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Mayer D, Picconi D, Robinson MS, Gühr M. Experimental and theoretical gas-phase absorption spectra of thionated uracils. Chem Phys 2022. [DOI: 10.1016/j.chemphys.2022.111500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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16
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Wang D, Wang X, Jiang Y, Cao S, Jin P, Pan H, Sun H, Sun Z, Chen J. Excited State Dynamics of Methylated Guanosine Derivatives Revealed by Femtosecond Time-resolved Spectroscopy. Photochem Photobiol 2022; 98:1008-1016. [PMID: 35203108 DOI: 10.1111/php.13612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 02/20/2022] [Indexed: 11/28/2022]
Abstract
Methylated DNA/RNA nucleobases are important epigenetic marks in living species and play an important role for targeted therapies. Moreover, they could bring significant changes to the photo-stability of nucleic acid, leading these sites become mutational hotspots for disease such as skin cancer. While a number of studies have demonstrated the relationship between excited state dynamics and the biological function of methylated cytosine in DNA, investigations aimed at unraveling the excited state dynamics of methylated guanosine in RNA have been largely overlooked. In this work, influence of methylation on the excited state dynamics of guanosine is studied by using femtosecond time-resolved spectroscopy. Our results suggest that the effect of methyl substitution on the photophysical properties of guanosine is position sensitive. N1-methylguanosine shows very similar excited state dynamics as that in guanosine, while almost one order of magnitude longer lifetime of the La state is observed in N2, N2-dimethylguanosine. Notably, N7-methylation can lead to a new minimum on the La state, which shows a two orders of magnitude longer excited state lifetime compared with guanosine. These findings not only help understanding excited state dynamics of methylated guanosines, but also lay the foundation for further studying DNA/RNA strands incorporated with these bases.
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Affiliation(s)
- Danhong Wang
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, 200062, China
| | - Xueli Wang
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, 200062, China
| | - Yanrong Jiang
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, 200062, China
| | - Simin Cao
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, 200062, China
| | - Peipei Jin
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, 200062, China
| | - Haifeng Pan
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, 200062, China
| | - Haitao Sun
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, 200062, China
| | - Zhenrong Sun
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, 200062, China
| | - Jinquan Chen
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, 200062, China.,Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi, 030006, China
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17
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On the Photostability of Cyanuric Acid and Its Candidature as a Prebiotic Nucleobase. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27041184. [PMID: 35208973 PMCID: PMC8875432 DOI: 10.3390/molecules27041184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/19/2021] [Revised: 02/02/2022] [Accepted: 02/05/2022] [Indexed: 11/28/2022]
Abstract
Cyanuric acid is a triazine derivative that has been identified from reactions performed under prebiotic conditions and has been proposed as a prospective precursor of ancestral RNA. For cyanuric acid to have played a key role during the prebiotic era, it would have needed to survive the harsh electromagnetic radiation conditions reaching the Earth’s surface during prebiotic times (≥200 nm). Therefore, the photostability of cyanuric acid would have been crucial for its accumulation during the prebiotic era. To evaluate the putative photostability of cyanuric acid in water, in this contribution, we employed density functional theory (DFT) and its time-dependent variant (TD-DFT) including implicit and explicit solvent effects. The calculations predict that cyanuric acid has an absorption maximum at ca. 160 nm (7.73 eV), with the lowest-energy absorption band extending to ca. 200 nm in an aqueous solution and exhibiting negligible absorption at longer wavelengths. Excitation of cyanuric acid at 160 nm or longer wavelengths leads to the population of S5,6 singlet states, which have ππ* character and large oscillator strengths (0.8). The population reaching the S5,6 states is expected to internally convert to the S1,2 states in an ultrafast time scale. The S1,2 states, which have nπ* character, are predicted to access a conical intersection with the ground state in a nearly barrierless fashion (ca. ≤ 0.13 eV), thus efficiently returning the population to the ground state. Furthermore, based on calculated spin–orbit coupling elements of ca. 6 to 8 cm−1, the calculations predict that intersystem crossing to the triplet manifold should play a minor role in the electronic relaxation of cyanuric acid. We have also calculated the vertical ionization energy of cyanuric acid at 8.2 eV, which predicts that direct one-photon ionization of cyanuric acid should occur at ca. 150 nm. Collectively, the quantum-chemical calculations predict that cyanuric acid would have been highly photostable under the solar radiation conditions reaching the Earth’s surface during the prebiotic era in an aqueous solution. Of relevance to the chemical origin of life and RNA-first theories, these observations lend support to the idea that cyanuric acid could have accumulated in large quantities during the prebiotic era and thus strengthens its candidature as a relevant prebiotic nucleobase.
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18
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Günsel A, Yıldırım A, Taslimi P, Erden Y, Taskin-Tok T, Pişkin H, Bilgiçli AT, Gülçin İ, Nilüfer Yarasir M. Cytotoxicity effects and biochemical investigation of novel tetrakis-phthalocyanines bearing 2-thiocytosine moieties with molecular docking studies. INORG CHEM COMMUN 2022. [DOI: 10.1016/j.inoche.2022.109263] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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19
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Nam Y, Keefer D, Nenov A, Conti I, Aleotti F, Segatta F, Lee JY, Garavelli M, Mukamel S. Conical Intersection Passages of Molecules Probed by X-ray Diffraction and Stimulated Raman Spectroscopy. J Phys Chem Lett 2021; 12:12300-12309. [PMID: 34931839 DOI: 10.1021/acs.jpclett.1c03814] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Conical intersections (CoIns) play an important role in ultrafast relaxation channels. Their monitoring remains a formidable experimental challenge. We theoretically compare the probing of the S2 → S1 CoIn passage in 4-thiouracil by monitoring its vibronic coherences, using off-resonant X-ray-stimulated Raman spectroscopy (TRUECARS) and time-resolved X-ray diffraction (TRXD). The quantum nuclear wavepacket (WP) dynamics provides an accurate picture of the photoinduced dynamics. Upon photoexcitation, the WP oscillates among the Franck-Condon point, the S2 minimum, and the CoIn with a 70 fs period. A vibronic coherence first emerges at 20 fs and can be observed until the S2 state is fully depopulated. The distribution of the vibronic frequencies involved in the coherence is recorded by the TRUECARS spectrogram. The TRXD signal provides spatial images of electron densities associated with the CoIn. In combination, the two signals provide a complementary picture of the nonadiabatic passage, which helps in the study of the underlying photophysics in thiobases.
