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Lessa TLADS, Correia TML, Santos TCD, da Silva RP, Silva BPD, Cavallini MCM, Rocha LS, Souza Peixoto A, Cugnasca BS, Cervi G, Correra TC, Gonçalves AC, Festuccia WTL, Cunha TM, Yatsuda R, de Magalhães ACM, Dos Santos AA, Meotti FC, Queiroz RF. A novel diselenide attenuates the carrageenan-induced inflammation by reducing neutrophil infiltration and the resulting tissue damage in mice. Free Radic Res 2024:1-20. [PMID: 38588405 DOI: 10.1080/10715762.2024.2336566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Accepted: 02/06/2024] [Indexed: 04/10/2024]
Abstract
Selenium-containing compounds have emerged as promising treatment for redox-based and inflammatory diseases. This study aimed to investigate the in vitro and in vivo anti-inflammatory activity of a novel diselenide named as dibenzyl[diselanediyIbis(propane-3-1diyl)] dicarbamate (DD). DD reacted with HOCl (k = 9.2 x 107 M-1s-1), like glutathione (k = 1.2 x 108 M-1s-1), yielding seleninic and selenonic acid derivatives, and it also decreased HOCl formation by activated human neutrophils (IC50=4.6 μM) and purified myeloperoxidase (MPO) (IC50=3.8 μM). However, tyrosine, MPO-I and MPO-II substrates, did not restore HOCl formation in presence of DD. DD inhibited the oxidative burst in dHL-60 cells with no toxicity up to 25 µM for 48h. Next, an intraperitoneal administration of 25, 50, and 75 mg/kg DD decreased total leukocyte, neutrophil chemotaxis, and inflammation markers (MPO activity, lipid peroxidation, albumin exudation, nitrite, TNF-α, IL-1β, CXCL1/KC, and CXCL2/MIP-2) on a murine model of carrageenan-induced peritonitis. Likewise, 50 mg/kg DD (i.p.) decreased carrageenan-induced paw edema over 5h. Histological and immunohistochemistry analyses of the paw tissue showed decreased neutrophil count, edema area, and MPO, carbonylated, and nitrated protein staining. Furthermore, DD treatment decreased the fMLP-induced chemotaxis of human neutrophils (IC50=3.7 μM) in vitro with no toxicity. Lastly, DD presented no toxicity in a single-dose model using mice (50 mg/kg, i.p.) over 15 days and in Artemia salina bioassay (50 to 2000 µM), corroborating findings from in silico toxicological study. Altogether, these results demonstrate that DD attenuates carrageenan-induced inflammation mainly by reducing neutrophil migration and the resulting damage from MPO-mediated oxidative burst.
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Affiliation(s)
- Tássia Liz Araújo Dos Santos Lessa
- Programa Multicêntrico de Pós-Graduação em Bioquímica e Biologia Molecular, Universidade Estadual do Sudoeste da Bahia, Vitória da Conquista, Brazil
| | - Thiago Macêdo Lopes Correia
- Programa de Pós-Graduação Multicêntrico em Ciências Fisiológicas, Universidade Federal da Bahia, Vitória da Conquista, Brazil
| | - Talita Costa Dos Santos
- Programa de Pós-Graduação Multicêntrico em Ciências Fisiológicas, Universidade Federal da Bahia, Vitória da Conquista, Brazil
| | | | | | - Maria Cláudia Magalhães Cavallini
- Center for Research in Inflammatory Diseases, Department of Pharmacology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Leonardo Silva Rocha
- Programa Multicêntrico de Pós-Graduação em Bioquímica e Biologia Molecular, Universidade Estadual do Sudoeste da Bahia, Vitória da Conquista, Brazil
| | | | | | - Gustavo Cervi
- Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | - Thiago C Correra
- Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | | | | | - Thiago Mattar Cunha
- Center for Research in Inflammatory Diseases, Department of Pharmacology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Regiane Yatsuda
- Programa de Pós-Graduação Multicêntrico em Ciências Fisiológicas, Universidade Federal da Bahia, Vitória da Conquista, Brazil
- Instituto Multidisciplinar de Saúde, Universidade Federal da Bahia, Vitória da Conquista, Brazil
| | - Amélia Cristina Mendes de Magalhães
- Programa de Pós-Graduação Multicêntrico em Ciências Fisiológicas, Universidade Federal da Bahia, Vitória da Conquista, Brazil
- Instituto Multidisciplinar de Saúde, Universidade Federal da Bahia, Vitória da Conquista, Brazil
