78 results on '"Antonio Francés-Monerris"'
Search Results
2. Theoretical Study on the Photo-Oxidation and Photoreduction of an Azetidine Derivative as a Model of DNA Repair
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Miriam Navarrete-Miguel, Antonio Francés-Monerris, Miguel A. Miranda, Virginie Lhiaubet-Vallet, and Daniel Roca-Sanjuán
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azetidine ,DNA repair ,electron transfer ,density functional theory ,photochemistry ,ring opening ,Organic chemistry ,QD241-441 - Abstract
Photocycloreversion plays a central role in the study of the repair of DNA lesions, reverting them into the original pyrimidine nucleobases. Particularly, among the proposed mechanisms for the repair of DNA (6-4) photoproducts by photolyases, it has been suggested that it takes place through an intermediate characterized by a four-membered heterocyclic oxetane or azetidine ring, whose opening requires the reduction of the fused nucleobases. The specific role of this electron transfer step and its impact on the ring opening energetics remain to be understood. These processes are studied herein by means of quantum-chemical calculations on the two azetidine stereoisomers obtained from photocycloaddition between 6-azauracil and cyclohexene. First, we analyze the efficiency of the electron-transfer processes by computing the redox properties of the azetidine isomers as well as those of a series of aromatic photosensitizers acting as photoreductants and photo-oxidants. We find certain stereodifferentiation favoring oxidation of the cis-isomer, in agreement with previous experimental data. Second, we determine the reaction profiles of the ring-opening mechanism of the cationic, neutral, and anionic systems and assess their feasibility based on their energy barrier heights and the stability of the reactants and products. Results show that oxidation largely decreases the ring-opening energy barrier for both stereoisomers, even though the process is forecast as too slow to be competitive. Conversely, one-electron reduction dramatically facilitates the ring opening of the azetidine heterocycle. Considering the overall quantum-chemistry findings, N,N-dimethylaniline is proposed as an efficient photosensitizer to trigger the photoinduced cycloreversion of the DNA lesion model.
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- 2021
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3. Towards Iron(II) Complexes with Octahedral Geometry: Synthesis, Structure and Photophysical Properties
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Mohamed Darari, Antonio Francés-Monerris, Bogdan Marekha, Abdelatif Doudouh, Emmanuel Wenger, Antonio Monari, Stefan Haacke, and Philippe C. Gros
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iron (II) complexes ,octahedral geometry ,excited states dynamics ,density functional theory ,time-resolved spectroscopy ,Organic chemistry ,QD241-441 - Abstract
The control of ligand-field splitting in iron (II) complexes is critical to slow down the metal-to-ligand charge transfer (MLCT)-excited states deactivation pathways. The gap between the metal-centered states is maximal when the coordination sphere of the complex approaches an ideal octahedral geometry. Two new iron(II) complexes (C1 and C2), prepared from pyridylNHC and pyridylquinoline type ligands, respectively, have a near-perfect octahedral coordination of the metal. The photophysics of the complexes have been further investigated by means of ultrafast spectroscopy and TD-DFT modeling. For C1, it is shown that—despite the geometrical improvement—the excited state deactivation is faster than for the parent pseudo-octahedral C0 complex. This unexpected result is due to the increased ligand flexibility in C1 that lowers the energetic barrier for the relaxation of 3MLCT into the 3MC state. For C2, the effect of the increased ligand field is not strong enough to close the prominent deactivation channel into the metal-centered quintet state, as for other Fe-polypyridine complexes.
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- 2020
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4. Iron’s Wake: The Performance of Quantum Mechanical-Derived Versus General-Purpose Force Fields Tested on a Luminescent Iron Complex
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Valentin Diez-Cabanes, Giacomo Prampolini, Antonio Francés-Monerris, Antonio Monari, and Mariachiara Pastore
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iron complex ,chemical environment ,force field molecular dynamics ,time-dependent density functional theory ,Organic chemistry ,QD241-441 - Abstract
Recently synthetized iron complexes have achieved long-lived excited states and stabilities which are comparable, or even superior, to their ruthenium analogues, thus representing an eco-friendly and cheaper alternative to those materials based on rare metals. Most of computational tools which could help unravel the origin of this large efficiency rely on ab-initio methods which are not able, however, to capture the nanosecond time scale underlying these photophysical processes and the influence of their realistic environment. Therefore, it exists an urgent need of developing new low-cost, but still accurate enough, computational methodologies capable to deal with the steady-state and transient spectroscopy of transition metal complexes in solution. Following this idea, here we focus on the comparison between general-purpose transferable force-fields (FFs), directly available from existing databases, and specific quantum mechanical derived FFs (QMD-FFs), obtained in this work through the Joyce procedure. We have chosen a recently reported FeIII complex with nanosecond excited-state lifetime as a representative case. Our molecular dynamics (MD) simulations demonstrated that the QMD-FF nicely reproduces the structure and the dynamics of the complex and its chemical environment within the same precision as higher cost QM methods, whereas general-purpose FFs failed in this purpose. Although in this particular case the chemical environment plays a minor role on the photo physics of this system, these results highlight the potential of QMD-FFs to rationalize photophysical phenomena provided an accurate QM method to derive its parameters is chosen.
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- 2020
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5. NHC-Based Iron Sensitizers for DSSCs
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Thibaut Duchanois, Li Liu, Mariachiara Pastore, Antonio Monari, Cristina Cebrián, Yann Trolez, Mohamed Darari, Kevin Magra, Antonio Francés-Monerris, Edoardo Domenichini, Marc Beley, Xavier Assfeld, Stefan Haacke, and Philippe C. Gros
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iron complexes ,NHC ligands ,excited states ,photophysics ,Inorganic chemistry ,QD146-197 - Abstract
Nanostructured dye-sensitized solar cells (DSSCs) are promising photovoltaic devices because of their low cost and transparency. Ruthenium polypyridine complexes have long been considered as lead sensitizers for DSSCs, allowing them to reach up to 11% conversion efficiency. However, ruthenium suffers from serious drawbacks potentially limiting its widespread applicability, mainly related to its potential toxicity and scarcity. This has motivated continuous research efforts to develop valuable alternatives from cheap earth-abundant metals, and among them, iron is particularly attractive. Making iron complexes applicable in DSSCs is highly challenging due to an ultrafast deactivation of the metal–ligand charge-transfer (MLCT) states into metal-centered (MC) states, leading to inefficient injection into TiO2. In this review, we present our latest developments in the field using Fe(II)-based photosensitizers bearing N-heterocyclic carbene (NHC) ligands, and their use in DSSCs. Special attention is paid to synthesis, photophysical, electrochemical, and computational characterization.
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- 2018
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6. Assessment of the Potential Energy Hypersurfaces in Thymine within Multiconfigurational Theory: CASSCF vs. CASPT2
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Javier Segarra-Martí, Antonio Francés-Monerris, Daniel Roca-Sanjuán, and Manuela Merchán
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CASSCF/CASPT2 ,photochemistry ,DNA ,thymine ,photostability ,Organic chemistry ,QD241-441 - Abstract
The present study provides new insights into the topography of the potential energy hypersurfaces (PEHs) of the thymine nucleobase in order to rationalize its main ultrafast photochemical decay paths by employing two methodologies based on the complete active space self-consistent field (CASSCF) and the complete active space second-order perturbation theory (CASPT2) methods: (i) CASSCF optimized structures and energies corrected with the CASPT2 method at the CASSCF geometries and (ii) CASPT2 optimized geometries and energies. A direct comparison between these strategies is drawn, yielding qualitatively similar results within a static framework. A number of analyses are performed to assess the accuracy of these different computational strategies under study based on a variety of numerical thresholds and optimization methods. Several basis sets and active spaces have also been calibrated to understand to what extent they can influence the resulting geometries and subsequent interpretation of the photochemical decay channels. The study shows small discrepancies between CASSCF and CASPT2 PEHs, displaying a shallow planar or twisted 1(ππ*) minimum, respectively, and thus featuring a qualitatively similar scenario for supporting the ultrafast bi-exponential deactivation registered in thymine upon UV-light exposure. A deeper knowledge of the PEHs at different levels of theory provides useful insight into its correct characterization and subsequent interpretation of the experimental observations. The discrepancies displayed by the different methods studied here are then discussed and framed within their potential consequences in on-the-fly non-adiabatic molecular dynamics simulations, where qualitatively diverse outcomes are expected.
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- 2016
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7. Spatial and Temporal Resolution of the Oxygen-Independent Photoinduced DNA Interstrand Cross-Linking by a Nitroimidazole Derivative.
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Abdelazim M. A. Abdelgawwad, Antonio Monari, Iñaki Tuñón, and Antonio Francés-Monerris
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- 2022
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8. Substituent-Induced Control of fac/mer Isomerism in Azine-NHC Fe(II) Complexes
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Ulises Carrillo, Antonio Francés-Monerris, Anil Reddy Marri, Cristina Cebrián, and Philippe C. Gros
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Cultural Studies ,History ,Literature and Literary Theory - Published
- 2022
9. Spatial and Temporal Resolution of the Oxygen-Independent Photoinduced DNA Interstrand Cross-Linking by a Nitroimidazole Derivative
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Antonio Francés-Monerris, Iñaki Tuñón, Abdelazim Abdelgawwad, and Antonio Monari
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Oxygen ,Photosensitizing Agents ,Nitroimidazoles ,General Chemical Engineering ,DNA ,General Chemistry ,Library and Information Sciences ,Base Pairing ,Computer Science Applications - Abstract
DNA damage is ubiquitous in nature and is at the basis of emergent treatments such as photodynamic therapy, which is based on the activation of highly oxidative reactive oxygen species by photosensitizing O
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- 2022
10. Oxidation-sensitive cysteines drive IL-38 amyloid formation
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Alejandro Diaz-Barreiro, Gea Cereghetti, Jenna Tonacini, Dominique Talabot-Ayer, Sylvie Kieffer-Jaquinod, Arnaud Huard, Christopher Swale, Yohann Couté, Matthias Peter, Antonio Francés-Monerris, and Gaby Palmer
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Cytokines of the interleukin (IL)-1 family are widely expressed in epithelial surfaces, including the epidermis, where they play a key role in the maintenance of barrier integrity and host defense. A recent report associated the IL-1 family member IL-33 with stress granules (SGs) in epithelial cells. Formation of SGs is promoted by the aggregation of proteins harboring low complexity regions (LCRs). In this study, using computational analyses, we predicted the presence of LCRs in six of the eleven IL-1 family members. Among these, IL-38 contained a long LCR and localized to Ras GTPase-activating protein binding protein 1 (G3BP1) positive SGs, as well as to G3BP1 negative intracellular protein condensates in keratinocytes exposed to oxidative stress (OS). In addition, we identified two highly aggregation-prone amyloid core (AC) motifs in the IL-38 LCR and detected the formation of amyloid IL-38 aggregates in response to OS in cells andin vitro. Disulfide bond mapping,in silicomodelling and the analysis of specific cysteine mutants supported a model in which specific oxidation-sensitive cysteines act as redox switches to modify the conformation of IL-38 and thus the surface exposure of its ACs, shuttling it from a soluble state into biomolecular condensates. Finally, the presence of IL-38 granules in human epidermal layers highly exposed to environmental OS suggests that oxidation-induced formation of amyloid aggregates, as a previously unrecognized intrinsic biological property of IL-38, may be physiologically relevant at this epithelial barrier.