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Affiliation(s)
- Yeonsig Nam
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
- Convergence Research Center for Energy and Environmental Sciences, Sungkyunkwan University, Suwon 16419, Korea
| | - Daniel Keefer
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
| | - Artur Nenov
- Dipartimento di Chimica Industriale "Toso Montanari," Universita' degli Studi di Bologna, I-40136 Bologna, Italy
| | - Irene Conti
- Dipartimento di Chimica Industriale "Toso Montanari," Universita' degli Studi di Bologna, I-40136 Bologna, Italy
| | - Flavia Aleotti
- Dipartimento di Chimica Industriale "Toso Montanari," Universita' degli Studi di Bologna, I-40136 Bologna, Italy
| | - Francesco Segatta
- Dipartimento di Chimica Industriale "Toso Montanari," Universita' degli Studi di Bologna, I-40136 Bologna, Italy
| | - Jin Yong Lee
- Convergence Research Center for Energy and Environmental Sciences, Sungkyunkwan University, Suwon 16419, Korea
- Department of Chemistry, Sungkyunkwan University, Suwon 16419, Korea
| | - Marco Garavelli
- Dipartimento di Chimica Industriale "Toso Montanari," Universita' degli Studi di Bologna, I-40136 Bologna, Italy
| | - Shaul Mukamel
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
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20
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Borrego-Varillas R, Nenov A, Kabaciński P, Conti I, Ganzer L, Oriana A, Jaiswal VK, Delfino I, Weingart O, Manzoni C, Rivalta I, Garavelli M, Cerullo G. Tracking excited state decay mechanisms of pyrimidine nucleosides in real time. Nat Commun 2021; 12:7285. [PMID: 34907186 PMCID: PMC8671501 DOI: 10.1038/s41467-021-27535-7] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 11/24/2021] [Indexed: 11/18/2022] Open
Abstract
DNA owes its remarkable photostability to its building blocks-the nucleosides-that efficiently dissipate the energy acquired upon ultraviolet light absorption. The mechanism occurring on a sub-picosecond time scale has been a matter of intense debate. Here we combine sub-30-fs transient absorption spectroscopy experiments with broad spectral coverage and state-of-the-art mixed quantum-classical dynamics with spectral signal simulations to resolve the early steps of the deactivation mechanisms of uridine (Urd) and 5-methyluridine (5mUrd) in aqueous solution. We track the wave packet motion from the Franck-Condon region to the conical intersections (CIs) with the ground state and observe spectral signatures of excited-state vibrational modes. 5mUrd exhibits an order of magnitude longer lifetime with respect to Urd due to the solvent reorganization needed to facilitate bulky methyl group motions leading to the CI. This activates potentially lesion-inducing dynamics such as ring opening. Involvement of the 1nπ* state is found to be negligible.
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Affiliation(s)
| | - Artur Nenov
- Dipartimento di Chimica Industriale, Università degli Studi di Bologna, Viale del Risorgimento 4, Bologna, Italy
| | - Piotr Kabaciński
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, Milano, Italy
| | - Irene Conti
- Dipartimento di Chimica Industriale, Università degli Studi di Bologna, Viale del Risorgimento 4, Bologna, Italy
| | - Lucia Ganzer
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, Milano, Italy
| | - Aurelio Oriana
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, Milano, Italy
| | - Vishal Kumar Jaiswal
- Dipartimento di Chimica Industriale, Università degli Studi di Bologna, Viale del Risorgimento 4, Bologna, Italy
| | - Ines Delfino
- Dipartimento di Scienze Ecologiche e Biologiche, Università della Tuscia, Via San Camillo de Lellis, snc, Viterbo, Italy
| | - Oliver Weingart
- Institut für Theoretische Chemie und Computerchemie, Heinrich Heine Universität Düsseldorf, Universitätsstrasse 1, Düsseldorf, Germany
| | | | - Ivan Rivalta
- Dipartimento di Chimica Industriale, Università degli Studi di Bologna, Viale del Risorgimento 4, Bologna, Italy
- Université de Lyon, École Normale Supérieure de Lyon, CNRS UMR 5182, Laboratoire de Chimie, 46 allée d'Italie, F69364, Lyon, France
| | - Marco Garavelli
- Dipartimento di Chimica Industriale, Università degli Studi di Bologna, Viale del Risorgimento 4, Bologna, Italy.
| | - Giulio Cerullo
- IFN-CNR, Piazza Leonardo da Vinci 32, Milano, Italy.
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, Milano, Italy.
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21
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Ortiz-Rodríguez LA, Hoehn SJ, Acquah C, Abbass N, Waidmann L, Crespo-Hernández CE. Femtosecond intersystem crossing to the reactive triplet state of the 2,6-dithiopurine skin cancer photosensitizer. Phys Chem Chem Phys 2021; 23:25048-25055. [PMID: 34730146 DOI: 10.1039/d1cp04415j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Site-selected sulfur-substituted nucleobases are a class of all organic, heavy-atom-free photosensitizers for photodynamic therapy applications that exhibit excellent photophysical properties such as strong absorption in the ultraviolet-A region of the electromagnetic spectrum, near-unity triplet yields, and a high yield of singlet oxygen generation. Recent investigations on doubly thionated nucleobases, 2,4-dithiothymine, 2,4-dithiouracil, and 2,6-dithiopurine, demonstrated that these set of dithionated nucleobases outperform the photodynamic efficacy exhibit by 4-thiothymidine-the most widely studied singly substituted thiobase to date. Out of the three dithionated nucleobases, 2,6-dithiopurine was shown to be the most effective, exhibiting inhibition of cell proliferation of up to 63% when combined with a low UVA dose of 5 J cm-2. In this study, we elucidated the electronic relaxation pathways leading to the population of the reactive triplet state of 2,6-dithiopurine. 2,6-Dithiopurine populates the triplet manifold in less than 150 fs, reaching the nπ* triplet state minimum within a lifetime of 280 ± 50 fs. Subsequently, the population in the nπ* triplet state minimum internally converts to the long-lived ππ* triplet state within a lifetime of 3 ± 1 ps. The relatively slow internal conversion lifetime is associated with major conformational relaxation in going from the nπ* to ππ* triplet state minimum. A unity triplet yield of 1.0 ± 0.1 is measured.
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Affiliation(s)
| | - Sean J Hoehn
- Department of Chemistry, Case Western Reserve University, Cleveland, OH 44106, USA.
| | - Chris Acquah
- Department of Chemistry, Case Western Reserve University, Cleveland, OH 44106, USA.
| | - Nadia Abbass
- Department of Chemistry, Case Western Reserve University, Cleveland, OH 44106, USA.
| | - Lidia Waidmann
- Department of Chemistry, Case Western Reserve University, Cleveland, OH 44106, USA.
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22
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Xu T, Hu Z, Lv M, Zhou Z, Xu J, Sun Z, Sun H, Chen J. Hydrogen atom and water complex determine the excited state dynamics of 8-azaguanine. Chem Phys 2021. [DOI: 10.1016/j.chemphys.2021.111118] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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23
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Zhang K, Wang F, Jiang Y, Wang X, Pan H, Sun Z, Sun H, Xu J, Chen J. New Insights about the Photostability of DNA/RNA Bases: Triplet nπ* State Leads to Effective Intersystem Crossing in Pyrimidinones. J Phys Chem B 2021; 125:2042-2049. [PMID: 33600186 DOI: 10.1021/acs.jpcb.0c10611] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The high photostability of DNA/RNA nucleobases is attributed to the effective internal conversions of their bright 1ππ* states to the ground state through conical intersections. Intersystem crossing (ISC) from singlet to triplet excited states is a minor decay pathway in nucleobases and it is observed with ∼1-2% quantum yields (QYs) in pyrimidine bases. Presumably, ISC in pyrimidines takes place from the dark singlet 1nπ* state to the lowest triplet 3ππ* state. However, recent studies showed that ISC from the initial populated bright 1ππ* state to higher energy triplet 3nπ* states indeed occurs in the subpicosecond timescale. Such a mechanism is still poorly understood since direct observation of this pathway is challenging. Herein, excited state dynamics of three pyrimidinones, which share the same skeleton with pyrimidine bases, is investigated in different solvents. Compared to canonical pyrimidine bases, removing the oxygen atom at the C4 position revokes the low-lying dark 1nπ* state in pyrimidinones, resulting in direct ISC from the S1 (1ππ*) state to triplet T3 (3nπ*) state with much higher QYs. Meanwhile, hydrogen bonding between the carbonyl group in pyrimidinones and protic solvents can accelerate vibrational cooling of the hot S1 (1ππ*) state, leading to higher fluorescence QYs and smaller ISC rate constants. These results not only evidence the hypothesis of the direct 1ππ* → 3nπ* ISC mechanism, but also contribute to a better understanding of triplet formation in pyrimidines.