| | | | | | - Raphael Ferreira Queiroz
- Programa Multicêntrico de Pós-Graduação em Bioquímica e Biologia Molecular, Universidade Estadual do Sudoeste da Bahia, Vitória da Conquista, Brazil
- Departamento de Ciências da Saúde, Universidade Estadual do Sudoeste da Bahia, Vitória da Conquista, Brazil
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Ribeiro FWM, Omari I, Thomas GT, Paul M, Williams PJH, McIndoe JS, Correra TC. Microstructural Analysis of Benzoxazine Cationic Ring-Opening Polymerization Pathways. Macromol Rapid Commun 2024; 45:e2300470. [PMID: 37716013 DOI: 10.1002/marc.202300470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 09/06/2023] [Indexed: 09/18/2023]
Abstract
Herein, an evaluation of the initial step of benzoxazine polymerization is presented by mass spectrometry, with a focus on differentiating the phenoxy and phenolic products formed by distinct pathways of the cationic ring opening polymerization (ROP) mechanism of polybenzoxazine formation. The use of infrared multiple photon dissociation (IRMPD) and ion mobility spectrometry (IMS) techniques allows for differentiation of the two pathways and provides valuable insights into the ROP mechanism. The results suggest that type I pathway is favored in the initial stages of the reaction yielding the phenoxy product, while type II product should be observed at later stages when the phenoxy product would interconvert to the most stable type II phenolic product. Overall, the findings presented here provide important information on the initial step of the benzoxazine polymerization, allowing the development of optimal polymerization conditions and represents a way to evaluate other multifunctional polymerization processes.
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Affiliation(s)
- Francisco W M Ribeiro
- Department of Fundamental Chemistry, Institute of Chemistry, University of São Paulo, Av. Prof. Lineu Prestes, 748, Cidade Universitária, São Paulo, SP, 05508-000, Brazil
| | - Isaac Omari
- Department of Chemistry, University of Victoria, P. O. Box 3065, Victoria, BC V8W 3V6, Canada
| | - Gilian T Thomas
- Department of Chemistry, University of Victoria, P. O. Box 3065, Victoria, BC V8W 3V6, Canada
| | - Mathias Paul
- Department of Chemistry, University of Victoria, P. O. Box 3065, Victoria, BC V8W 3V6, Canada
| | - Peter J H Williams
- Department of Chemistry, University of Victoria, P. O. Box 3065, Victoria, BC V8W 3V6, Canada
| | - J Scott McIndoe
- Department of Chemistry, University of Victoria, P. O. Box 3065, Victoria, BC V8W 3V6, Canada
| | - Thiago C Correra
- Department of Fundamental Chemistry, Institute of Chemistry, University of São Paulo, Av. Prof. Lineu Prestes, 748, Cidade Universitária, São Paulo, SP, 05508-000, Brazil
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Fernandes AS, Obeid G, Laureno TJN, Correra TC. Protonated and Sodiated Cyclophosphamide Fragmentation Pathways Evaluation by Infrared Multiple Photon Dissociation Spectroscopy. J Phys Chem A 2023. [PMID: 37285455 DOI: 10.1021/acs.jpca.3c01323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Cyclophosphamide (CP or CTX) is a widely used antineoplastic agent, and the evaluation of its efficacy and its impacts on the environment are dependent on tandem mass spectrometry (MSn) techniques. Because there is no dedicated experimental study to characterize the actual molecular nature of the CP fragments upon collision-induced dissociation, this work evaluated the chemical structure of the fragments of protonated and sodiated CP and CP protonation sites by infrared multiple photon dissociation spectroscopy supported by density functional theory calculations. This study allowed us to propose a new fragment structure and confirm the nature of multiple fragments, including those relevant for transitions used for CP quantitative and qualitative analyses. Our results also show that there is no spectroscopic evidence that can rule out the existence of aziridinium fragments, making it clear that further studies on the nature of iminium/aziridinium fragments in the gas phase are necessary.