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- 2023
11. Contributors
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Stefano Battaglia, Yi-Chun Chu, Stefano Corni, Juliana Cuéllar-Zuquin, Piotr de Silva, Leonardo Evaristo de Sousa, Adrian L. Dempwolff, Valentin Diez-Cabanes, Pavlo O. Dral, Andreas Dreuw, Simona Fantacci, Daniele Fazzi, Ignacio Fdez. Galván, Antonio Francés-Monerris, Jacopo Fregoni, Luis Manuel Frutos, Cristina García-Iriepa, Angelo Giussani, John M. Herbert, Alejandro Jodra, Waldemar Kaiser, M.G. Khrenova, Jingbai Li, Roland Lindh, Steven A. Lopez, Raúl Losantos, Zhao-Xue Luan, Marco Marazzi, Lara Martínez-Fernández, Edoardo Mosconi, Isabelle Navizet, Martina Nucci, Mariachiara Pastore, Daniel Roca-Sanjuán, Diego Sampedro, A.P. Savitsky, Javier Segarra-Martí, Morgane Vacher, Xin-Ping Wu, Ming-Yu Yang, Lin Zhao, and Zi-Jian Zhou
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- 2023
12. DNA photostability
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Lara Martínez-Fernández and Antonio Francés-Monerris
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- 2023
13. Photochemistry of HOSO2 and SO3 and Implications for the Production of Sulfuric Acid
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Joseph S. Francisco, Carlos A. Cuevas, Daniel Roca-Sanjuán, Tarek Trabelsi, Javier Carmona-García, Antonio Francés-Monerris, Alfonso Saiz-Lopez, Fundación Caixa Galicia, Ministerio de Ciencia e Innovación (España), Generalitat Valenciana, and Universidad de Valencia
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Radical ,Photodissociation ,Context (language use) ,Sulfuric acid ,General Chemistry ,Photochemistry ,Biochemistry ,Catalysis ,chemistry.chemical_compound ,Colloid and Surface Chemistry ,chemistry ,Sulfur trioxide ,Reactivity (chemistry) ,Acid rain ,Sulfur dioxide - Abstract
9 pags., 5 figs., Sulfur trioxide (SO3) and the hydroxysulfonyl radical (HOSO2) are two key intermediates in the production of sulfuric acid (H2SO4) on Earth's atmosphere, one of the major components of acid rain. Here, the photochemical properties of these species are determined by means of high-level quantum chemical methodologies, and the potential impact of their light-induced reactivity is assessed within the context of the conventional acid rain generation mechanism. Results reveal that the photodissociation of HOSO2 occurs primarily in the stratosphere through the ejection of hydroxyl radicals (•OH) and sulfur dioxide (SO2). This may decrease the production rate of H2SO4 in atmospheric regions with low O2 concentration. In contrast, the photostability of SO3 under stratospheric conditions suggests that its removal efficiency, still poorly understood, is key to assess the H2SO4 formation in the upper atmosphere., The project that gave rise to these results received the support of a fellowship for J.C.-G. from “la Caixa” Foundation (ID 100010434); the fellowship code is LCF/BQ/DR20/11790027. This work was supported by the Spanish “Ministerio de Ciencia e Innovación (MICINN)” (Project ref. CTQ2017-87054-C2-2-P) and Unit of Excellence María de Maeztu CEX2019-000919-M). D.R.-S. is grateful to the Spanish MICINN for the “Ramón y Cajal” grant (ref. RYC2015-19234). A.F.-M. is grateful to the Generalitat Valenciana and the European Social Fund for the postdoctoral contract APOSTD/2019/149 and the project GV/2020/226, and to the MICINN for the “Juan de la Cierva” contract IJC2019-039297-I. Computations have been partially conducted at the local QCEXVAL cluster and the Tirant v3 supercluster (Servei d’Informatica of the University of Valencia).
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- 2021
14. Light‐Induced On/Off Switching of the Surfactant Character of the o ‐Cobaltabis(dicarbollide) Anion with No Covalent Bond Alteration
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Francesc Teixidor, Clara Viñas, Antonio Francés-Monerris, Jewel Ann Maria Xavier, Abdelazim M. A. Abdelgawwad, Daniel Roca-Sanjuán, Generalitat Valenciana, Generalitat de Catalunya, Ministerio de Ciencia, Innovación y Universidades (España), European Commission, Xavier, Jewel Ann Maria [0000-0002-5925-5900], Roca-Sanjuán, Daniel [0000-0001-6495-2770], Viñas, Clara [0000-0001-5000-0277], Teixidor, Francesc [0000-0002-3010-2417], Francés Monerris, Antonio [0000-0001-8232-4989], Xavier, Jewel Ann Maria, Roca-Sanjuán, Daniel, Viñas, Clara, Teixidor, Francesc, and Francés Monerris, Antonio
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Photodynamics ,Aqueous solution ,Chemistry ,General Medicine ,General Chemistry ,Photochemistry ,Fluorescence ,Quantum chemistry ,Micelle ,Catalysis ,Thermal decay ,Covalent bond ,Carborane ,Ground state ,Conformational isomerism - Abstract
Cobaltabis(dicarbollide) anion ([o-COSAN]- ) is a well-known metallacarborane with multiple applications in a variety of fields. In aqueous solution, the cisoid rotamer is the most stable disposition in the ground state. The present work provides theoretical evidence on the possibility to photoinduce the rotation from the cisoid to the transoid rotamer, a conversion that can be reverted when the ground state is repopulated. The non-radiative decay mechanisms proposed in this work are coherent with the lack of fluorescence observed in 3D fluorescence mapping experiments performed on [o-COSAN]- and its derivatives. This phenomenon induced by light has the potential to destruct the vesicles and micelles cisoid [o-COSAN]- typically forms in aqueous solution, which could lead to promising applications, particularly in the field of nanomedicine., This work was supported by the Generalitat Valenciana (GV, project GV/2020/226), Generalitat de Catalunya (2017 SGR 1720), and the Spanish Ministerio de Ciencia e Innovación (MICINN, projects CTQ2017-87054-C2-2–304-P and PID2019-106832RB-I00). A.M.A.A. is grateful to the Erasmus+ Programme of the European Comission for his Erasmus Mundus TCCM scholarship. A.F.-M. is grateful to the GV and the European Social Fund for the postdoctoral contract APOSTD/2019/149 and to the MICINN for the Juan de la Cierva contract IJC2019-039297-I. D.R.-S. is grateful to the MICINN for the “Ramón y Cajal” grant (RYC-2015–19234). “Severo Ochoa” Program for Centers of Excellence in R&D 234 (SEV-2015-0496) is appreciated. J. A. M. Xavier acknowledges DOC-FAM programme under the Marie Sklodowska-Curie grant agreement No. 754397 and is enrolled in the PhD program of the UAB. Computations have been conducted at the local QCEXVAL and the LluisVives and Tirant III clusters of the Servei d'Informàtica (University of Valencia). We thank Dr. Jordi Faraudo (ICMAB-CSIC) for the scientific discussions., With funding from the Spanish government through the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000917-S).
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- 2021
15. A multiscale free energy method reveals an unprecedented photoactivation of a bimetallic Os(II)-Pt(II) dual anticancer agent
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Antonio Francés-Monerris and Marta Erminia Alberto
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Photochemotherapy ,Coordination Complexes ,Photochemistry ,Transition Elements ,General Physics and Astronomy ,Antineoplastic Agents ,Physical and Theoretical Chemistry - Abstract
The photoreactivity of relatively large transition metal complexes is often limited to the description of the static potential energy surfaces of the involved electronic states. While useful to grasp some physical grounds of the photoinduced molecular responses, this approach does not statistically sample the multiple molecular degrees of freedom of the systems under investigation, which grow significantly if we consider the explicit coupling with the environment, and does not consider dynamic effects. The problem is even more complex if the reactivity takes place in the excited state. The present work uses state-of-the-art multiscale QM/MM dynamics to describe the photoactivation of a Pt(II)-unit of an
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- 2022
16. Photochemistry and Non-adiabatic Photodynamics of the HOSO Radical
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Joseph S. Francisco, Tarek Trabelsi, Antonio Francés-Monerris, Alfonso Saiz-Lopez, Daniel Roca-Sanjuán, Javier Carmona-García, Carlos A. Cuevas, Fundación Caixa Galicia, Generalitat Valenciana, Ministerio de Ciencia, Innovación y Universidades (España), and Universidad de Valencia
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Ozone ,business.industry ,Chemistry ,General Chemistry ,Photochemistry ,Biochemistry ,Quantum chemistry ,Catalysis ,Atmosphere ,chemistry.chemical_compound ,Colloid and Surface Chemistry ,Reactivity (chemistry) ,Geoengineering ,business ,Adiabatic process ,Stratosphere - Abstract
6 pags., 2 figs., Hydroxysulfinyl radical (HOSO) is important due to its involvement in climate geoengineering upon SO2 injection and generation of the highly hygroscopic H2SO4. Its photochemical behavior in the upper atmosphere is, however, uncertain. Here we present the ultraviolet-visible photochemistry and photodynamics of this species by simulating the atmospheric conditions with high-level quantum chemistry methods. Photocleavage to HO + SO arises as the major solar-induced channel, with a minor contribution of H + SO2 photoproducts. The efficient generation of SO is relevant due to its reactivity with O3 and the consequent depletion of ozone in the stratosphere., The project that gave rise to these results received the support of a fellowship for J.C.-G. from “La Caixa” Foundation (ID 100010434); the fellowship code is LCF/BQ/DR20/ 11790027. A.F.-M. is grateful to the Generalitat Valenciana and the European Social Fund for the postdoctoral contract APOSTD/2019/149 and the project GV/2020/226. This work was supported by the Spanish “Ministerio de Ciencia e Innovación (MICINN)” (Project ref CTQ2017-87054-C2-2-P and Unit of Excellence María de Maeztu CEX2019-000919- M). D.R.-S. is grateful to the Spanish MICINN for the “Ramón y Cajal” grant (ref RYC-2015-19234). Computations have been partially conducted at the local QCEXVAL cluster and the Tirant v3 supercluster (University of Valencia).
- Published
- 2021
17. Intraligand Excited States Turn a Ruthenium Oligothiophene Complex into a Light-Triggered Ubertoxin with Anticancer Effects in Extreme Hypoxia
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John A. Roque III, Houston D. Cole, Patrick C. Barrett, Liubov M. Lifshits, Rachel O. Hodges, Susy Kim, Gagan Deep, Antonio Francés-Monerris, Marta E. Alberto, Colin G. Cameron, and Sherri A. McFarland
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Colloid and Surface Chemistry ,Photosensitizing Agents ,Photochemotherapy ,Humans ,General Chemistry ,Hypoxia ,Biochemistry ,Catalysis ,Article ,Ruthenium ,Phenanthrolines - Abstract
Ru(II) complexes that undergo photosubstitution reactions from triplet metal-centered ((3)MC) excited states are of interest in photochemotherapy (PCT) for their potential to produce cytotoxic effects in hypoxia. Dual-action systems that incorporate this stoichiometric mode to complement the oxygen-dependent photosensitization pathways that define photodynamic therapy (PDT) are poised to maintain antitumor activity regardless of oxygenation status. Herein, we examine the way in which these two pathways influence photocytotoxicity in normoxia and in hypoxia using the [Ru(dmp)(2)(IP-nT)](2+) series (where dmp=2,9-dimethyl-1,10-phenanthroline and IP-nT=imidazo[4,5-f][1,10]phenanthroline tethered to n=0–4 thiophene rings) to switch the dominant excited state from the metal-based (3)MC state in the case of Ru-phen–Ru-1T to ligand-based (3)ILCT state for Ru-3T and Ru-4T. Ru-phen–Ru-1T, having dominant (3)MC states and the largest photosubstitution quantum yields, were inactive in both normoxia and hypoxia. Ru-3T and Ru-4T, with dominant (3)IL/(3)ILCT states and long triplet lifetimes (τ(TA)=20–25 μs), had the poorest photosubstitution quantum yields yet were extremely active. In the best instances, Ru-4T exhibited attomolar phototoxicity toward SKMEL28 cells in normoxia and picomolar in hypoxia, with PI values in normoxia of 10(5)–10(12) and 10(3)–10(6) in hypoxia. While maximizing excited state deactivation through photodissociative (3)MC states did not result in bonafide dual-action PDT/PCT agents, the study has produced the most potent photosensitizer we know of to date. The extraordinary photosensitizing capacity of Ru-3T and Ru-4T may stem from a combination of very efficient (1)O(2) production and possibly complementary Type I pathways via (3)ILCT excited states.