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Affiliation(s)
- Kun Zhang
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Fufang Wang
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Yanrong Jiang
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Xueli Wang
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Haifeng Pan
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Zhenrong Sun
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Haitao Sun
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Jianhua Xu
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China.,Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, China
| | - Jinquan Chen
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China.,Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, China
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24
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Ortiz-Rodríguez LA, Hoehn SJ, Loredo A, Wang L, Xiao H, Crespo-Hernández CE. Electronic Relaxation Pathways in Heavy-Atom-Free Photosensitizers Absorbing Near-Infrared Radiation and Exhibiting High Yields of Singlet Oxygen Generation. J Am Chem Soc 2021; 143:2676-2681. [PMID: 33587618 PMCID: PMC7985834 DOI: 10.1021/jacs.0c13203] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Heavy-atom-free photosensitizers (HAF-PSs) based on thionation of carbonyl groups of readily accessible organic compounds are rapidly emerging as a versatile class of molecules. However, their photochemical properties and electronic relaxation mechanisms are currently unknown. Investigating the excited-state dynamics is essential to understand their benefits and limitations and to develop photosensitizers with improved photochemical properties. Herein, the photochemical and electronic-structure properties of two of the most promising HAF-PSs developed to date are revealed. It is shown that excitation of thio-4-(dimethylamino)naphthalamide and thionated Nile Red with near-infrared radiation leads to the efficient population of the triplet manifold through multiple relaxation pathways in hundreds of femtoseconds. The strong singlet-triplet couplings in this family of photosensitizers should enable a broad range of applications, including in photodynamic therapy, photocatalysis, photovoltaics, organic LEDs, and photon up-conversion.
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Affiliation(s)
- Luis A. Ortiz-Rodríguez
- Department of Chemistry, Case Western Reserve University, Cleveland, Ohio 44106, United States
| | - Sean J. Hoehn
- Department of Chemistry, Case Western Reserve University, Cleveland, Ohio 44106, United States
| | - Axel Loredo
- Department of Chemistry, Rice University, Houston, Texas 77005, United States
| | - Lushun Wang
- Department of Chemistry, Rice University, Houston, Texas 77005, United States
| | - Han Xiao
- Department of Chemistry, Department of Biosciences, and Department of Bioengineering, Rice University, Houston, Texas 77005, United States
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25
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Vos E, Scott TR, González-Vázquez J, Corral I, Truhlar DG, Gagliardi L. Intrastrand Photolesion Formation in Thio-Substituted DNA: A Case Study Including Single-Reference and Multireference Methods. J Phys Chem A 2020; 124:10422-10433. [PMID: 33284609 DOI: 10.1021/acs.jpca.0c06814] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The substitution of canonical nucleobases by thiated analogues in natural DNA has been exploited in pharmacology, photochemotherapy, and structural biology. Thionucleobases react with adjacent thymines leading to 6-4 pyrimidine-pyrimidone photoproducts (6-4PPs), which are a major source of DNA photodamage, in particular intrastrand cross-linked photolesions. Here, we study the mechanism responsible for the formation of 6-4PPs in thionucleobases by employing quantum-mechanical calculations. We use multiconfiguration pair-density functional theory, complete active space second-order perturbation theory, and Kohn-Sham density functional theory. Scrutinizing the photochemistry of thionucleobases can elucidate the reaction mechanism of these prodrugs and identify the role that triplet excited states play in the generation of photolesions in the natural biopolymer. Three different possible mechanisms to generate the 6-4PPs are presented, and we conclude that the use of multireference approaches is indispensable to capture important features of the potential energy surface.
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Affiliation(s)
- Eva Vos
- Departamento de Química, Módulo 13, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Thais R Scott
- Department of Chemistry, Pritzker School of Molecular Engineering, James Franck Institute, Chicago Center for Theoretical Chemistry, The University of Chicago, 5735 S Ellis Ave., Chicago, Illinois 60637, United States
| | - Jesús González-Vázquez
- Departamento de Química, Módulo 13, Universidad Autónoma de Madrid, 28049 Madrid, Spain.,Institute of Advanced Chemical Sciences (IadChem), Universidad Autónoma de Madrid, Campus de Excelencia UAM-CSIC, Cantoblanco, 28049 Madrid, Spain
| | - Inés Corral
- Departamento de Química, Módulo 13, Universidad Autónoma de Madrid, 28049 Madrid, Spain.,Institute of Advanced Chemical Sciences (IadChem), Universidad Autónoma de Madrid, Campus de Excelencia UAM-CSIC, Cantoblanco, 28049 Madrid, Spain
| | - Donald G Truhlar
- Department of Chemistry, Chemical Theory Center, and Minnesota Supercomputing Institute, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455-0431, United States
| | - Laura Gagliardi
- Department of Chemistry, Pritzker School of Molecular Engineering, James Franck Institute, Chicago Center for Theoretical Chemistry, The University of Chicago, 5735 S Ellis Ave., Chicago, Illinois 60637, United States
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26
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Shen L, Xie B, Li Z, Liu L, Cui G, Fang WH. Role of Multistate Intersections in Photochemistry. J Phys Chem Lett 2020; 11:8490-8501. [PMID: 32787313 DOI: 10.1021/acs.jpclett.0c01637] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
It has been generally accepted that the intersection of potential energy surfaces can facilitate nonadiabatic transitions and plays a crucial role in photochemistry. Although most previous studies have focused on the conical intersection of two electronic states, multistate intersections are common in polyatomic molecules, and their key roles in photochemistry have been uncovered by electronic structure calculations and nonadiabatic dynamics simulations. In this Perspective, the algorithms for searching two- or three-state intersections are first examined with an emphasis on the latest development in a general algorithm for location of multistate intersections. Then, we focus on intersystem crossing (ISC) that occurs in the region of multistate intersection, paying more attention to how the state-specific spin-orbit coupling interaction influences nonadiabatic ISC processes. Finally, the interweaving of nonadiabatic dynamics simulation and electronic structure calculation has been recognized as a correct way to ascertain the vital roles of multistate intersections in photochemical reactions.
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Affiliation(s)
- Lin Shen
- Key Laboratory of Theoretical and Computational Photochemistry of Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, P.R. China
| | - Binbin Xie
- Hangzhou Institute of Advanced Studies, Zhejiang Normal University, 1108 Gengwen Road, Hangzhou 311231, Zhejiang, P.R. China
| | - Ziwen Li
- Key Laboratory of Theoretical and Computational Photochemistry of Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, P.R. China
| | - Lihong Liu
- Key Laboratory of Theoretical and Computational Photochemistry of Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, P.R. China
| | - Ganglong Cui
- Key Laboratory of Theoretical and Computational Photochemistry of Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, P.R. China
| | - Wei-Hai Fang
- Key Laboratory of Theoretical and Computational Photochemistry of Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, P.R. China
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27
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Peng Q, Zhu YH, Zhang TS, Liu XY, Fang WH, Cui G. Selenium substitution effects on excited-state properties and photophysics of uracil: a MS-CASPT2 study. Phys Chem Chem Phys 2020; 22:12120-12128. [PMID: 32440669 DOI: 10.1039/d0cp01369b] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The photophysics of selenium-substituted nucleobases has attracted recent experimental attention because they could serve as potential photosensitizers in photodynamic therapy. Herein, we present a comprehensive MS-CASPT2 study on the spectroscopic and excited-state properties, and photophysics of 2-selenouracil (2SeU), 4-selenouracil (4SeU), and 2,4-selenouracil (24SeU). Relevant minima, conical intersections, crossing points, and excited-state relaxation paths in the lowest five electronic states (i.e., S0, S1, S2, T2, and T1) are explored. On the basis of these results, their photophysical mechanisms are proposed. Upon photoirradiation to the bright S2 state, 2SeU quickly relaxes to its S2 minimum and then moves in an essentially barrierless way to a nearby S2/S1 conical intersection near which the S1 state is populated. Next, the S1 system arrives at an S1/T2/T1 intersection where a large S1/T1 spin-orbit coupling of 430.8 cm-1 makes the T1 state populated. In this state, a barrier of 6.8 kcal mol-1 will trap 2SeU for a while. In parallel, for 4SeU or 24SeU, the system first relaxes to the S2 minimum and then overcomes a small barrier to approach an S2/S1 conical intersection. Once hopping to the S1 state, there exists an extended region with very close S1, T2, and T1 energies. Similarly, a large S1/T1 spin-orbit coupling of 426.8 cm-1 drives the S1→ T1 intersystem crossing process thereby making the T1 state populated. Similarly, an energy barrier heavily suppresses electronic transition to the S0 state. The present work manifests that different selenium substitutions on uracil can lead to a certain extent of different vertical and adiabatic excitation energies, excited-state properties, and relaxation pathways. These insights could help understand the photophysics of selenium-substituted nucleobases.