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Affiliation(s)
- André S Fernandes
- Department of Fundamental Chemistry, Institute of Chemistry, University of São Paulo, Av. Prof. Lineu Prestes, 748, Cidade Universitária, São Paulo 05508-000, São Paulo, Brazil
| | - Guilherme Obeid
- Department of Fundamental Chemistry, Institute of Chemistry, University of São Paulo, Av. Prof. Lineu Prestes, 748, Cidade Universitária, São Paulo 05508-000, São Paulo, Brazil
| | - Tiago J N Laureno
- Department of Fundamental Chemistry, Institute of Chemistry, University of São Paulo, Av. Prof. Lineu Prestes, 748, Cidade Universitária, São Paulo 05508-000, São Paulo, Brazil
| | - Thiago C Correra
- Department of Fundamental Chemistry, Institute of Chemistry, University of São Paulo, Av. Prof. Lineu Prestes, 748, Cidade Universitária, São Paulo 05508-000, São Paulo, Brazil
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Obeid G, Moraes GO, Penna TC, Schenberg LA, Ducati LC, Correra TC. Solvation effects on glyphosate protonation and deprotonation states evaluated by mass spectrometry and explicit solvation simulations. J Chem Phys 2023; 158:054306. [PMID: 36754805 DOI: 10.1063/5.0134003] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Glyphosate is a widely used herbicide, and its protonation and deprotonation sites are fundamental to understanding its properties. In this work, the sodiated, protonated, and deprotonated glyphosate were evaluated in the gas phase by infrared multiple photon dissociation spectroscopy to determine the exact nature of these coordination, protonation, and deprotonation states in the gas phase. In this context, Natural Bond Orbital analyses were carried out to unravel interactions that govern glyphosate (de)protonation states in the gas phase. The solvent effect on the protonation/deprotonation equilibria was also investigated by implicit (Solvation Model Based on Density and polarizable continuum models) and explicit solvation models (Monte Carlo and Molecular Dynamics simulations). These results show that glyphosate is protonated in the phosphonate group in the gas phase because of the strong hydrogen bond between the carboxylic oxygen (O7) and the protonated phosphonate group (O8-H19), while the most stable species in water is protonated at the amino group because of the preferential interaction of the NH2 + group and the solvent water molecules. Similarly, deprotonated glyphosate [Glyp-H]- was shown to be deprotonated at the phosphonate group in the gas phase but not in solution, also because of the preferential solvation of the NH2 + group present in the other deprotomers. Therefore, these results show that the stabilization of the protonated amino group by the solvent molecules is the governing factor of the (de)protonation equilibrium of glyphosate in water.