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- 2022
18. Trans-to-cis photoisomerization of cyclocurcumin in different environments rationalized by computational photochemistry
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Maxime Mourer, Marco Marazzi, Antonio Francés-Monerris, Andreea Pasc, Antonio Monari, University of Alcalá / Department of Analytical Chemistry, Physical-Chemistry and Chemical Engineering, Universidad de Alcalá - University of Alcalá (UAH), Laboratoire de Physique et Chimie Théoriques (LPCT), Institut de Chimie du CNRS (INC)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Facultat de Fisica [València] (UV), Universitat de València (UV), and Laboratoire Lorrain de Chimie Moléculaire (L2CM)
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Photoswitch ,Photoisomerization ,Chemistry ,General Physics and Astronomy ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Photochemistry ,01 natural sciences ,Fluorescence ,0104 chemical sciences ,Excited state ,[CHIM]Chemical Sciences ,Molecule ,Physical and Theoretical Chemistry ,Solvent effects ,0210 nano-technology ,Ground state ,Cis–trans isomerism - Abstract
International audience; Cyclocurcumin is a turmeric component that attracted much less attention compared to the well known curcumin. In spite of the less deep charcaterization of its properties, cyclocurcumin has shown promising anticancer effects when used in combination with curcumin. Especially, due to its peculiar molecular structure, cyclocurcumin can be regarded as an almost ideal photoswitch, whose capabilities can also be exploited for relevant biological applications. Here, by means of state-of-the-art computational methods for electronic excited-state calculations (TD-DFT, MS-CASPT2, XMS-CASPT2) we analyze in detail the absorption and photoisomerization pathways leading from the more stable trans isomer to the cis one. The different molecular surroundings, taken into account by means of electrostatic solvent effect and compared with available experimental data, have been found to be critical in describing the fate of irradiated cyclocurcumin: while in non-polar environments an excited state barrier prevents photoisomerization and favours fluorescence, in polar solvents an almost barrierless path results in a strikingly decrease of fluorescence, opening the way toward a crossing region with the ground state and thus funneling the photoproduction of the cis isomer.
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- 2020
19. Quantum chemistry of the excited state: advances in 2020–2021
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Juliana Cuéllar-Zuquin, Javier Carmona-García, Miriam Navarrete-Miguel, Luis Cerdán, Antonio Francés-Monerris, Angelo Giussani, Javier Segarra-Martí, and Daniel Roca-Sanjuán
- Published
- 2022
20. Triplet stabilization for enhanced drug photorelease from sunscreen-based photocages
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Antonio Monari, Virginie Lhiaubet-Vallet, Mauricio Lineros-Rosa, M. Consuelo Cuquerella, Antonio Francés-Monerris, Miguel A. Miranda, Ministerio de Ciencia e Innovación (España), and Generalitat Valenciana
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Drug ,Ultraviolet Rays ,media_common.quotation_subject ,UV filter ,010402 general chemistry ,Photochemistry ,01 natural sciences ,Biochemistry ,chemistry.chemical_compound ,QUIMICA ORGANICA ,Hexanes ,Prodrugs ,Physical and Theoretical Chemistry ,media_common ,Propiophenones ,Quenching (fluorescence) ,Photolysis ,Photosensitizing Agents ,Ethanol ,010405 organic chemistry ,Organic Chemistry ,Anti-Inflammatory Agents, Non-Steroidal ,Acceptor ,0104 chemical sciences ,Hexane ,Solvent ,chemistry ,Models, Chemical ,Ketoprofen ,Excited state ,Solvents ,Avobenzone ,Sunscreening Agents - Abstract
[EN] Recently, sunscreen-based drug photocages have been introduced to provide UV protection to photoactive drugs, thus increasing their photosafety. Here, combined experimental and theoretical studies performed on a photocage based on the commercial UVA filter avobenzone (AB) and on the photosensitizing non-steroidal anti-inflammatory drug ketoprofen (KP) are presented unveiling the photophysical processes responsible for the light-triggered release. Particular attention is paid to solvent stabilization of the drug and UV filter excited states, respectively, which leads to a switching between the triplet excited state energies of the AB and KP units. Most notably, we show that the stabilization of the AB triplet excited state in ethanol solution is the key requirement for an efficient photouncaging. By contrast, in apolar solvents, in particular hexane, KP has the lowest triplet excited state, hence acting as an energy acceptor quenching the AB triplet manifold, thus inhibiting the desired photoreaction., Support from the Universite de Lorraine, CNRS, regional (Prometeo/2017/075) and Spanish Government (PGC2018-096684-B-I00, CTQ2017-87054-C2-2-P) is kindly acknowledged. A. F.-M. is grateful to Generalitat Valenciana and the European Social Fund (postdoctoral contract APOSTD/2019/149 and project GV/2020/226) for financial support. M. L.-R. acknowledges the Universitat Politecnica de Valencia for the FPI grant. All calculations have been performed on the local LPCT computer center and on the Explor regional center in the framework of the project "Dancing under the light".
- Published
- 2021
21. Bidentate pyridyl‐NHC ligands: synthesis, ground and excited state properties of their iron(II) complexes and role of the fac/mer isomerism
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Stefan Haacke, Antonio Francés-Monerris, Philippe C. Gros, Antonio Monari, Kévin Magra, Cristina Cebrian, Institut de Chimie Moléculaire et des Matériaux d'Orsay (ICMMO), Institut de Chimie du CNRS (INC)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Facultat de Fisica [València] (UV), Universitat de València (UV), Laboratoire Lorrain de Chimie Moléculaire (L2CM), Institut de Chimie du CNRS (INC)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Interfaces, Traitements, Organisation et Dynamique des Systèmes (ITODYS (UMR_7086)), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), Université de Strasbourg (UNISTRA)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Laboratoire de Physique et Chimie Théoriques (LPCT), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et Nanosciences Grand-Est (MNGE), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), A.F.-M.is grateful to Generalitat Valenciana and the European Social Fund (project GV/2020/226) and the Ministerio de Ciencia e Innovación (projectCTQ2017-87054-C2-2-P and Juande la Cierva contract IJC2019-039297-I) for financial support., ANR-16-CE07-0013,PhotIron,Design de complexes de fer à propriétés photophysiques applicables(2016), ANR-10-IDEX-0002,UNISTRA,Par-delà les frontières, l'Université de Strasbourg(2010), ANR-20-SFRI-0012,STRAT'US,Façonner les talents en formation et en recherche à l'Université de Strasbourg(2020), ANR-17-EURE-0024,QMAT,Quantum Science and Nanomaterials(2017), European Project: Synergie LO0024898,FEDER,FIRELIGHT(2018), GROS, PHILIPPE C., Design de complexes de fer à propriétés photophysiques applicables - - PhotIron2016 - ANR-16-CE07-0013 - AAPG2016 - VALID, Initiative d'excellence - Par-delà les frontières, l'Université de Strasbourg - - UNISTRA2010 - ANR-10-IDEX-0002 - IDEX - VALID, Façonner les talents en formation et en recherche à l'Université de Strasbourg - - STRAT'US2020 - ANR-20-SFRI-0012 - SFRI - VALID, Quantum Science and Nanomaterials - - QMAT2017 - ANR-17-EURE-0024 - EURE - VALID, and FireLight : Photo-bio-active molecules and nanoparticles - FIRELIGHT - - FEDER2018-01-01 - 2022-12-31 - Synergie LO0024898 - VALID
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Computational chemistry ,Denticity ,010405 organic chemistry ,Chemistry ,Iron ,Bidentate ligands ,[CHIM.COOR] Chemical Sciences/Coordination chemistry ,010402 general chemistry ,01 natural sciences ,Medicinal chemistry ,0104 chemical sciences ,Inorganic Chemistry ,[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry ,[CHIM.THEO] Chemical Sciences/Theoretical and/or physical chemistry ,Excited state ,[CHIM.COOR]Chemical Sciences/Coordination chemistry ,Carbene ligands ,Ultrafast spectroscopy - Abstract
International audience; Iron complexes are promising candidates for the development of sustainable molecular photoactive materials as an alternative to those based on precious metals such as Ir, Pt or Ru. These compounds possess metal-ligand charge transfer (MLCT) transitions potentially of high interest for energy conversion or photocatalysis applications if the ultrafast deactivation via lower-lying metal-centred (MC) states can be impeded. Following an introduction describing the main design strategies used so far to increase the MLCT lifetimes, we review some of our latest contributions to the field regarding bidentate Fe(II) complexes comprising N-heterocyclic carbene ligands. The discussion covers all aspects from their synthesis to their characterization via photophysical, electrochemical and computational techniques. The impact of bidentate coordination together with the configuration (facial and meridional isomers) is analysed, finally highlighting the current challenges in this promising area.
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- 2021
22. Photochemistry of HOSO
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Javier, Carmona-García, Tarek, Trabelsi, Antonio, Francés-Monerris, Carlos A, Cuevas, Alfonso, Saiz-Lopez, Daniel, Roca-Sanjuán, and Joseph S, Francisco
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Sulfur trioxide (SO
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- 2021
23. Theoretical Study on the Photo-Oxidation and Photoreduction of an Azetidine Derivative as a Model of DNA Repair
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Antonio Francés-Monerris, Miriam Navarrete-Miguel, Miguel A. Miranda, Virginie Lhiaubet-Vallet, Daniel Roca-Sanjuán, and Ministerio de Ciencia e Innovación (España)
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Anions ,Acetonitriles ,Pyrimidine ,Light ,Photochemistry ,Azetidine ,Pharmaceutical Science ,Organic chemistry ,DNA repair ,010402 general chemistry ,Ring (chemistry) ,Oxetane ,01 natural sciences ,Article ,Analytical Chemistry ,Nucleobase ,Electron transfer ,chemistry.chemical_compound ,QUIMICA ORGANICA ,QD241-441 ,Cations ,redox properties ,Drug Discovery ,Photosensitizer ,Physical and Theoretical Chemistry ,Photolyase ,ring opening ,density functional theory ,photochemistry ,010405 organic chemistry ,Ring opening ,Models, Theoretical ,electron transfer ,0104 chemical sciences ,chemistry ,Chemistry (miscellaneous) ,Density functional theory ,Molecular Medicine ,Azetidines ,Thermodynamics ,Gases ,azetidine ,Oxidation-Reduction ,Redox properties - Abstract
Photocycloreversion plays a central role in the study of the repair of DNA lesions, reverting them into the original pyrimidine nucleobases. Particularly, among the proposed mechanisms for the repair of DNA (6-4) photoproducts by photolyases, it has been suggested that it takes place through an intermediate characterized by a four-membered heterocyclic oxetane or azetidine ring, whose opening requires the reduction of the fused nucleobases. The specific role of this electron transfer step and its impact on the ring opening energetics remain to be understood. These processes are studied herein by means of quantum-chemical calculations on the two azetidine stereoisomers obtained from photocycloaddition between 6-azauracil and cyclohexene. First, we analyze the efficiency of the electron-transfer processes by computing the redox properties of the azetidine isomers as well as those of a series of aromatic photosensitizers acting as photoreductants and photo-oxidants. We find certain stereodifferentiation favoring oxidation of the cis-isomer, in agreement with previous experimental data. Second, we determine the reaction profiles of the ring-opening mechanism of the cationic, neutral, and anionic systems and assess their feasibility based on their energy barrier heights and the stability of the reactants and products. Results show that oxidation largely decreases the ring-opening energy barrier for both stereoisomers, even though the process is forecast as too slow to be competitive. Conversely, one-electron reduction dramatically facilitates the ring opening of the azetidine heterocycle. Considering the overall quantum-chemistry findings, N,N-dimethylaniline is proposed as an efficient photosensitizer to trigger the photoinduced cycloreversion of the DNA lesion model., This work has been funded by the Generalitat Valenciana and the European Social Fund through the postdoctoral contract APOSTD/2019/149 and the project GV/2020/226. It also was funded by the Spanish Ministerio de Ciencia e Innovación (MICINN), projects CTQ2017-87054-C2-2-P and PGC2018-096684-B-I00, and a 2019 Leonardo Grant for Researchers and Cultural Creators, BBVA Foundation. The Foundation takes no responsibility for the opinions, statements, and contents of this project, which are entirely the responsibility of its authors. D.R.-S. is grateful to the Spanish MICINN for the “Ramón y Cajal” grant (Ref. RYC-2015-19234). M.N.-M. acknowledges the Generalitat Valenciana for the predoctoral grant (Ref. ACIF/2020/075).