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Affiliation(s)
- Qin Peng
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China.
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28
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Fu L, Wang Z, Liu Y, Wang X, Xu R, Liu W, Chen J, Xu J. Observation of triplet nπ* state in ultrafast intersystem crossing of 6-azathymine. J Photochem Photobiol A Chem 2020. [DOI: 10.1016/j.jphotochem.2020.112491] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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29
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Xu R, Hu Z, Wang X, Liu Y, Zhou Z, Xu J, Sun Z, Sun H, Chen J. Intramolecular Charge Transfer in 5-Halogen Cytidines Revealed by Femtosecond Time-Resolved Spectroscopy. J Phys Chem B 2020; 124:2560-2567. [DOI: 10.1021/acs.jpcb.0c00455] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Rui Xu
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China
| | - Zhubin Hu
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China
| | - Xueli Wang
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China
| | - Yufeng Liu
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China
| | - Zhongneng Zhou
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China
| | - Jianhua Xu
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, China
| | - Zhenrong Sun
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China
| | - Haitao Sun
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China
- NYU-ECNU Center for Computational Chemistry at NYU Shanghai, Shanghai 200062, China
| | - Jinquan Chen
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, China
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30
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Brister MM, Gustavsson T, Crespo-Hernández CE. Excited State Lifetimes of Sulfur-Substituted DNA and RNA Monomers Probed Using the Femtosecond Fluorescence Up-Conversion Technique. Molecules 2020; 25:E584. [PMID: 32013184 PMCID: PMC7037914 DOI: 10.3390/molecules25030584] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 01/23/2020] [Accepted: 01/26/2020] [Indexed: 11/16/2022] Open
Abstract
Sulfur-substituted DNA and RNA nucleobase derivatives (a.k.a., thiobases) are an important family of biomolecules. They are used as prodrugs and as chemotherapeutic agents in medical settings, and as photocrosslinker molecules in structural-biology applications. Remarkably, excitation of thiobases with ultraviolet to near-visible light results in the population of long-lived and reactive triplet states on a time scale of hundreds of femtoseconds and with near-unity yields. This efficient nonradiative decay pathway explains the vanishingly small fluorescence yields reported for the thiobases and the scarcity of fluorescence lifetimes in the literature. In this study, we report fluorescence lifetimes for twelve thiobase derivatives, both in aqueous solution at physiological pH and in acetonitrile. Excitation is performed at 267 and 362 nm, while fluorescence emission is detected at 380, 425, 450, 525, or 532 nm. All the investigated thiobases reveal fluorescence lifetimes that decay in a few hundreds of femtoseconds and with magnitudes that depend and are sensitive to the position and degree of sulfur-atom substitution and on the solvent environment. Interestingly, however, three thiopyrimidine derivatives (i.e., 2-thiocytidine, 2-thiouridine, and 4-thiothymidine) also exhibit a small amplitude fluorescence component of a few picoseconds in aqueous solution. Furthermore, the N-glycosylation of thiobases to form DNA or RNA nucleoside analogues is demonstrated as affecting their fluorescence lifetimes. In aqueous solution, the fluorescence decay signals exciting at 267 nm are equal or slower than those collected exciting at 362 nm. In acetonitrile, however, the fluorescence decay signals recorded upon 267 nm excitation are, in all cases, faster than those measured exciting at 362 nm. A comparison to the literature values show that, while both the DNA and RNA nucleobase and thiobase derivatives exhibit sub-picosecond fluorescence lifetimes, the 1ππ* excited-state population in the nucleobase monomers primarily decay back to the ground state, whereas it predominantly populates long-lived and reactive triplet states in thiobase monomers.
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Affiliation(s)
- Matthew M. Brister
- Department of Chemistry, Case Western Reserve University, 10900 Euclid Ave., Cleveland, OH 44106, USA;
| | - Thomas Gustavsson
- LIDYL, CEA, CNRS, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France
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31
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Teles‐Ferreira DC, Conti I, Borrego‐Varillas R, Nenov A, Van Stokkum IHM, Ganzer L, Manzoni C, Paula AM, Cerullo G, Garavelli M. A Unified Experimental/Theoretical Description of the Ultrafast Photophysics of Single and Double Thionated Uracils. Chemistry 2019; 26:336-343. [DOI: 10.1002/chem.201904541] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Indexed: 12/28/2022]
Affiliation(s)
- Danielle Cristina Teles‐Ferreira
- Departamento de Física Universidade Federal de Minas Gerais 31270-901 Belo Horizonte MG Brazil
- Electrical Engineering Department Federal Institute of Minas Gerais Formiga MG Brazil
| | - Irene Conti
- Dipartimento di Chimica Industriale Università degli Studi di Bologna Viale del Risorgimento 4 40136 Bologna Italy
| | - Rocío Borrego‐Varillas
- IFN-CNR Department of Physics Politecnico di Milano P.za L. da Vinci 32 20133 Milano Italy
| | - Artur Nenov
- Dipartimento di Chimica Industriale Università degli Studi di Bologna Viale del Risorgimento 4 40136 Bologna Italy
| | - Ivo H. M. Van Stokkum
- Department of Physics and Astronomy Faculty of Sciences Vrije Universiteit Amsterdam De Boelelaan 1081 1081HV Amsterdam The Netherlands
| | - Lucia Ganzer
- IFN-CNR Department of Physics Politecnico di Milano P.za L. da Vinci 32 20133 Milano Italy
| | - Cristian Manzoni
- IFN-CNR Department of Physics Politecnico di Milano P.za L. da Vinci 32 20133 Milano Italy
| | - Ana Maria Paula
- Departamento de Física Universidade Federal de Minas Gerais 31270-901 Belo Horizonte MG Brazil
| | - Giulio Cerullo
- IFN-CNR Department of Physics Politecnico di Milano P.za L. da Vinci 32 20133 Milano Italy
| | - Marco Garavelli
- Dipartimento di Chimica Industriale Università degli Studi di Bologna Viale del Risorgimento 4 40136 Bologna Italy
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32
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Reveguk ZV, Khoroshilov EV, Sharkov AV, Pomogaev VA, Buglak AA, Tarnovsky AN, Kononov AI. Exciton Absorption and Luminescence in i-Motif DNA. Sci Rep 2019; 9:15988. [PMID: 31690734 PMCID: PMC6831829 DOI: 10.1038/s41598-019-52242-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Accepted: 08/17/2019] [Indexed: 11/08/2022] Open
Abstract
We have studied the excited-state dynamics for the i-motif form of cytosine chains (dC)10, using the ultrafast fluorescence up-conversion technique. We have also calculated vertical electronic transition energies and determined the nature of the corresponding excited states in a model tetramer i-motif structure. Quantum chemical calculations of the excitation spectrum of a tetramer i-motif structure predict a significant (0.3 eV) red shift of the lowest-energy transition in the i-motif form relative to its absorption maximum, which agrees with the experimental absorption spectrum. The lowest excitonic state in i-(dC)10 is responsible for a 2 ps red-shifted emission at 370 nm observed in the decay-associated spectra obtained on the femtosecond time-scale. This delocalized (excitonic) excited state is likely a precursor to a long-lived excimer state observed in previous studies. Another fast 310 fs component at 330 nm is assigned to a monomer-like locally excited state. Both emissive states form within less than the available time resolution of the instrument (100 fs). This work contributes to the understanding of excited-state dynamics of DNA within the first few picoseconds, which is the most interesting time range with respect to unraveling the photodamage mechanism, including the formation of the most dangerous DNA lesions such as cyclobutane pyrimidine dimers.