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Affiliation(s)
- Guilherme Obeid
- Department of Fundamental Chemistry, Institute of Chemistry-University of São Paulo, Av. Prof. Lineu Prestes, 748, Cidade Universitária, São Paulo, SP, Brazil
| | - Gustavo O Moraes
- Department of Fundamental Chemistry, Institute of Chemistry-University of São Paulo, Av. Prof. Lineu Prestes, 748, Cidade Universitária, São Paulo, SP, Brazil
| | - Tatiana C Penna
- Department of Fundamental Chemistry, Institute of Chemistry-University of São Paulo, Av. Prof. Lineu Prestes, 748, Cidade Universitária, São Paulo, SP, Brazil
| | - Leonardo A Schenberg
- Department of Fundamental Chemistry, Institute of Chemistry-University of São Paulo, Av. Prof. Lineu Prestes, 748, Cidade Universitária, São Paulo, SP, Brazil
| | - Lucas C Ducati
- Department of Fundamental Chemistry, Institute of Chemistry-University of São Paulo, Av. Prof. Lineu Prestes, 748, Cidade Universitária, São Paulo, SP, Brazil
| | - Thiago C Correra
- Department of Fundamental Chemistry, Institute of Chemistry-University of São Paulo, Av. Prof. Lineu Prestes, 748, Cidade Universitária, São Paulo, SP, Brazil
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Batista PR, Penna TC, Ducati LC, Correra TC. p-Aminobenzoic acid protonation dynamics in an evaporating droplet by ab initio molecular dynamics. Phys Chem Chem Phys 2021; 23:19659-19672. [PMID: 34524295 DOI: 10.1039/d1cp01495a] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Protonation equilibria are known to vary from the bulk to microdroplet conditions, which could induce many chemical and physical phenomena. Protonated p-aminobenzoic acid (PABA + H+) can be considered a model for probing the protonation dynamics in an evaporating droplet, as its protonation equilibrium is highly dependent on the formation conditions from solution via atmospheric pressure ionization sources. Experiments using diverse experimental techniques have shown that protic solvents allow formation of the O-protomer (PABA protonated in the carboxylic acid group) stable in the gas phase, while aprotic solvents yield the N-protomer (protonated in the amino group) that is the most stable protomer in solution. In this work, we explore the protonation equilibrium of PABA solvated by different numbers of water molecules (n = 0 to 32) using ab initio molecular dynamics. For n = 8-32, the protonation is either at the NH2 group or in the solvent network. The solvent network interacts with the carboxylic acid group, but there is no complete proton transfer to form the O-protomer. For smaller clusters, however, solvent-mediated proton transfers to the carboxylic acid were observed, both via the Grotthuss mechanism and the vehicle or shuttle mechanism (for n = 1 and 2). Thermodynamic considerations allowed a description of the origins of the kinetic trapping effect, which explains the observation of the solution structure in the gas phase. This effect likely occurs in the final evaporation steps, which are outside the droplet size range covered by previous classical molecular dynamics simulations of charged droplets. These results may be considered relevant in determining the nature of the species observed in the ubiquitous ESI based mass spectrometry analysis, and in general for droplet chemistry, explaining how protonation equilibria are drastically changed from bulk to microdroplet conditions.
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Affiliation(s)
- Patrick R Batista
- Department of Fundamental Chemistry, Institute of Chemistry - University of São Paulo, Av. Prof. Lineu Prestes, 748, Cidade Universitária, São Paulo, SP, Brazil.
| | - Tatiana C Penna
- Department of Fundamental Chemistry, Institute of Chemistry - University of São Paulo, Av. Prof. Lineu Prestes, 748, Cidade Universitária, São Paulo, SP, Brazil.
| | - Lucas C Ducati
- Department of Fundamental Chemistry, Institute of Chemistry - University of São Paulo, Av. Prof. Lineu Prestes, 748, Cidade Universitária, São Paulo, SP, Brazil.
| | - Thiago C Correra
- Department of Fundamental Chemistry, Institute of Chemistry - University of São Paulo, Av. Prof. Lineu Prestes, 748, Cidade Universitária, São Paulo, SP, Brazil.