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- 2021
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24. Hypoxia-Selective Dissociation Mechanism of a Nitroimidazole Nucleoside in a DNA Environment
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Antonio Francés-Monerris, Iñaki Tuñón, Antonio Monari, Laboratoire de Physique et Chimie Théoriques (LPCT), Institut de Chimie du CNRS (INC)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Departament de QuÍmica Física, and Universitat de València (UV)
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Substituent ,Molecular Dynamics Simulation ,010402 general chemistry ,01 natural sciences ,chemistry.chemical_compound ,Molecular dynamics ,[CHIM]Chemical Sciences ,General Materials Science ,Photosensitizer ,A-DNA ,Physical and Theoretical Chemistry ,ComputingMilieux_MISCELLANEOUS ,Photosensitizing Agents ,Nitroimidazole ,010405 organic chemistry ,Hydrogen bond ,Hydrogen Bonding ,DNA ,0104 chemical sciences ,Thymine ,chemistry ,Nitroimidazoles ,Biophysics ,Nucleic Acid Conformation ,Quantum Theory - Abstract
Photodynamic therapy is a promising approach to treat a variety of superficial tumors and other diseases. One of its major limitations arises from its dependence on molecular oxygen, which decreases the efficiency of the therapy in hypoxia conditions commonly developed by solid tumors. The present contribution reveals the molecular mechanism of a modified thymine bearing a nitroimidazole substituent, a photosensitizer able to produce highly harmful interstrand cross-links in the DNA double strand after irradiation selectively in absence of oxygen. The mechanism is resolved at a fully atomistic and electronic level relying on quantum mechanics (CASPT2, coupled-cluster, DFT, and TD-DFT methods), classical molecular dynamics, and advanced biased QM/MM simulations, revealing an energy penalty of ∼8 kcal/mol for the anionic nitromidazole release. Our findings indicate that the global interstrand cross-link production is driven by a combination of multiple factors, namely, the reverse energy penalty, the diffusion of the nitroimidazole anion, and the further reactivity of the formed thymine radical. On the basis of these results, we also suggest some possible strategies to improve the efficiency of interstrand cross-link production.
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- 2019
25. Effect of Iodination on the Photophysics of the Laser Borane anti-B18H22: Generation of Efficient Photosensitizers of Oxygen
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Lenka Slusna, Daniel Roca-Sanjuán, Jiří Dolanský, Antonio Francés-Monerris, Jonathan Bould, Kaplan Kirakci, Pavel Kubát, Dusan Lorenc, Ivana Císařová, Eva Noskovicova, Kamil Lang, Michael G. S. Londesborough, and Jakub Braborec
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010405 organic chemistry ,Singlet oxygen ,Nuclear magnetic resonance spectroscopy ,Borane ,010402 general chemistry ,Photochemistry ,01 natural sciences ,0104 chemical sciences ,Inorganic Chemistry ,chemistry.chemical_compound ,chemistry ,Yield (chemistry) ,Physical and Theoretical Chemistry ,Spectroscopy ,Phosphorescence ,Derivative (chemistry) ,Dichloromethane - Abstract
Treatment of the laser borane anti-B18H22 (compound 1) with iodine in ethanol gives the monoiodinated derivative 7-I-anti-B18H21 (compound 2) in 67% yield, or, by reaction with iodine or ICl in the presence of AlCl3 in dichloromethane, the diiodinated derivative 4,4'-I2-anti-B18H20 (compound 3) in 85% yield. On excitation with 360 nm light, both compounds 2 and 3 give strong green phosphorescent emissions (λmax = 525 nm, ΦL = 0.41 and λmax = 545 nm, ΦL = 0.71 respectively) that are quenched by dioxygen to produce O2(1Δg) singlet oxygen with quantum yields of ΦΔ = 0.52 and 0.36 respectively. Similarly strong emissions can be stimulated via the nonlinear process of two-photon absorption when exciting with 720 or 800 nm light. The high quantum yields of singlet-oxygen production, coupled with the option of two-photon excitation, make compounds 2 and 3 promising O2(1Δg) photosensitizers. The molecular structures of compounds 2 and 3 were determined by single-crystal X-ray crystallographic studies as well as multinuclear NMR spectroscopy and mass spectrometry. Time-resolved UV-vis spectroscopy was used to delineate their photophysical properties, and the electronic-structure properties of the emitting species were determined by means of multiconfigurational quantum-chemistry computations.
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- 2019
26. Hydroxyl Radical Addition to Thymine and Cytosine and Photochemistry of the Adducts at the C6 Position
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Daniel Roca-Sanjuán, Antonio Francés-Monerris, and Vicent J. Borràs
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chemistry.chemical_compound ,chemistry ,Radical ,Organic Chemistry ,Hydroxyl radical ,Physical and Theoretical Chemistry ,Photochemistry ,Cytosine ,Analytical Chemistry ,Adduct ,Thymine - Published
- 2019
27. Toward Luminescent Iron Complexes: Unravelling the Photophysics by Computing Potential Energy Surfaces
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Antonio Monari, Mariachiara Pastore, Philippe C. Gros, Antonio Francés-Monerris, Xavier Assfeld, Laboratoire de Physique et Chimie Théoriques (LPCT), Institut de Chimie du CNRS (INC)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Lorrain de Chimie Moléculaire (L2CM), Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-Université de Lorraine (UL)
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Materials science ,010304 chemical physics ,Organic Chemistry ,010402 general chemistry ,Photochemistry ,01 natural sciences ,Potential energy ,0104 chemical sciences ,Analytical Chemistry ,[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry ,Excited state ,0103 physical sciences ,Physical and Theoretical Chemistry ,Luminescence ,ComputingMilieux_MISCELLANEOUS - Abstract
International audience
- Published
- 2019
28. A theoretical analysis of the structure and properties of B26H30 isomers. Consequences to the laser and semiconductor doping capabilities of large borane clusters
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Antonio Francés-Monerris, Drahommír Hnyk, Jan Macháček, Michael G. S. Londesborough, Eluvathingal D. Jemmis, Jindřich Fanfrlík, Daniel Roca-Sanjuán, and Naiwrit Karmodak
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Materials science ,business.industry ,Doping ,Cluster chemistry ,General Physics and Astronomy ,02 engineering and technology ,Borane ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,chemistry.chemical_compound ,Semiconductor ,chemistry ,Chemical physics ,Decaborane ,Structural isomer ,Molecule ,Density functional theory ,Physical and Theoretical Chemistry ,0210 nano-technology ,business - Abstract
Decaborane(14), nido-B10H14, is the major commercially available molecular building block in boron cluster chemistry. The condensation of two such {nido-B10} blocks gives the known isomers of B18H22 – a molecule used in the fabrication of p-type semiconductors and capable of blue laser emission. Here, we computationally determine the structures and thermodynamic stabilities of 20 possible B26H30 regioisomers constructed from the fusion of three {nido-B10} blocks with the three subclusters conjoined by two-boron atom shared edges. In addition, density functional theory, time-dependent (TD)-DFT and multiconfigurational CASPT2 methods have been used to model and investigate the physical and photophysical properties of the three most stable of these isomers. Our findings predict these isomers to be potentially useful materials for the semiconductor industry, as high boron-content doping agents, and in the fabrication of new optical materials.
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- 2019
29. Towards Iron(II) Complexes with Octahedral Geometry: Synthesis, Structure and Photophysical Properties
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Emmanuel Wenger, Philippe C. Gros, Stefan Haacke, Antonio Francés-Monerris, Antonio Monari, Bogdan A. Marekha, A. Doudouh, Mohamed Darari, Laboratoire Lorrain de Chimie Moléculaire (L2CM), Institut de Chimie du CNRS (INC)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique et Chimie Théoriques (LPCT), Universitat de València (UV), Max Planck Institute for Medical Research [Heidelberg], Max-Planck-Gesellschaft, Cristallographie, Résonance Magnétique et Modélisations (CRM2), Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), Université de Strasbourg (UNISTRA)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et Nanosciences Grand-Est (MNGE), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), and GROS, PHILIPPE C.
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[CHIM.INOR] Chemical Sciences/Inorganic chemistry ,Ligand field theory ,Coordination sphere ,Materials science ,Iron ,Pharmaceutical Science ,excited states dynamics ,[CHIM.INOR]Chemical Sciences/Inorganic chemistry ,Crystallography, X-Ray ,Ligands ,010402 general chemistry ,01 natural sciences ,Article ,time-resolved spectroscopy ,Analytical Chemistry ,lcsh:QD241-441 ,Metal ,X-Ray Diffraction ,lcsh:Organic chemistry ,Drug Discovery ,Octahedral molecular geometry ,[CHIM.CRIS]Chemical Sciences/Cristallography ,iron (II) complexes ,[CHIM.COOR]Chemical Sciences/Coordination chemistry ,Ferrous Compounds ,[CHIM.CRIS] Chemical Sciences/Cristallography ,Physical and Theoretical Chemistry ,octahedral geometry ,density functional theory ,ComputingMilieux_MISCELLANEOUS ,Molecular Structure ,010405 organic chemistry ,Ligand ,Organic Chemistry ,[CHIM.COOR] Chemical Sciences/Coordination chemistry ,0104 chemical sciences ,3. Good health ,Crystallography ,Octahedron ,[CHIM.OTHE] Chemical Sciences/Other ,Chemistry (miscellaneous) ,Excited state ,visual_art ,visual_art.visual_art_medium ,Thermodynamics ,Molecular Medicine ,Density functional theory ,[CHIM.OTHE]Chemical Sciences/Other - Abstract
The control of ligand-field splitting in iron (II) complexes is critical to slow down the metal-to-ligand charge transfer (MLCT)-excited states deactivation pathways. The gap between the metal-centered states is maximal when the coordination sphere of the complex approaches an ideal octahedral geometry. Two new iron(II) complexes (C1 and C2), prepared from pyridylNHC and pyridylquinoline type ligands, respectively, have a near-perfect octahedral coordination of the metal. The photophysics of the complexes have been further investigated by means of ultrafast spectroscopy and TD-DFT modeling. For C1, it is shown that&mdash, despite the geometrical improvement&mdash, the excited state deactivation is faster than for the parent pseudo-octahedral C0 complex. This unexpected result is due to the increased ligand flexibility in C1 that lowers the energetic barrier for the relaxation of 3MLCT into the 3MC state. For C2, the effect of the increased ligand field is not strong enough to close the prominent deactivation channel into the metal-centered quintet state, as for other Fe-polypyridine complexes.