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Affiliation(s)
- Zakhar V Reveguk
- Department of Molecular Biophysics and Polymer Physics, Saint-Petersburg State University, 199034, St. Petersburg, Russia
| | - Evgeny V Khoroshilov
- P.N. Lebedev Physical Institute, Russian Academy of Sciences, 53 Leninsky Pr., 119991, Moscow, Russia
| | - Andrey V Sharkov
- P.N. Lebedev Physical Institute, Russian Academy of Sciences, 53 Leninsky Pr., 119991, Moscow, Russia
| | - Vladimir A Pomogaev
- Department of Physics, Tomsk State University, Tomsk, 634050, Russia
- Department of Chemistry and Green-Nano Materials Research Center, College of Natural Sciences, Kyungpook National University 1370 Sankyuk-dong, Buk-gu, Daegu, 702-701, Republic of Korea
| | - Andrey A Buglak
- Department of Molecular Biophysics and Polymer Physics, Saint-Petersburg State University, 199034, St. Petersburg, Russia
| | - Alexander N Tarnovsky
- Department of Chemistry and the Center for Photochemical Sciences, Bowling Green State University, Bowling Green, OH, USA
| | - Alexei I Kononov
- Department of Molecular Biophysics and Polymer Physics, Saint-Petersburg State University, 199034, St. Petersburg, Russia.
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33
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Li XD, Gao YT, Sun YJ, Jin XY, Wang D, Liu L, Cheng L. A NaI/H2O2-Mediated Sulfenylation and Selenylation of Unprotected Uracil and Its Derivatives. Org Lett 2019; 21:6643-6647. [DOI: 10.1021/acs.orglett.9b02183] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Xue-Dong Li
- Beijing National Laboratory for Molecular Sciences (BNLMS), CAS Key Laboratory of Molecular Recognition and Function, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Yu-Ting Gao
- Beijing National Laboratory for Molecular Sciences (BNLMS), CAS Key Laboratory of Molecular Recognition and Function, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ying-Jie Sun
- Beijing National Laboratory for Molecular Sciences (BNLMS), CAS Key Laboratory of Molecular Recognition and Function, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiao-Yang Jin
- Beijing National Laboratory for Molecular Sciences (BNLMS), CAS Key Laboratory of Molecular Recognition and Function, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Dong Wang
- Beijing National Laboratory for Molecular Sciences (BNLMS), CAS Key Laboratory of Molecular Recognition and Function, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Li Liu
- Beijing National Laboratory for Molecular Sciences (BNLMS), CAS Key Laboratory of Molecular Recognition and Function, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Liang Cheng
- Beijing National Laboratory for Molecular Sciences (BNLMS), CAS Key Laboratory of Molecular Recognition and Function, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
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34
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Wang X, Yu Y, Zhou Z, Liu Y, Yang Y, Xu J, Chen J. Ultrafast Intersystem Crossing in Epigenetic DNA Nucleoside 2′-Deoxy-5-formylcytidine. J Phys Chem B 2019; 123:5782-5790. [DOI: 10.1021/acs.jpcb.9b04361] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Xueli Wang
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China
| | - Yang Yu
- Shanghai Key Laboratory of Chemical Biology, School of Pharmacy, East China University of Science and Technology, Shanghai 200237, China
| | - Zhongneng Zhou
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China
| | - Yangyi Liu
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China
| | - Youjun Yang
- Shanghai Key Laboratory of Chemical Biology, School of Pharmacy, East China University of Science and Technology, Shanghai 200237, China
| | - Jianhua Xu
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, China
| | - Jinquan Chen
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, China
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35
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Martinez-Fernandez L, Gavvala K, Sharma R, Didier P, Richert L, Segarra Martì J, Mori M, Mely Y, Improta R. Excited-State Dynamics of Thienoguanosine, an Isomorphic Highly Fluorescent Analogue of Guanosine. Chemistry 2019; 25:7375-7386. [PMID: 30882930 DOI: 10.1002/chem.201900677] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 03/15/2019] [Indexed: 12/27/2022]
Abstract
Thienoguanosine (th G) is an isomorphic analogue of guanosine with promising potentialities as fluorescent DNA label. As a free probe in protic solvents, th G exists in two tautomeric forms, identified as the H1, being the only one observed in nonprotic solvents, and H3 keto-amino tautomers. We herein investigate the photophysics of th G in solvents of different polarity, from water to dioxane, by combining time-resolved fluorescence with PCM/TD-DFT and CASSCF calculations. Fluorescence lifetimes of 14.5-20.5 and 7-13 ns were observed for the H1 and H3 tautomers, respectively, in the tested solvents. In methanol and ethanol, an additional fluorescent decay lifetime (≈3 ns) at the blue emission side (λ≈430 nm) as well as a 0.5 ns component with negative amplitude at the red edge of the spectrum, typical of an excited-state reaction, were observed. Our computational analysis explains the solvent effects observed on the tautomeric equilibrium. The main radiative and nonradiative deactivation routes have been mapped by PCM/TD-DFT calculations in solution and CASSCF in the gas phase. The most easily accessible conical intersection, involving an out-of plane motion of the sulfur atom in the five-membered ring of th G, is separated by a sizeable energy barrier (≥0.4 eV) from the minimum of the spectroscopic state, which explains the large experimental fluorescence quantum yield.
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Affiliation(s)
- Lara Martinez-Fernandez
- Departamento de Química, Facultad de Ciencias, Modúlo13, Universidad Autónoma de Madrid, Campus de Excelencia UAM-CSIC, Cantoblanco, 28049 Madrid, Spain
| | - Krishna Gavvala
- Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Université de Strasbourg, Faculté de pharmacie, 74 route du Rhin, 67401, Illkirch, France
| | - Rajhans Sharma
- Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Université de Strasbourg, Faculté de pharmacie, 74 route du Rhin, 67401, Illkirch, France
| | - Pascal Didier
- Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Université de Strasbourg, Faculté de pharmacie, 74 route du Rhin, 67401, Illkirch, France
| | - Ludovic Richert
- Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Université de Strasbourg, Faculté de pharmacie, 74 route du Rhin, 67401, Illkirch, France
| | - Javier Segarra Martì
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London, White City Campus, 80 Wood Lane, W12 0BZ, London, UK
| | - Mattia Mori
- Dipartimento di Biotecnologie, Chimica e Farmacia, Università degli Studi di Siena, 53100, Siena, Italy
| | - Yves Mely
- Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Université de Strasbourg, Faculté de pharmacie, 74 route du Rhin, 67401, Illkirch, France
| | - Roberto Improta
- Consiglio Nazionale delle Ricerche, Istituto Biostrutture e Bioimmagini, Via Mezzocannone 16, 80134, Napoli, Italy
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36
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Brister MM, Crespo-Hernández CE. Excited-State Dynamics in the RNA Nucleotide Uridine 5'-Monophosphate Investigated Using Femtosecond Broadband Transient Absorption Spectroscopy. J Phys Chem Lett 2019; 10:2156-2161. [PMID: 30995048 DOI: 10.1021/acs.jpclett.9b00492] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Damage to RNA from ultraviolet radiation induces chemical modifications to the nucleobases. Unraveling the excited states involved in these reactions is essential; however, investigations aimed at understanding the electronic-energy relaxation pathways of the RNA nucleotide uridine 5'-monophosphate (UMP) have not received enough attention. In this Letter, the excited-state dynamics of UMP is investigated in aqueous solution. Excitation at 267 nm results in a trifurcation event that leads to the simultaneous population of the vibrationally excited ground state, a long-lived 1nπ* state, and a receiver triplet state within 200 fs. The receiver state internally converts to the long-lived 3ππ* state in an ultrafast time scale. The results elucidate the electronic relaxation pathways and clarify earlier transient absorption experiments performed for uracil derivatives in solution. This mechanistic information is important because long-lived nπ* and ππ* excited states of both singlet and triplet multiplicities are thought to lead to the formation of harmful photoproducts.