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- 2020
30. Photochemistry of oxidized Hg(I) and Hg(II) species suggests missing mercury oxidation in the troposphere
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Alfonso Saiz-Lopez, Martin Jiskra, Joseph S. Francisco, Daniel Roca-Sanjuán, John M. C. Plane, Daniel J. Jacob, Jeroen E. Sonke, Johannes Bieser, Feiyue Wang, Antonio Francés-Monerris, Colin P. Thackray, Javier Carmona-García, Juan Z. Dávalos, A. Ulises Acuña, Carlos A. Cuevas, Oleg Travnikov, Instituto de Química Física Rocasolano (IQFR), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Géosciences Environnement Toulouse (GET), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD), European Commission, Ministerio de Economía y Competitividad (España), Consejo Superior de Investigaciones Científicas (España), Generalitat Valenciana, Universidad de Valencia, Swiss National Science Foundation, Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), and Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)
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atmospheric chemistry ,Atmospheric chemistry ,010504 meteorology & atmospheric sciences ,Tropospheric chemistry ,Mercury photoreduction ,chemistry.chemical_element ,atmospheric modeling ,Atmospheric model ,010501 environmental sciences ,Photochemistry ,01 natural sciences ,Troposphere ,Mercury oxidation ,Computer Simulation ,Gas-phase mercury reactivity ,gas-phase mercury reactivity ,0105 earth and related environmental sciences ,mercury photoreduction ,Thermal oxidation ,Multidisciplinary ,Atmosphere ,Photodissociation ,Correction ,Mercury ,Models, Theoretical ,Photochemical Processes ,tropospheric chemistry ,Mercury (element) ,Atmospheric modeling ,Deposition (aerosol physics) ,chemistry ,13. Climate action ,[CHIM.OTHE]Chemical Sciences/Other ,Oxidation-Reduction - Abstract
8 pags., 5 figs., 2 tabs., Mercury (Hg), a global contaminant, is emitted mainly in its elemental form Hgto the atmosphere where it is oxidized to reactive Hgcompounds, which efficiently deposit to surface ecosystems. Therefore, the chemical cycling between the elemental and oxidized Hg forms in the atmosphere determines the scale and geographical pattern of global Hg deposition. Recent advances in the photochemistry of gas-phase oxidized Hgand Hgspecies postulate their photodissociation back to Hgas a crucial step in the atmospheric Hg redox cycle. However, the significance of these photodissociation mechanisms on atmospheric Hg chemistry, lifetime, and surface deposition remains uncertain. Here we implement a comprehensive and quantitative mechanism of the photochemical and thermal atmospheric reactions between Hg, Hg, and Hgspecies in a global model and evaluate the results against atmospheric Hg observations. We find that the photochemistry of Hgand Hgleads to insufficient Hg oxidation globally. The combined efficient photoreduction of Hgand Hgto Hgcompetes with thermal oxidation of Hg, resulting in a large model overestimation of 99% of measured Hgand underestimation of 51% of oxidized Hg and ∼66% of Hgwet deposition. This in turn leads to a significant increase in the calculated global atmospheric Hg lifetime of 20 mo, which is unrealistically longer than the 3-6-mo range based on observed atmospheric Hg variability. These results show that the Hgand Hgphotoreduction processes largely offset the efficiency of bromine-initiated Hgoxidation and reveal missing Hg oxidation processes in the troposphere., This study has received funding from the European Research Council Executive Agency under the European Union’s Horizon 2020 Research and Innovation programme (Project ERC-2016- COG 726349 CLIMAHAL) and the Spanish Ministerio de Economía y Competitividad (MINECO) /Fondo Europeo de Desarrollo Regional (FEDER) (Projects CTQ2017-87054-C2-2-P, RYC-2015-19234, and CEX2019-000919-M). This work was supported by the Consejo Superior de Investigaciones Científicas (CSIC) Spain. A.F.-M. acknowledges the Generalitat Valenciana and the European Social Fund (Contract APOSTD/2019/149 and Project GV/2020/ 226) for the financial support. J.C.-G. acknowledges the Universitat de València for his Masters Scholarship. M.J. acknowledges funding by the Swiss National Science Foundation (Grant PZ00P2_174101). The ETMEP measurements as well as ground-based measurements of the GMOS network were funded by the EU FP7-ENV-2010 project (GMOS, Grant Agreement 265113). J.S.F. acknowledges the H2020 ERA-PLANET (689443) Integrated Global Observing Systems for Persistent Pollutants (iGOSP) and Integrative and Comprehensive Understanding on Polar Environments (iCUPE) programs
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- 2020
31. Experimental and theoretical studies on thymine photodimerization mediated by oxidatively generated DNA lesions and epigenetic intermediates
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Antonio Monari, Miguel A. Miranda, Virginie Lhiaubet-Vallet, Mauricio Lineros-Rosa, Antonio Francés-Monerris, Ministerio de Economía y Competitividad (España), and Ministerio de Ciencia, Innovación y Universidades (España)
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DNA damage ,Photochemistry ,Ultraviolet Rays ,Bases ,General Physics and Astronomy ,Pyrimidine dimer ,010402 general chemistry ,01 natural sciences ,Nucleobase ,Epigenesis, Genetic ,chemistry.chemical_compound ,Triplet energy-transfer ,Cytosine ,QUIMICA ORGANICA ,Molecule ,Epigenetics ,Physical and Theoretical Chemistry ,Uracil ,010405 organic chemistry ,Dimer formation ,0104 chemical sciences ,Thymine ,Dynamics ,Damage ,Photophysics ,chemistry ,Biophysics ,Nucleic acid ,Sunlight ,Mechanism ,Photosensitization ,Dimerization ,Oxidation-Reduction ,DNA ,DNA Damage - Abstract
[EN] Interaction of nucleic acids with light is a scientific question of paramount relevance not only in the understanding of life functioning and evolution, but also in the insurgence of diseases such as malignant skin cancer and in the development of biomarkers and novel light-assisted therapeutic tools. This work shows that the UVA portion of sunlight, not absorbed by canonical DNA nucleobases, can be absorbed by 5-formyluracil (ForU) and 5-formylcytosine (ForC), two ubiquitous oxidatively generated lesions and epigenetic intermediates present in living beings in natural conditions. We measure the strong propensity of these molecules to populate triplet excited states able to transfer the excitation energy to thymine-thymine dyads, inducing the formation of cyclobutane pyrimidine dimers (CPDs). By using steady-state and transient absorption spectroscopy, NMR, HPLC, and theoretical calculations, we quantify the differences in the triplet-triplet energy transfer mediated by ForU and ForC, revealing that the former is much more efficient in delivering the excitation energy and producing the CPD photoproduct. Although significantly slower than ForU, ForC is also able to harm DNA nucleobases and therefore this process has to be taken into account as a viable photosensitization mechanism. The present findings evidence a rich photochemistry crucial to understand DNA damage photobehavior., Support from the Universite de Lorraine, CNRS, regional (Prometeo/2017/075) and Spanish Government (PGC2018-096684-B-I00, CTQ2017-87054-C2-2-P) is kindly acknowledged. A. F.-M. is grateful to Generalitat Valenciana and the European Social Fund (postdoctoral contract APOSTD/2019/149 and project GV/2020/226) for financial support. M. L.-R. acknowledges the Universitat Politecnica de Valencia for the FPI grant. All calculations have been performed on the local LPCT computer center and on the Explor regional center in the framework of the project "Dancing under the light".
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- 2020
32. Molecular basis of SARS-CoV-2 infection and rational design of potential antiviral agents: Modeling and simulation approaches
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Cristina García-Iriepa, Tom Miclot, Giampaolo Barone, Antonio Francés-Monerris, Cécilia Hognon, Antonio Monari, Isabel Iriepa, Marco Marazzi, Stéphanie Grandemange, Alessio Terenzi, Laboratoire de Physico-Chimie Théorique (LPCT), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Universitat de València (UV), Universidad de Alcalá - University of Alcalá (UAH), Università degli studi di Palermo - University of Palermo, Centre de Recherche en Automatique de Nancy (CRAN), Centre National de la Recherche Scientifique (CNRS)-Université de Lorraine (UL), Frances-Monerris A., Hognon C., Miclot T., Garcia-Iriepa C., Iriepa I., Terenzi A., Grandemange S., Barone G., Marazzi M., and Monari A.
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0301 basic medicine ,Computer science ,drug design ,In silico ,Pneumonia, Viral ,membrane fusion ,coronavirus ,Reviews ,Drug design ,Computational biology ,Molecular Dynamics Simulation ,Viral Nonstructural Proteins ,medicine.disease_cause ,spike protein ,Antiviral Agents ,Molecular Docking Simulation ,Biochemistry ,[SPI.AUTO]Engineering Sciences [physics]/Automatic ,Modeling and simulation ,Betacoronavirus ,03 medical and health sciences ,Pandemic ,medicine ,Humans ,structural biophysics ,Pandemics ,Coronavirus ,030102 biochemistry & molecular biology ,SARS-CoV-2 ,free-energy methods ,molecular modeling ,Rational design ,COVID-19 ,General Chemistry ,Virus Internalization ,SARS unique domain ,molecular dynamics ,3. Good health ,030104 developmental biology ,Docking (molecular) ,Settore CHIM/03 - Chimica Generale E Inorganica ,Spike Glycoprotein, Coronavirus ,docking ,proteases ,Coronavirus Infections - Abstract
International audience; The emergence in late 2019 of the coronavirus SARS-CoV-2 has resulted in the breakthrough of the COVID-19 pandemic that is presently affecting a growing number of countries. The development of the pandemic has also prompted an unprecedented effort of the scientific community to understand the molecular bases of the virus infection and to propose rational drug design strategies able to alleviate the serious COVID-19 morbidity. In this context, a strong synergy between the structural biophysics and molecular modeling and simulation communities has emerged, resolving at the atomistic level the crucial protein apparatus of the virus and revealing the dynamic aspects of key viral processes. In this Review, we focus on how in silico studies have contributed to the understanding of the SARS-CoV-2 infection mechanism and the proposal of novel and original agents to inhibit the viral key functioning. This Review deals with the SARS-CoV-2 spike protein, including the mode of action that this structural protein uses to entry human cells, as well as with nonstructural viral proteins, focusing the attention on the most studied proteases and also proposing alternative mechanisms involving some of its domains, such as the SARS unique domain. We demonstrate that molecular modeling and simulation represent an effective approach to gather information on key biological processes and thus guide rational molecular design strategies.
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- 2020
33. Photoinduced DNA Lesions in Dormant Bacteria: The Peculiar Route Leading to Spore Photoproducts Characterized by Multiscale Molecular Dynamics
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Antonio Monari, Thierry Douki, Cécilia Hognon, Antonio Francés-Monerris, Laboratoire de Physique et Chimie Théoriques (LPCT), Institut de Chimie du CNRS (INC)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Universitat de València (UV), Centre de Recherche en Automatique de Nancy (CRAN), Centre National de la Recherche Scientifique (CNRS)-Université de Lorraine (UL), Chimie Interface Biologie pour l’Environnement, la Santé et la Toxicologie (CIBEST ), SYstèmes Moléculaires et nanoMatériaux pour l’Energie et la Santé (SYMMES), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), Département Interfaces pour l'énergie, la Santé et l'Environnement (DIESE), Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)
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Molecular model ,DNA repair ,DNA damage ,Ultraviolet Rays ,Pyrimidine dimer ,Molecular Dynamics Simulation ,010402 general chemistry ,01 natural sciences ,Molecular mechanics ,Catalysis ,chemistry.chemical_compound ,[SDV.BBM.BC]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biochemistry [q-bio.BM] ,Spores, Bacterial ,010405 organic chemistry ,Chemistry ,Organic Chemistry ,fungi ,General Chemistry ,DNA ,0104 chemical sciences ,Spore ,Pyrimidine Dimers ,Biophysics ,Nucleic acid ,DNA Damage - Abstract
International audience; Some bacterial species enter a dormant state in the form of spores to resist to unfavorable external conditions. Spores are resistant to a wide series of stress agents, including UV radiation, and can last for tens to hundreds of years. Due to the suspension of biological functions, such as DNA repair, they accumulate DNA damage upon exposure to UV radiation. Differently from active organisms, the most common DNA photoproducts in spores are not cyclobutane pyrimidine dimers, but rather the so‐called spore photoproducts. This noncanonical photochemistry results from the dry state of DNA and its binding to small, acid‐soluble proteins that drastically modify the structure and photoreactivity of the nucleic acid. Herein, multiscale molecular dynamics simulations, including extended classical molecular dynamics and quantum mechanics/molecular mechanics based dynamics, are used to elucidate the coupling of electronic and structural factors that lead to this photochemical outcome. In particular, the well‐described impact of the peculiar DNA environment found in spores on the favored formation of the spore photoproduct, given the small free energy barrier found for this path, is rationalized. Meanwhile, the specific organization of spore DNA precludes the photochemical path that leads to cyclobutane pyrimidine dimer formation.
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- 2020
34. DNA Photodamage and Repair: Computational Photobiology in Action
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Antonio Monari, Antonio Francés-Monerris, Elise Dumont, Natacha Gillet, Laboratoire de Physique et Chimie Théoriques (LPCT), Institut de Chimie du CNRS (INC)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Universitat de València (UV), Laboratoire de Chimie - UMR5182 (LC), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut Universitaire de France (IUF), Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-École normale supérieure - Lyon (ENS Lyon)-Institut de Chimie du CNRS (INC)
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Genome instability ,0303 health sciences ,Computer science ,DNA repair ,food and beverages ,Computational biology ,010402 general chemistry ,medicine.disease_cause ,01 natural sciences ,Multiscale modeling ,0104 chemical sciences ,[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry ,03 medical and health sciences ,chemistry.chemical_compound ,Photobiology ,chemistry ,medicine ,Metabolic Stress ,Carcinogenesis ,ComputingMilieux_MISCELLANEOUS ,DNA ,030304 developmental biology - Abstract
DNA is constantly exposed to external and metabolic stress agents, including the solar radiation and in particular the UV portion of the electromagnetic spectrum. Such source of stress can induce photochemical modification of the structure of DNA and of its basic components, i.e. the nucleobases. DNA lesions may ultimately lead to genomic instability, mutations, and even to carcinogenesis. Hence, cells dispose of complex biochemical repair pathways in charge of remove the DNA lesions and avoid their accumulation. In this Chapter, we present the complexity of the DNA lesion chemical and structural space, also complicated by the intricate coupling with the biological relevant signaling pathways. Through some relevant examples, we will show how proper multiscale simulation protocols can provide a unified picture of the complex phenomena and hence answer biological relevant questions, paving the way to a veritable computational photobiology approach.
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- 2020
35. Thermodynamics of the interaction between the spike protein of severe acute respiratory syndrome- coronavirus-2 and the receptor of human angiotensin converting enzyme 2. Effects of possible ligands
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Giampaolo Barone, Cécilia Hognon, Marco Marazzi, Tom Miclot, Cristina García-Iriepa, Antonio Francés-Monerris, Antonio Monari, and Isabel Iriepa
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chemistry.chemical_classification ,Enzyme ,chemistry ,Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ,Angiotensin-converting enzyme 2 ,medicine ,Spike Protein ,Computational biology ,medicine.disease_cause ,Receptor ,Transmembrane protein ,Coronavirus ,Protein–protein interaction - Abstract
Since the end of 2019, the coronavirus SARS-CoV-2 has caused more than 180,000 deaths all over the world, still lacking a medical treatment despite the concerns of the whole scientific community. Human Angiotensin-Converting Enzyme 2 (ACE2) was recently recognized as the transmembrane protein serving as SARS-CoV-2 entry point into cells, thus constituting the first biomolecular event leading to COVID-19 disease. Here, by means of a state-of-the-art computational approach, we propose a rational evaluation of the molecular mechanisms behind the formation of the complex and of the effects of possible ligands. Moreover, binding free energy between ACE2 and the active Receptor Binding Domain (RBD) of the SARS-CoV-2 spike protein is evaluated quantitatively, assessing the molecular mechanisms at the basis of the recognition and the ligand-induced decreased affinity. These results boost the knowledge on the molecular grounds of the SARS-CoV-2 infection and allow to suggest rationales useful for the subsequent rational molecular design to treat severe COVID-19 cases.
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- 2020
36. Thermodynamics of the interaction between the spike protein of severe acute respiratory syndrome- coronavirus-2 and the receptor of human angiotensin converting enzyme 2. Effects of possible ligands
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Marco Marazzi, Antonio Monari, Giampaolo Barone, Tom Miclot, Isabel Iriepa, Antonio Francés-Monerris, Cecilia Hognon, and Cristina Garcia-Iriepa
- Abstract
Since the end of 2019, the coronavirus SARS-CoV-2 has caused more than 180,000 deaths all over the world, still lacking a medical treatment despite the concerns of the whole scientific community. Human Angiotensin-Converting Enzyme 2 (ACE2) was recently recognized as the transmembrane protein serving as SARS-CoV-2 entry point into cells, thus constituting the first biomolecular event leading to COVID-19 disease. Here, by means of a state-of-the-art computational approach, we propose a rational evaluation of the molecular mechanisms behind the formation of the complex and of the effects of possible ligands. Moreover, binding free energy between ACE2 and the active Receptor Binding Domain (RBD) of the SARS-CoV-2 spike protein is evaluated quantitatively, assessing the molecular mechanisms at the basis of the recognition and the ligand-induced decreased affinity. These results boost the knowledge on the molecular grounds of the SARS-CoV-2 infection and allow to suggest rationales useful for the subsequent rational molecular design to treat severe COVID-19 cases.
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- 2020
37. Photophysical Investigation of Iron(II) Complexes Bearing Bidentate Annulated Isomeric Pyridine-NHC Ligands
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Kevin Magra, Antonio Monari, Mohamed Darari, Antonio Francés-Monerris, Philippe C. Gros, Marc Beley, Cristina Cebrián, Edoardo Domenichini, Mariachiara Pastore, Xavier Assfeld, Stefan Haacke, Laboratoire de Physique et Chimie Théoriques (LPCT), Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Lorrain de Chimie Moléculaire (L2CM), Institut de Chimie du CNRS (INC)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et Nanosciences Grand-Est (MNGE), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Universitat de València (UV), GROS, PHILIPPE C., Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), Centre National de la Recherche Scientifique (CNRS)-Université de Lorraine (UL), Université de Strasbourg (UNISTRA)-Matériaux et nanosciences d'Alsace, Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, and Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Université de Strasbourg (UNISTRA)
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[CHIM.INOR] Chemical Sciences/Inorganic chemistry ,Denticity ,02 engineering and technology ,[CHIM.INOR]Chemical Sciences/Inorganic chemistry ,010402 general chemistry ,01 natural sciences ,Chemical synthesis ,chemistry.chemical_compound ,Pyridine ,Polymer chemistry ,[CHIM] Chemical Sciences ,[CHIM]Chemical Sciences ,[CHIM.COOR]Chemical Sciences/Coordination chemistry ,Physical and Theoretical Chemistry ,fused NHC ,ComputingMilieux_MISCELLANEOUS ,photophysics ,Ligand ,Minimum Energy Path ,[CHIM.COOR] Chemical Sciences/Coordination chemistry ,021001 nanoscience & nanotechnology ,3. Good health ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry ,[CHIM.THEO] Chemical Sciences/Theoretical and/or physical chemistry ,General Energy ,iron complexes ,chemistry ,decay process ,0210 nano-technology ,Luminescence ,TD-DFT - Abstract
The possibility of achieving luminescent and photophysically active metal-organic compounds relies on the stabilization of charge transfer states and kinetically and thermodynamically blocking non-...
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- 2020
38. Thymine Dimerization Induced by Oxidative DNA Lesions and Epigenetic Intermediates via Triplet-Triplet Energy Transfer
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Virginie Lhiaubet-Vallet, Mauricio Lineros-Rosa, Antonio Francés-Monerris, Antonio Monari, and Miguel A. Miranda
- Subjects
chemistry.chemical_compound ,chemistry ,DNA damage ,Nucleic acid ,Biophysics ,Pyrimidine dimer ,Epigenetics ,DNA oxidation ,DNA ,Thymine ,Nucleobase - Abstract
Interaction of nucleic acids with light is a scientific question of paramount relevance not only in the understanding of life functioning and evolution, but also in the insurgence of diseases such as malignant skin cancer and in the development of biomarkers and novel light-assisted therapeutic tools. This work shows that the UVA portion of sunlight, not absorbed by canonical DNA nucleobases, can be absorbed by 5-formyluracil (ForU) and 5-formylcytosine (ForC), two ubiquitous oxidative lesions and epigenetic intermediates present in living beings in natural conditions. We measure the strong propensity of these molecules to populate triplet excited states able to transfer the excitation energy to thymine-thymine dyads, inducing the formation of the highly toxic and mutagenic cyclobutane pyrimidine dimers (CPDs). By using steady-state and transient absorption spectroscopy, NMR, HPLC, and theoretical calculations, we quantify the differences in the triplet-triplet energy transfer mediated by ForU and ForC, revealing that the former is much more efficient in delivering the excitation energy and producing the CPD photoproduct. Although significantly slower than ForU, ForC is also able to harm DNA nucleobases and therefore this process has to be taken into account as a viable photosensitization mechanism. The present findings evidence a rich photochemistry crucial to understand DNA photodamage and of potential use in the development of biomarkers and non-conventional photodynamic therapy agents.
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- 2020
39. Has Ivermectin Virus-Directed Effects against SARS-CoV-2? Rationalizing the Action of a Potential Multitarget Antiviral Agent
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Antonio Monari, Tom Miclot, Cécilia Hognon, Cristina García-Iriepa, Antonio Francés-Monerris, Isabel Iriepa, Marco Marazzi, and Giampaolo Barone
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Proteases ,Immune system ,Ivermectin ,Viral replication ,Viral protein ,medicine ,Biology ,medicine.disease_cause ,Approved drug ,Virology ,Virus ,Coronavirus ,medicine.drug - Abstract
The novel SARS-CoV-2 coronavirus is causing a devastating pandemic in 2020, threatening public health in many countries. An unprecedented rapid and global response has been set in motion to identify efficient antiviral agents against SARS-CoV-2, mostly relying on the repurposing of drugs presenting or not previously known antiviral activity. Ivermectin is an approved drug used as antiparasitic in humans and animals with well documented broad-spectrum antiviral properties that emerge from host-directed effects. Recent results reported by Wagstaff and coworkers (Antiviral Research 2020, 178, 104787) show a potent inhibition of SARS-CoV-2 replication in vitro by ivermectin, and clinical trials with human volunteers have already started. However, the mode of action of ivermectin is still largely unknown, especially at the molecular level. Here, we employ advanced molecular dynamics simulations to assess the influence of ivermectin on several key viral protein targets, with the aim to reveal the molecular bases of antiviral mechanisms against SARS-CoV-2. Interestingly, we show that ivermectin could be regarded as a multitarget agent, inhibiting different viral functions. These include blocking the recognition by the SARS-CoV-2 Receptor Binding Domain (RBD) of the Angiotensin-Converting Enzyme 2 (ACE2), the interactions with the two viral proteases 3CLpro and PLpro, and the SARS Unique Domain (SUD) non-structural protein. Hence, the wide spectrum of actions involving i) the interference with cell infection, ii) the inhibition of viral replication, and iii) elusion of the host immune system, could point to an unprecedented synergy between host- and virus-directed effects explaining the high anti-SARS-CoV-2 activity observed for this compound.
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- 2020
40. Unveiling the role of upper excited electronic states in the photochemistry and laser performance of: anti -B18H22
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Jiří Dolanský, Michael G. S. Londesborough, Marcel Fuciman, Antonio Francés-Monerris, Daniel Roca-Sanjuán, Luis Cerdán, Jonathan Bould, Czech Science Foundation, Ministerio de Economía y Competitividad (España), Generalitat Valenciana, and Ministerio de Ciencia, Innovación y Universidades (España)
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Blue laser ,education.field_of_study ,Materials science ,Population ,General Chemistry ,Borane ,Laser ,Photochemistry ,Quantum chemistry ,law.invention ,chemistry.chemical_compound ,chemistry ,Atomic orbital ,law ,Excited state ,Materials Chemistry ,Spectroscopy ,education - Abstract
13 pags., 7 figs., -- This article is part of the themed collection: Journal of Materials Chemistry C HOT Papers, In the search for innovative new light sources, the discovery that solutions of the boron hydride anti-B18H22 generate photostable blue laser emission stands out in its significance as the first laser borane. Surprisingly, though, the laser performance of anti-B18H22 (∼10% efficiency) does not match the expectations based on its exceptional photophysical properties (Φf = 0.97 and high photostability). To understand this contradiction, we herein present an investigation into the upper excited states of the anti-B18H22 photophysical system, which we suggest to be the most relevant factor to its laser performance. The use of computational quantum chemistry, laser and UV-vis spectroscopy, NMR spectroscopy, and mass spectrometry unveil the role of the upper excited states on the laser performance of anti-B18H22, showing that efficient excited state absorption (ESA) leads to the population of these states, and results not only in the loss of laser efficiency, but also in the activation of chemically reactive relaxation pathways and the formation of photochemically produced novel molecular species. The likely composition of these photoproducts, formed upon prolonged high intensity laser irradiation, is inferred from their molecular masses, NMR properties, and calculated natural orbitals. Together, these results are of key importance to the complete understanding of the anti-B18H22 photophysical system and provide valuable information to chemists and laser physicists working to mitigate deficiencies and enhance the performance of the next generation of borane lasers and borane-based photoactive materials., This work has been supported by the Czech Science Foundation (project No. 18-20286S). L. C. acknowledges financial support from the Spanish Ministerio de Economı´a y Competitividad (MINECO) through Grant number MAT2017-83856-C3-1. A. F.-M. is grateful to Generalitat Valenciana and the European Social Fund for a postdoctoral contract (APOSTD/2019/149). D. R.-S. is thankful to the Spanish MINECO/FEDER for financial support through the Ramon y Cajal fellowship (RYC-2015-19234) and the Unit of Excellence Maria de Maeztu (MDM-2015-0538). Support from the project CTQ2017-87054-C2-2-P (Ministerio de Ciencia e Innovacion) is gratefully acknowledged.