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Affiliation(s)
- Matthew M Brister
- Department of Chemistry , Case Western Reserve University , 10900 Euclid Avenue , Cleveland , Ohio 44106 , United States
| | - Carlos E Crespo-Hernández
- Department of Chemistry , Case Western Reserve University , 10900 Euclid Avenue , Cleveland , Ohio 44106 , United States
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37
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Mai S, Mohamadzade A, Marquetand P, González L, Ullrich S. Simulated and Experimental Time-Resolved Photoelectron Spectra of the Intersystem Crossing Dynamics in 2-Thiouracil. Molecules 2018; 23:E2836. [PMID: 30388739 PMCID: PMC6278540 DOI: 10.3390/molecules23112836] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 10/25/2018] [Accepted: 10/26/2018] [Indexed: 11/16/2022] Open
Abstract
We report time-dependent photoelectron spectra recorded with a single-photon ionization setup and extensive simulations of the same spectra for the excited-state dynamics of 2-thiouracil (2TU) in the gas phase. We find that single-photon ionization produces very similar results as two-photon ionization, showing that the probe process does not have a strong influence on the measured dynamics. The good agreement between the single-photon ionization experiments and the simulations shows that the norms of Dyson orbitals allow for qualitatively describing the ionization probabilities of 2TU. This reasonable performance of Dyson norms is attributed to the particular electronic structure of 2TU, where all important neutral and ionic states involve similar orbital transitions and thus the shape of the Dyson orbitals do not strongly depend on the initial neutral and final ionic state. We argue that similar situations should also occur in other biologically relevant thio-nucleobases, and that the time-resolved photoelectron spectra of these bases could therefore be adequately modeled with the techniques employed here.
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Affiliation(s)
- Sebastian Mai
- Institute of Theoretical Chemistry, Faculty of Chemistry, University of Vienna, Währinger Straße 17, 1090 Vienna, Austria.
| | - Abed Mohamadzade
- Department of Physics and Astronomy, University of Georgia, Athens, GA 30602, USA.
| | - Philipp Marquetand
- Institute of Theoretical Chemistry, Faculty of Chemistry, University of Vienna, Währinger Straße 17, 1090 Vienna, Austria.
| | - Leticia González
- Institute of Theoretical Chemistry, Faculty of Chemistry, University of Vienna, Währinger Straße 17, 1090 Vienna, Austria.
| | - Susanne Ullrich
- Department of Physics and Astronomy, University of Georgia, Athens, GA 30602, USA.
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38
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Nenov A, Conti I, Borrego-Varillas R, Cerullo G, Garavelli M. Linear absorption spectra of solvated thiouracils resolved at the hybrid RASPT2/MM level. Chem Phys 2018. [DOI: 10.1016/j.chemphys.2018.07.025] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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39
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Borrego-Varillas R, Teles-Ferreira DC, Nenov A, Conti I, Ganzer L, Manzoni C, Garavelli M, Maria de Paula A, Cerullo G. Observation of the Sub-100 Femtosecond Population of a Dark State in a Thiobase Mediating Intersystem Crossing. J Am Chem Soc 2018; 140:16087-16093. [DOI: 10.1021/jacs.8b07057] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Rocío Borrego-Varillas
- IFN-CNR, Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano, Italy
| | | | - Artur Nenov
- Dipartimento di Chimica Industriale, Università degli Studi di Bologna, Viale del Risorgimento 4, I-40136 Bologna, Italy
| | - Irene Conti
- Dipartimento di Chimica Industriale, Università degli Studi di Bologna, Viale del Risorgimento 4, I-40136 Bologna, Italy
| | - Lucia Ganzer
- IFN-CNR, Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano, Italy
| | - Cristian Manzoni
- IFN-CNR, Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano, Italy
| | - Marco Garavelli
- Dipartimento di Chimica Industriale, Università degli Studi di Bologna, Viale del Risorgimento 4, I-40136 Bologna, Italy
| | - Ana Maria de Paula
- Departamento de Física, Universidade Federal de Minas Gerais, 31270-901 Belo Horizonte-MG, Brazil
| | - Giulio Cerullo
- IFN-CNR, Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano, Italy
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40
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Miyata S, Tanabe S, Isozaki T, Xu YZ, Suzuki T. Characteristics of the excited triplet states of thiolated guanosine derivatives and singlet oxygen generation. Photochem Photobiol Sci 2018; 17:1469-1476. [PMID: 30280174 DOI: 10.1039/c8pp00240a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Thioguanine is sensitive to UVA light and generates singlet molecular oxygen (1O2*) when exposed to UVA. Three thioguanosine derivatives, 2',3',5'-tri-O-acetyl-6-thioguanosine (ta6TGuo), 2',3',5'-tri-O-acetyl-8-thioguanosine (ta8TGuo), and 2',3',5'-tri-O-acetyl-6,8-dithioguanosine (taDTGuo) were explored photophysically and photochemically. Nanosecond transient absorption and time-resolved near-infrared emission measurements were carried out to investigate the characteristics of their excited triplet states in acetonitrile solution. The quantum yield of intersystem crossing (ΦISC), the intrinsic decay rate constant (k0), the quenching rate constant by 3O2 (kq) and the self-quenching rate constant (kSQ) of their triplet states were all determined. From the precise analysis of the quantum yield of 1O2* generation (ΦΔ) against the concentration of dissolved molecular oxygen, the fraction of the triplet states quenched by dissolved oxygen which gives rise to 1O2* formation (SΔ) was successfully obtained with high accuracy. The ΦΔ values at low oxygen concentrations reveal that these thioguanosines, particularly taDTGuo, can still effectively generate 1O2* at low molecular oxygen concentrations like carcinomatous microenvironments. These findings indicate that taDTGuo would perform well as a potential agent for photo-induced cancer therapies.
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Affiliation(s)
- Shoma Miyata
- Department of Chemistry and Biological Science, Aoyama Gakuin University, 5-10-1 Fuchinobe, Chuo-ku, Sagamihara, Kanagawa 252-5258, Japan.