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- 2020
41. Iron’s Wake: The Performance of Quantum Mechanical-Derived Versus General-Purpose Force Fields Tested on a Luminescent Iron Complex
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Antonio Francés-Monerris, Antonio Monari, Mariachiara Pastore, Valentin Diez-Cabanes, Giacomo Prampolini, Laboratoire de Physique et Chimie Théoriques (LPCT), Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), ICCOM-CNR UOS Pisa, and Universitat de València (UV)
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Work (thermodynamics) ,Acetonitriles ,Luminescence ,Iron ,Pharmaceutical Science ,Molecular Dynamics Simulation ,010402 general chemistry ,01 natural sciences ,Article ,Analytical Chemistry ,lcsh:QD241-441 ,Molecular dynamics ,chemical environment ,lcsh:Organic chemistry ,0103 physical sciences ,Drug Discovery ,time-dependent density functional theory ,Statistical physics ,Physical and Theoretical Chemistry ,Quantum ,ComputingMilieux_MISCELLANEOUS ,Physics ,010304 chemical physics ,Spectrum Analysis ,Scale (chemistry) ,Organic Chemistry ,Time-dependent density functional theory ,Nanosecond ,0104 chemical sciences ,[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry ,iron complex ,Chemistry (miscellaneous) ,Excited state ,Solvents ,Quantum Theory ,Molecular Medicine ,Iron Compounds ,force field molecular dynamics - Abstract
Recently synthetized iron complexes have achieved long-lived excited states and stabilities which are comparable, or even superior, to their ruthenium analogues, thus representing an eco-friendly and cheaper alternative to those materials based on rare metals. Most of computational tools which could help unravel the origin of this large efficiency rely on ab-initio methods which are not able, however, to capture the nanosecond time scale underlying these photophysical processes and the influence of their realistic environment. Therefore, it exists an urgent need of developing new low-cost, but still accurate enough, computational methodologies capable to deal with the steady-state and transient spectroscopy of transition metal complexes in solution. Following this idea, here we focus on the comparison between general-purpose transferable force-fields (FFs), directly available from existing databases, and specific quantum mechanical derived FFs (QMD-FFs), obtained in this work through the Joyce procedure. We have chosen a recently reported FeIII complex with nanosecond excited-state lifetime as a representative case. Our molecular dynamics (MD) simulations demonstrated that the QMD-FF nicely reproduces the structure and the dynamics of the complex and its chemical environment within the same precision as higher cost QM methods, whereas general-purpose FFs failed in this purpose. Although in this particular case the chemical environment plays a minor role on the photo physics of this system, these results highlight the potential of QMD-FFs to rationalize photophysical phenomena provided an accurate QM method to derive its parameters is chosen.
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- 2020
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42. Photoinduced DNA Lesions in Dormant Bacteria. The Peculiar Route Leading to Spore Photoproduct Unraveled by Multiscale Molecular Dynamics
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Thierry Douki, Cécilia Hognon, Antonio Francés-Monerris, and Antonio Monari
- Subjects
biology ,DNA repair ,Chemistry ,DNA damage ,fungi ,Pyrimidine dimer ,biology.organism_classification ,Spore ,chemistry.chemical_compound ,Molecular dynamics ,Nucleic acid ,Biophysics ,Bacteria ,DNA - Abstract
Some bacterial species enter a dormant state in the form of spores to resist to unfavorable external conditions. Spores are resistant to a wide series of stress agents, including UV radiation, and can last for tens to hundreds of years. Due to the suspension of biological functions such as DNA repair, they accumulate DNA damage upon exposure to UV radiation. Differently from active organisms, the most common DNA photoproduct in spores are not cyclobutane pyrimidine dimers, but rather the so-called spore photoproduct. This non-canonical photochemistry results from the dry state of DNA and the binding to small acid soluble proteins that drastically modify the structure and photoreactivity of the nucleic acid. In this contribution, we use multiscale molecular dynamics simulations including extended classical molecular dynamics and QM/MM biased dynamics to elucidate the coupling of electronic and structural factors leading to this photochemical outcome. In particular, we rationalize the well-described impact of the peculiar DNA environment found in spores on the favored formation of the spore photoproduct, given the small free energy barrier found for this path. Meanwhile, the specific organization of spore DNA precludes the photochemical path leading to cyclobutane pyrimidine dimers formation.TOC GRAPHICS
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- 2020
43. Thermodynamics of the Interaction Between SARS-CoV-2 Spike Protein and Human ACE2 Receptor. Effects of Possible Ligands
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Cristina Garcia-Iriepa, Cecilia Hognon, Antonio Francés-Monerris, Isabel Iriepa, Tom Miclot, Giampaolo Barone, Antonio Monari, and Marco Marazzi
- Abstract
Since the end of 2019, the coronavirus SARS-CoV-2 has caused more than 180,000 deaths all over the world, still lacking a medical treatment despite the concerns of the whole scientific community. Human Angiotensin-Converting Enzyme 2 (ACE2) was recently recognized as the transmembrane protein serving as SARS-CoV-2 entry point into cells, thus constituting the first biomolecular event leading to COVID-19 disease. Here, by means of a state-of-the-art computational approach, we propose a rational evaluation of the molecular mechanisms behind the formation of the complex and of the effects of possible ligands. Moreover, binding free energy between ACE2 and the active Receptor Binding Domain (RBD) of the SARS-CoV-2 spike protein is evaluated quantitatively, assessing the molecular mechanisms at the basis of the recognition and the ligand-induced decreased affinity. These results boost the knowledge on the molecular grounds of the SARS-CoV-2 infection and allow to suggest rationales useful for the subsequent rational molecular design to treat severe COVID-19 cases.
- Published
- 2020
44. Photoinduced intersystem crossing in DNA oxidative lesions and epigenetic intermediates
- Author
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Miguel A. Miranda, Antonio Monari, Virginie Lhiaubet-Vallet, Mauricio Lineros-Rosa, Antonio Francés-Monerris, Ministerio de Ciencia, Innovación y Universidades (España), Generalitat Valenciana, Laboratoire de Physique et Chimie Théoriques (LPCT), Institut de Chimie du CNRS (INC)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), and Universitat Politècnica de València (UPV)
- Subjects
Models, Molecular ,Molecular model ,Light ,Oxidative phosphorylation ,010402 general chemistry ,01 natural sciences ,Catalysis ,Epigenesis, Genetic ,chemistry.chemical_compound ,Cytosine ,QUIMICA ORGANICA ,Materials Chemistry ,[CHIM]Chemical Sciences ,Humans ,Computer Simulation ,Epigenetics ,Spectroscopy ,Uracil ,ComputingMilieux_MISCELLANEOUS ,010405 organic chemistry ,Chemistry ,Metals and Alloys ,General Chemistry ,DNA ,Potential energy ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Kinetics ,Intersystem crossing ,Excited state ,Ceramics and Composites ,Biophysics ,Oxidation-Reduction ,Mutagens - Abstract
[EN] The propensity of 5-formyluracil and 5-formylcytosine, i.e. oxidative lesions and epigenetic intermediates, in acting as intrinsic DNA photosensitizers is unraveled by using a combination of molecular modeling, simulation and spectroscopy. Exploration of potential energy surfaces and non-adiabatic dynamics confirm a higher intersystem crossing rate for 5-formyluracil, whereas the kinetic models evidence different equilibria in the excited states for both compounds., Support from the Universite de Lorraine, CNRS and Spanish Government (PGC2018-096684-B-I00) is kindly acknowledged. A. F.-M. is grateful to Generalitat Valenciana (CTQ2017-87054-C2-2-P) and the European Social Fund for a postdoctoral contract (APOSTD/2019/149), M. L.-R. acknowledges the Universitat Politecnica de Valencia for the FPI grant. Calculations have been performed on the local LPCT computer center and on the Explor regional center in the framework of the project "Dancing under the light''.
- Published
- 2020
45. Role of RNA Guanine Quadruplexes in Favoring the Dimerization of SARS Unique Domain in Coronaviruses
- Author
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Cécilia Hognon, Antonio Monari, Antonio Francés-Monerris, Giampaolo Barone, Tom Miclot, Alessio Terenzi, Stéphanie Grandemange, Marco Marazzi, Cristina Garcia Iriepa, Hognon C., Miclot T., Garcla-Iriepa C., Frances-Monerris A., Grandemange S., Terenzi A., Marazzi M., Barone G., Monari A., Laboratoire de Physique et Chimie Théoriques (LPCT), Institut de Chimie du CNRS (INC)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Università degli studi di Palermo - University of Palermo, Universidad de Alcalá - University of Alcalá (UAH), Chemical Research Institute 'Andrés M. del Río' (IQAR),Universidad de Alcalá, Instituto de Ciencia Molecular (ICMol), Universitat de València (UV), Centre de Recherche en Automatique de Nancy (CRAN), and Centre National de la Recherche Scientifique (CNRS)-Université de Lorraine (UL)
- Subjects
Models, Molecular ,0301 basic medicine ,Letter ,Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ,Dimer ,Pneumonia, Viral ,Coronaviru ,Protein dimer ,Molecular Dynamics Simulation ,Viral infection ,01 natural sciences ,Virus ,Betacoronavirus ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,0103 physical sciences ,G-Quadruplexe ,Humans ,[CHIM]Chemical Sciences ,General Materials Science ,030212 general & internal medicine ,Physical and Theoretical Chemistry ,Pandemics ,Economic consequences ,030304 developmental biology ,0303 health sciences ,010304 chemical physics ,Betacoronaviru ,SARS-CoV-2 ,Chemistry ,Coronavirus Infection ,Rational design ,COVID-19 ,RNA ,Spike Glycoprotein ,3. Good health ,G-Quadruplexes ,030104 developmental biology ,Settore CHIM/03 - Chimica Generale E Inorganica ,Spike Glycoprotein, Coronavirus ,Biophysics ,RNA, Viral ,Coronavirus Infections ,Guanine-Quadruplexes ,Dimerization ,Protein Binding - Abstract
Coronaviruses may produce severe acute respiratory syndrome (SARS). As a matter of fact, a new SARS-type virus, SARS-CoV-2, is responsible of a global pandemic in 2020 with unprecedented sanitary and economic consequences for most countries. In the present contribution we study, by all-atom equilibrium and enhanced sampling molecular dynamics simulations, the interaction between the SARS Unique Domain and RNA guanine quadruplexes, a process involved in eluding the defensive response of the host thus favoring viral infection of human cells. Our results evidence two stable binding modes involving an interaction site spanning either the protein dimer interface or only one monomer. The free energy profile unequivocally points to the dimer mode as the thermodynamically favored one. The effect of these binding modes in stabilizing the protein dimer was also assessed, being related to its biological role in assisting SARS viruses to bypass the host protective response. This work also constitutes a first step of the possible rational design of efficient therapeutic agents aiming at perturbing the interaction between SARS Unique Domain and guanine quadruplexes, hence enhancing the host defenses against the virus.TOC GRAPHICS
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- 2020
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46. Photochemistry, chemiluminescence and dark photochemistry: computational advances (2018–2019)
- Author
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Antonio Francés-Monerris, Javier Segarra-Martí, Antonio Monari, B.-W. Ding, Angelo Giussani, Javier Carmona-García, Daniel Roca-Sanjuán, Y.-J. Liu, and Miriam Navarrete-Miguel
- Subjects
chemistry.chemical_compound ,law ,Chemistry ,Excited state ,Light emission ,Boranes ,Spectroscopy ,Photochemistry ,Quantum chemistry ,Quantum computer ,Chemiluminescence ,law.invention ,Luminol - Abstract
Recent progress (2018–2019) in the field of quantum chemistry applied to the excited electronic state are presented in this book chapter. General developments of methods and theory are described first, followed by applications organised in three main topics, (i) photo-induced chemistry (photochemistry), (ii) chemically induced light emission (chemiluminescence) and (iii) chemically induced excited-state chemistry (dark photochemistry). We shall highlight in this occasion developments of machine learning, GPU and quantum computing algorithms for excited states, non-adiabatic new methodological approaches, sunlight chemistry of atmospheric mercury compounds, boranes and stilbenoids photochemistry, DNA spectroscopy and excited-state chemistry, the bio/chemiluminescence mechanism of luminol and distinct luciferin-luciferase complexes and retinal activation in the dark.