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41
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Ashwood B, Pollum M, Crespo-Hernández CE. Photochemical and Photodynamical Properties of Sulfur-Substituted Nucleic Acid Bases. Photochem Photobiol 2018; 95:33-58. [PMID: 29978490 DOI: 10.1111/php.12975] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2018] [Accepted: 06/28/2018] [Indexed: 12/25/2022]
Abstract
Sulfur-substituted nucleobases (a.k.a., thiobases) are among the world's leading prescriptions for chemotherapy and immunosuppression. Long-term treatment with azathioprine, 6-mercaptopurine and 6-thioguanine has been correlated with the photoinduced formation of carcinomas. Establishing an in-depth understanding of the photochemical properties of these prodrugs may provide a route to overcoming these carcinogenic side effects, or, alternatively, a basis for developing effective compounds for targeted phototherapy. In this review, a broad examination is undertaken, surveying the basic photochemical properties and excited-state dynamics of sulfur-substituted analogs of the canonical DNA and RNA nucleobases. A molecular-level understanding of how sulfur substitution so remarkably perturbs the photochemical properties of the nucleobases is presented by combining experimental results with quantum-chemical calculations. Structure-property relationships demonstrate the impact of site-specific sulfur substitution on the photochemical properties, particularly on the population of the reactive triplet state. The value of fundamental photochemical investigations for driving the development of ultraviolet-A chemotherapeutics is showcased. The most promising photodynamic agents identified thus far have been investigated in various carcinoma cell lines and shown to decrease cell proliferation upon exposure to ultraviolet-A radiation. Overarching principles have been elucidated for the impact that sulfur substitution of the carbonyl oxygen has on the photochemical properties of the nucleobases.
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Affiliation(s)
- Brennan Ashwood
- Department of Chemistry, Case Western Reserve University, Cleveland, OH
| | - Marvin Pollum
- Department of Chemistry, Case Western Reserve University, Cleveland, OH
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42
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Farrell KM, Brister MM, Pittelkow M, Sølling TI, Crespo-Hernández CE. Heavy-Atom-Substituted Nucleobases in Photodynamic Applications: Substitution of Sulfur with Selenium in 6-Thioguanine Induces a Remarkable Increase in the Rate of Triplet Decay in 6-Selenoguanine. J Am Chem Soc 2018; 140:11214-11218. [DOI: 10.1021/jacs.8b07665] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Kieran M. Farrell
- Department of Chemistry, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106, United States
| | - Matthew M. Brister
- Department of Chemistry, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106, United States
| | - Michael Pittelkow
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark
| | - Theis I. Sølling
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark
| | - Carlos E. Crespo-Hernández
- Department of Chemistry, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106, United States
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43
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Wang X, Zhou Z, Tang Y, Chen J, Zhong D, Jianhua Xu. Excited State Decay Pathways of 2'-Deoxy-5-methylcytidine and Deoxycytidine Revisited in Solution: A Comprehensive Kinetic Study by Femtosecond Transient Absorption. J Phys Chem B 2018; 122:7027-7037. [PMID: 29939745 DOI: 10.1021/acs.jpcb.8b00927] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Methylated cytosine is proved to have an important role as an epigenetic signal in gene regulation and is often referred to "the fifth base of DNA". A comprehensive understanding of the electronic excited state relaxation in cytosine and its methylated derivatives is crucial for revealing UV-induced photodamage to the biological genome. Because of the existence of multiple closely lying "bright" and "dark" excited states, the decay pathways in these DNA nucleosides are the most complex and the least understood so far. In this study, femtosecond transient absorption with different excitation wavelengths (240-296 nm) was used to study the relaxation of excited electronic states of 5-methylcytosine (5mC) and 2'-deoxy-5-methylcytidine (5mdCyd) in phosphate buffered aqueous solution and in acetonitrile solution. Two distinct nonradiative decay channels were directly observed. The first one is a several picosecond internal conversion channel that involves two bright ππ* states (ππ*2 and ππ*1) when ππ*2 state is initially populated. The second channel contains the lower energy ππ*1 state and a so far experimental unidentified long-lived state which exhibits a several nanosecond lifetime. The long-lived state can only be accessed by the initially excited ππ*1 state. Inspired by this new discovery in 5mC and 5mdCyd, we revisited the decay of excited state of 2'-deoxycytidine (dCyd), revealing very similar decay pathways. Additionally, a well-known dark nOπ* state (carbonyl lone pair) with ∼30 ps lifetime is present in both decay channels in dCyd. With our detailed experimental results, we successfully reconcile the long history debate of cytosine excited state relaxation mechanism by pointing out that the reason for the complex dynamics under traditional 266 nm excitation is mixed signals from the above-mentioned two distinct decay pathways. Our findings lead to a dramatically different and new picture of electronic energy relaxation in 5mdCyd/dCyd and could help to understand photostability as well as UV-induced photodamage of these nucleotides and related DNAs.
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Affiliation(s)
- Xueli Wang
- State Key Laboratory of Precision Spectroscopy , East China Normal University , Shanghai , 200062 China
| | - Zhongneng Zhou
- State Key Laboratory of Precision Spectroscopy , East China Normal University , Shanghai , 200062 China
| | - Yuankai Tang
- State Key Laboratory of Precision Spectroscopy , East China Normal University , Shanghai , 200062 China
| | - Jinquan Chen
- State Key Laboratory of Precision Spectroscopy , East China Normal University , Shanghai , 200062 China.,Collaborative Innovation Center of Extreme Optics , Shanxi University , Taiyuan , Shanxi 030006 , China
| | - Dongping Zhong
- Department of Physics, Department of Chemistry and Biochemistry, and Programs of Biophysics, Chemical Physics, and Biochemistry , The Ohio State University , Columbus , Ohio 43210 , United States
| | - Jianhua Xu
- State Key Laboratory of Precision Spectroscopy , East China Normal University , Shanghai , 200062 China.,Collaborative Innovation Center of Extreme Optics , Shanxi University , Taiyuan , Shanxi 030006 , China
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44
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Mai S, Plasser F, Pabst M, Neese F, Köhn A, González L. Surface hopping dynamics including intersystem crossing using the algebraic diagrammatic construction method. J Chem Phys 2018; 147:184109. [PMID: 29141436 DOI: 10.1063/1.4999687] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
We report an implementation for employing the algebraic diagrammatic construction to second order [ADC(2)] ab initio electronic structure level of theory in nonadiabatic dynamics simulations in the framework of the SHARC (surface hopping including arbitrary couplings) dynamics method. The implementation is intended to enable computationally efficient, reliable, and easy-to-use nonadiabatic dynamics simulations of intersystem crossing in organic molecules. The methodology is evaluated for the 2-thiouracil molecule. It is shown that ADC(2) yields reliable excited-state energies, wave functions, and spin-orbit coupling terms for this molecule. Dynamics simulations are compared to previously reported results using high-level multi-state complete active space perturbation theory, showing favorable agreement.
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Affiliation(s)
- Sebastian Mai
- Institute of Theoretical Chemistry, Faculty of Chemistry, University of Vienna, Währinger Str. 17, 1090 Vienna, Austria
| | - Felix Plasser
- Institute of Theoretical Chemistry, Faculty of Chemistry, University of Vienna, Währinger Str. 17, 1090 Vienna, Austria
| | - Mathias Pabst
- Institute of Physical Chemistry, University of Mainz, Duesbergweg 10, D-55099 Mainz, Germany
| | - Frank Neese
- Max Planck Institute for Chemical Energy Conversion, Stiftstr. 34-36, D-45470 Mülheim an der Ruhr, Germany
| | - Andreas Köhn
- Institute of Physical Chemistry, University of Mainz, Duesbergweg 10, D-55099 Mainz, Germany
| | - Leticia González
- Institute of Theoretical Chemistry, Faculty of Chemistry, University of Vienna, Währinger Str. 17, 1090 Vienna, Austria
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45
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Pollum M, Lam M, Jockusch S, Crespo‐Hernández CE. Dithionated Nucleobases as Effective Photodynamic Agents against Human Epidermoid Carcinoma Cells. ChemMedChem 2018. [DOI: 10.1002/cmdc.201800148] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Marvin Pollum
- Department of Chemistry Case Western Reserve University Cleveland OH 44106 USA
| | - Minh Lam
- Department of Medicine Case Western Reserve University School of Medicine Cleveland OH 44106 USA
| | - Steffen Jockusch
- Department of Chemistry Columbia University New York NY 10027 USA
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46
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Photorelaxation and Photorepair Processes in Nucleic and Amino Acid Derivatives. Molecules 2017; 22:molecules22122203. [PMID: 29231852 PMCID: PMC6149726 DOI: 10.3390/molecules22122203] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Revised: 12/07/2017] [Accepted: 12/09/2017] [Indexed: 11/17/2022] Open
Abstract
Understanding the fundamental interaction between electromagnetic radiation and matter is essential for a large number of phenomena, with significance to civilization.[...].
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47
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Wang Q, Xie XY, Han J, Cui G. QM and QM/MM Studies on Excited-State Relaxation Mechanisms of Unnatural Bases in Vacuo and Base Pairs in DNA. J Phys Chem B 2017; 121:10467-10478. [DOI: 10.1021/acs.jpcb.7b09046] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Qian Wang
- Key Laboratory of Theoretical
and Computational Photochemistry, Ministry of Education, College of
Chemistry, Beijing Normal University, Beijing 100875, China
| | - Xiao-Ying Xie
- Key Laboratory of Theoretical
and Computational Photochemistry, Ministry of Education, College of
Chemistry, Beijing Normal University, Beijing 100875, China
| | - Juan Han
- Key Laboratory of Theoretical
and Computational Photochemistry, Ministry of Education, College of
Chemistry, Beijing Normal University, Beijing 100875, China
| | - Ganglong Cui
- Key Laboratory of Theoretical
and Computational Photochemistry, Ministry of Education, College of
Chemistry, Beijing Normal University, Beijing 100875, China
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48
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Koyama D, Milner MJ, Orr-Ewing AJ. Evidence for a Double Well in the First Triplet Excited State of 2-Thiouracil. J Phys Chem B 2017; 121:9274-9280. [PMID: 28895733 DOI: 10.1021/acs.jpcb.7b06917] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The computationally predicted presence of two structurally distinct minima in the first triplet excited (T1) state of 2-thiouracil (2TU) is substantiated by sub-picosecond transient vibrational absorption spectroscopy (TVAS) in deuterated acetonitrile solution. Following 300 nm ultraviolet excitation to the second singlet excited state of 2TU, a transient infrared absorption band centered at 1643 cm-1 is observed within our minimum time resolution of 0.3 ps. It is assigned either to 2TU molecules in the S1 state or to vibrationally hot T1-state molecules, with the latter assignment more consistent with recent computational and experimental studies. The 1643 cm-1 band decays with a time constant of 7.2 ± 0.8 ps, and there is corresponding growth of several further bands centered at 1234, 1410, 1424, 1443, 1511, 1626, and 1660 cm-1 which show no decline in intensity over the 1 ns time limit of our measurements. These spectral features are assigned to two different conformations of 2TU, corresponding to separate energy minima on the T1-state potential energy surface, on the basis of their extended lifetimes, computed infrared frequencies, and the observed quenching of the bands by addition of styrene. Corresponding measurements for the 4-thiouracil (4TU) isomer show sub-picosecond population of the T1 state, which vibrationally cools with a time constant of 5.2 ± 0.6 ps. However, TVAS measurements in the carbonyl stretching region do not distinguish the two computed T1-state conformers of 4TU because of the similarity of their vibrational frequencies.
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Affiliation(s)
- Daisuke Koyama
- School of Chemistry, University of Bristol , Cantock's Close, Bristol BS8 1TS, U.K
| | - Matthew J Milner
- School of Chemistry, University of Bristol , Cantock's Close, Bristol BS8 1TS, U.K
| | - Andrew J Orr-Ewing
- School of Chemistry, University of Bristol , Cantock's Close, Bristol BS8 1TS, U.K
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49
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Ashwood B, Ortiz-Rodríguez LA, Crespo-Hernández CE. Excited-State Dynamics in O 6-Methylguanosine: Impact of O 6-Methylation on the Relaxation Mechanism of Guanine Monomers. J Phys Chem Lett 2017; 8:4380-4385. [PMID: 28850232 DOI: 10.1021/acs.jpclett.7b02090] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Absorption of ultraviolet radiation by DNA bases results in ultrafast internal conversion to the ground state, which minimizes photodamage. However, exogenous and endogenous alkylating agents present in the cellular environment can methylate the nucleobases in DNA. In particular, methylation of guanosine at the O6 position in DNA leads to the formation of the O6-methylguanosine adduct, which may alter the photostability of DNA. This contribution demonstrates that O6-methylation of guanosine red shifts its ground-state absorption spectrum and slows down the rate of internal conversion to the ground state by ∼40-fold in aqueous solution. The 40-fold decrease in the rate of excited-state decay increases the probability of photodamage within cellular DNA. It is proposed that the longer decay lifetime corresponds to relaxation of the excited-state population in O6-methylguanosine along a C6-puckered reaction coordinate in the 1ππ*(La) potential energy surface that runs parallel to an ultrafast internal conversion pathway along a C2-puckered coordinate.
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Affiliation(s)
- Brennan Ashwood
- Department of Chemistry and Center for Chemical Dynamics, Case Western Reserve University , Cleveland, Ohio 44106, United States
| | - Luis A Ortiz-Rodríguez
- Department of Chemistry and Center for Chemical Dynamics, Case Western Reserve University , Cleveland, Ohio 44106, United States
| | - Carlos E Crespo-Hernández
- Department of Chemistry and Center for Chemical Dynamics, Case Western Reserve University , Cleveland, Ohio 44106, United States
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50
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Bhattacharyya K, Datta A. Visible-Light-Mediated Excited State Relaxation in Semi-Synthetic Genetic Alphabet: d5SICS and dNaM. Chemistry 2017; 23:11494-11498. [PMID: 28675549 DOI: 10.1002/chem.201702583] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Indexed: 12/17/2022]
Abstract
The excited state dynamics of an unnatural base pair (UBP) d5SICS/dNaM were investigated by accurate ab-initio calculations. Time-dependent density functional and high-level multireference calculations (MS-CASPT2) were performed to elucidate the excitation of this UBP and its excited state relaxation mechanism. After excitation to the bright state S2 (ππ*), it decays to the S1 state and then undergoes efficient intersystem crossing to the triplet manifold. The presence of sulfur atom in d5SICS leads to strong spin-orbit coupling (SOC) and a small energy gap that facilitates intersystem crossing from S1 (ns π*) to T2 (ππ*) followed by internal conversion to T1 state. Similarly in dNaM, the deactivation pathway follows analogous trends. CASPT2 calculations suggest that the S1 (ππ*) state is a dark state below the accessible S2 (ππ*) bright state. During the ultrafast deactivation, it exhibits bond length inversion. From S1 state, significant SOC leads the population transfer to T3 due to a smaller energy gap. Henceforth, fast internal conversion occurs from T3 to T2 followed by T1 . From time-dependent trajectory surface hopping dynamics, it is found that excited state relaxation occurs on a sub-picosecond timescale in d5SICS and dNaM. Our findings strongly suggest that there is enough energy available in triplet state of UBP to generate reactive oxygen species and induce phototoxicity with respect to cellular DNA.
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Affiliation(s)
- Kalishankar Bhattacharyya
- Department of Spectroscopy, Indian Association for the Cultivation of Science, 2A and 2B Raja S. C. Mullick Road, Jadavpur, 700032, Kolkata, West Bengal, India
| | - Ayan Datta
- Department of Spectroscopy, Indian Association for the Cultivation of Science, 2A and 2B Raja S. C. Mullick Road, Jadavpur, 700032, Kolkata, West Bengal, India
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