- Published
- 2020
47. A Series of Ultra-Efficient Blue Borane Fluorophores
- Author
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Michael G. S. Londesborough, Tomáš Polívka, Antonio Francés-Monerris, Paul G. Waddell, Marcel Fuciman, Kamil Lang, Luis Cerdán, Kaplan Kirakci, Jonathan Bould, Daniel Roca-Sanjuán, William Clegg, Czech Science Foundation, Academy of Sciences of the Czech Republic, Generalitat Valenciana, and Ministerio de Ciencia, Innovación y Universidades (España)
- Subjects
Active laser medium ,Series (mathematics) ,010405 organic chemistry ,Hydride ,chemistry.chemical_element ,Borane ,Alkylation ,010402 general chemistry ,Laser ,01 natural sciences ,Combinatorial chemistry ,0104 chemical sciences ,law.invention ,Inorganic Chemistry ,chemistry.chemical_compound ,chemistry ,law ,Physical and Theoretical Chemistry ,Boron - Abstract
13 pags., 14 figs., 5 tabs., We present the first examples of alkylated derivatives of the macropolyhedral boron hydride, anti-B18H22, which is the gain medium in the first borane laser. This new series of ten highly stable and colorless organic-inorganic hybrid clusters are capable of the conversion of UVA irradiation to blue light with fluorescence quantum yields of unity. This study gives a comprehensive description of their synthesis, isolation, and structural characterization together with a delineation of their photophysical properties using a combined theoretical and experimental approach. Treatment of anti-B18H22 1 with RI (where R = Me or Et) in the presence of AlCl3 gives a series of alkylated derivatives, Rx-anti-B18H22-x (where x = 2 to 6), compounds 2-6, in which the 18-vertex octadecaborane cluster architectures are preserved and yet undergo a linear "polyhedral swelling", depending on the number of cluster alkyl substituents. The use of dichloromethane solvent in the synthetic procedure leads to dichlorination of the borane cluster and increased alkylation to give Me11-anti-B18H9Cl2 11, Me12-anti-B18H8Cl2 12, and Me13-anti-B18H7Cl2 13. All new alkyl derivatives are highly stable, extremely efficient (φF = 0.76-1.0) blue fluorophores (λems = 423-427 nm) and are soluble in a wide range of organic solvents and also a polystyrene matrix. The Et4-anti-B18H18 derivative 4b crystallizes from pentane solution in two phases with consequent multiabsorption and multiemission photophysical properties. An ultrafast transient UV-vis absorption spectroscopic study of compounds 4a and 4b reveals that an efficient excited-state absorption at the emission wavelength inhibits the laser performance of these otherwise remarkable luminescent molecules. All these new compounds add to the growing portfolio of octadecaborane-based luminescent species, and in an effort to broaden the perspective on their highly emissive photophysical properties, we highlight emerging patterns that successive substitutions have on the molecular size of the 18-vertex borane cluster structure and the distribution of the electron density within., This work was supported by the Czech Science Foundation (Project No. 18-20286S). We also acknowledge the working group Interactions of Inorganic Clusters, Cages, and Containers with Light within the AV21 Strategy, Czech Academy of Sciences. W.C. and P.G.W. thank Diamond Light Source for access to beamline I19 in remote-access mode (beam-time award CY22240). A.F.-M. is grateful to Generalitat Valenciana and the European Social Fund (postdoctoral contract APOSTD/2019/149 and project GV/2020/226) for financial support. A.F.-M. and D.R.-S. also acknowledge support from the Ministerio de Ciencia e Innovacioń (project CTQ2017- 87054-C2-2-P).
- Published
- 2020
48. Photodissociation Mechanisms of Major Mercury(II) Species in the Atmospheric Chemical Cycle of Mercury
- Author
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Javier Carmona-García, Juan Z. Dávalos, Joseph S. Francisco, Alfonso Saiz-Lopez, A. Ulises Acuña, Carlos A. Cuevas, Daniel Roca-Sanjuán, Antonio Francés-Monerris, Douglas E. Kinnison, Ministerio de Economía y Competitividad (España), Ministerio de Ciencia, Innovación y Universidades (España), Generalitat Valenciana, and European Commission
- Subjects
Thermal oxidation ,Chemical substance ,010405 organic chemistry ,Photodissociation ,chemistry.chemical_element ,Elemental mercury ,General Medicine ,General Chemistry ,010402 general chemistry ,Photochemistry ,7. Clean energy ,01 natural sciences ,Catalysis ,0104 chemical sciences ,Mercury (element) ,Metal ,chemistry ,13. Climate action ,visual_art ,Atmospheric chemistry ,Thermal ,visual_art.visual_art_medium - Abstract
7 pags., 4 figs., Mercury is a contaminant of global concern that is transported throughout the atmosphere as elemental mercury Hg and its oxidized forms Hg and Hg. The efficient gas-phase photolysis of Hg and Hg has recently been reported. However, whether the photolysis of Hg leads to other stable Hg species, to Hg, or to Hg and its competition with thermal reactivity remain unknown. Herein, we show that all oxidized forms of mercury rapidly revert directly and indirectly to Hg by photolysis. Results are based on non-adiabatic dynamics simulations, in which the photoproduct ratios were determined with maximum errors of 3%. We construct for the first time a complete quantitative mechanism of the photochemical and thermal conversion between atmospheric Hg, Hg, and Hg compounds. These results reveal new fundamental chemistry that has broad implications for the global atmospheric Hg cycle. Thus, photoreduction clearly competes with thermal oxidation, with Hg being the main photoproduct of Hg photolysis in the atmosphere, which significantly increases the lifetime of this metal in the environment., Ministerio de Economía y Competitividad. Grant Numbers: CTQ2017-87054-C2-2-P, RYC- 2015-19234, MDM-2015-0538 Generalitat Valenciana. Grant Number: APOSTD/2019/149 European Research Council. Grant Number: ERC-2016-COG 726349 CLIMAHAL
- Published
- 2019
49. Triplet photosensitization mechanism of thymine by an oxidized nucleobase: from a dimeric model to DNA environment
- Author
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Antonio Monari, Miguel A. Miranda, Antonio Francés-Monerris, Virginie Lhiaubet-Vallet, Cécilia Hognon, Laboratoire de Physique et Chimie Théoriques (LPCT), Institut de Chimie du CNRS (INC)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), and Universitat Politècnica de València (UPV)
- Subjects
DNA damage ,5-Methyl-2-Pyrimidone Deoxyribonucleoside ,Dimer ,Population ,General Physics and Astronomy ,Pyrimidine dimer ,Charge-Transfer ,010402 general chemistry ,Photochemistry ,01 natural sciences ,Photodynamic therapy ,Nucleobase ,chemistry.chemical_compound ,QUIMICA ORGANICA ,Nucleic-Acids ,[CHIM]Chemical Sciences ,Photosensitivity Disorders ,Physical and Theoretical Chemistry ,Cyclobutane Pyrimidine dimers ,education ,ComputingMilieux_MISCELLANEOUS ,Molecular-Dynamics ,Biological consequences ,education.field_of_study ,Singlet oxygen ,010405 organic chemistry ,DNA ,Cellular-DNA ,0104 chemical sciences ,Thymine ,chemistry ,Pyrimidine Dimers ,Nucleic acid ,UV-Irradiated DNA ,Oxidation-Reduction ,DNA Damage - Abstract
[EN] Nucleic acids are constantly exposed to external agents that can induce chemical and photochemical damage. In spite of the great advances achieved in the last years, some molecular mechanisms of DNA damage are not completely understood yet. A recent experimental report (I. Aparici-Espert et al., ACS Chem. Biol. 2018, 13, 542) proved the ability of 5-formyluracil (ForU), a common oxidatively generated product of thymine, to act as an intrinsic sensitizer of nucleic acids, causing single strand breaks and cyclobutane pyrimidine dimers in plasmid DNA. In the present contribution, we use theoretical methodologies to study the triplet photosensitization mechanism of thymine exerted by ForU in a model dimer and in DNA environment. The photochemical pathways in the former system are described combining the CASPT2 and TD-DFT methods, whereas molecular dynamics simulations and QM/MM calculations are employed for the DNA duplex. It is unambiguously shown that the (1)n,* state localised in ForU mediates the population of the triplet manifold, most likely the (3),* state centred in ForU, whereas the (3),* state localized in thymine can be populated via triplet-triplet energy transfer given the small energy barrier of, A. F. M. is grateful to Région Grand Est government (France) for the financial support. Spanish government (CTQ2015-70164P and CTQ2017-87054-C2-2-P projects) and Regional government (Prometeo/2017/075) are also acknowledged.
- Published
- 2018
50. Substitution of the laser borane anti-B18H22 with pyridine: a structural and photophysical study of some unusually structured macropolyhedral boron hydrides
- Author
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Kamil Lang, Antonio Francés-Monerris, John D. Kennedy, William Clegg, Robert D. Kennedy, Jiří Dolanský, Tomáš Jelínek, Michael G. S. Londesborough, Ivana Císařová, and Daniel Roca-Sanjuán
- Subjects
010405 organic chemistry ,Quantum yield ,Nuclear magnetic resonance spectroscopy ,Borane ,010402 general chemistry ,01 natural sciences ,0104 chemical sciences ,Inorganic Chemistry ,chemistry.chemical_compound ,Crystallography ,symbols.namesake ,chemistry ,Pyridine ,symbols ,Picoline ,van der Waals force ,Phosphorescence ,Derivative (chemistry) - Abstract
Reaction of anti-B18H221 with pyridine in neutral solvents gives sparingly soluble B16H18-3',8'-Py23a as the major product (ca. 53%) and B18H20-6',9'-Py22 (ca. 15%) as the minor product, with small quantities of B18H20-8'-Py 4 (ca. 1%) also being formed. The three new compounds 2, 3a and 4 are characterized by single-crystal X-ray diffraction analyses and by multinuclear multiple-resonance NMR spectroscopy. Compound 2 is of ten-vertex nido:ten-vertex arachno two-atoms-in-common architecture, long postulated for a species with borons-only cluster constitution, but previously elusive. Compound 3a is of unprecedented ten-vertex nido:eight-vertex arachno two-atoms-in-common architecture. The single-crystal X-ray diffraction analysis for the picoline derivative B16H18(NC5H4Me)23b, similarly obtained, is also presented. B18H20Py 4 is also previously unreported but is of known ten-vertex nido:ten-vertex nido two-atoms-in-common architecture of anti configuration, but now with the pyridine ligand positioned differently to other reported examples of B18H20L compounds. Factors behind the remarkably low solubility of 3a and 3b are elucidated in terms of electrostatic potential (ESP) calculations, polarity, and van der Waals complementarities. In view of contemporary developing high interest in the fluorescent properties of macropolyhedral boron-containing species, a detailed assessment of the photophysical characteristics of 3a and 4 is also presented. In contrast to the thermochromic fluorescence of 2 (from 620 nm brick-red at room temperature to 585 nm yellow at 8 K, quantum yield 0.15), compound 3a is only weakly phosphorescent in the yellow region (590 nm, quantum yield 0.01), whereas compound 4 exhibits no luminescence. The far more photoactive nature of compound 2 is associated with S1 excited-state minima structures that differ from each other only by the relative rotational positions of the pyridine substituents on its disubstituted ten-vertex {arachno-B10Py2}-subcluster. The wavelength and relative intensity of fluorescence from these structures depends on the rotational positions of the pyridine ligands, which in turn are influenced by temperature and/or rotational inhibition in the solid-state.
- Published
- 2018
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