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Penna TC, Cervi G, Rodrigues-Oliveira AF, Yamada BD, Lima RZC, Menegon JJ, Bastos EL, Correra TC. Development of a photoinduced fragmentation ion trap for infrared multiple photon dissociation spectroscopy. Rapid Commun Mass Spectrom 2020; 34 Suppl 3:e8635. [PMID: 31677291 DOI: 10.1002/rcm.8635] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Revised: 10/07/2019] [Accepted: 10/08/2019] [Indexed: 06/10/2023]
Abstract
RATIONALE Methods for isomer discrimination by mass spectroscopy are of increasing interest. Here we describe the development of a three-dimensional ion trap for infrared multiple photon dissociation (IRMPD) spectroscopy that enables the acquisition of the infrared spectrum of selected ions in the gas phase. This system is suitable for the study of a myriad of chemical systems, including isomer mixtures. METHODS A modified three-dimensional ion trap was coupled to a CO2 laser and an optical parametric oscillator/optical parametric amplifier (OPO/OPA) system operating in the range 2300 to 4000 cm-1 . Density functional theory vibrational frequency calculations were carried out to support spectral assignments. RESULTS Detailed descriptions of the interface between the laser and the mass spectrometer, the hardware to control the laser systems, the automated system for IRMPD spectrum acquisition and data management are presented. The optimization of the crystal position of the OPO/OPA system to maximize the spectroscopic response under low-power laser radiation is also discussed. CONCLUSIONS OPO/OPA and CO2 laser-assisted dissociation of gas-phase ions was successfully achieved. The system was validated by acquiring the IRMPD spectra of model species and comparing with literature data. Two isomeric alkaloids of high economic importance were characterized to demonstrate the potential of this technique, which is now available as an open IRMPD spectroscopy facility in Brazil.
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Affiliation(s)
- Tatiana C Penna
- Department of Fundamental Chemistry, Institute of Chemistry, University of São Paulo, Av. Prof. Lineu Prestes 748, 05508-000, São Paulo, SP, Brazil
| | - Gustavo Cervi
- Department of Fundamental Chemistry, Institute of Chemistry, University of São Paulo, Av. Prof. Lineu Prestes 748, 05508-000, São Paulo, SP, Brazil
| | - André F Rodrigues-Oliveira
- Department of Fundamental Chemistry, Institute of Chemistry, University of São Paulo, Av. Prof. Lineu Prestes 748, 05508-000, São Paulo, SP, Brazil
| | - Bruno D Yamada
- Department of Fundamental Chemistry, Institute of Chemistry, University of São Paulo, Av. Prof. Lineu Prestes 748, 05508-000, São Paulo, SP, Brazil
| | - Rafael Z C Lima
- Department of Fundamental Chemistry, Institute of Chemistry, University of São Paulo, Av. Prof. Lineu Prestes 748, 05508-000, São Paulo, SP, Brazil
| | - Jair J Menegon
- Department of Fundamental Chemistry, Institute of Chemistry, University of São Paulo, Av. Prof. Lineu Prestes 748, 05508-000, São Paulo, SP, Brazil
| | - Erick L Bastos
- Department of Fundamental Chemistry, Institute of Chemistry, University of São Paulo, Av. Prof. Lineu Prestes 748, 05508-000, São Paulo, SP, Brazil
| | - Thiago C Correra
- Department of Fundamental Chemistry, Institute of Chemistry, University of São Paulo, Av. Prof. Lineu Prestes 748, 05508-000, São Paulo, SP, Brazil
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Rodrigues-Oliveira AF, Batista PR, Ducati LC, Correra TC. Analyzing the N–H+…π interactions of protonated tryptophan and phenylalkylamines using QTAIM, NCI, and NBO. Theor Chem Acc 2020. [DOI: 10.1007/s00214-020-02643-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Oliveira IM, Esteves HA, Darbem MP, Sartorelli A, Correra TC, Rodrigues‐Oliveira AF, Pimenta DC, Zukerman‐Schpector J, Manarin F, Stefani HA. Stereo‐ and Regioselective Cu‐Catalyzed Hydroboration of Alkynyl Chalcogenoethers. ChemCatChem 2020. [DOI: 10.1002/cctc.202000395] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Isadora M. Oliveira
- Departamento de Química FundamentalInstituto de QuímicaUniversidade de São Paulo São Paulo, postal code missing SP Brazil
| | - Henrique A. Esteves
- Departamento de FarmáciaFaculdade de Ciências FarmacêuticasUniversidade de São Paulo São Paulo SP postal code missing SP Brazil
| | - Mariana P. Darbem
- Departamento de FarmáciaFaculdade de Ciências FarmacêuticasUniversidade de São Paulo São Paulo SP postal code missing SP Brazil
| | - Arthur Sartorelli
- Departamento de FarmáciaFaculdade de Ciências FarmacêuticasUniversidade de São Paulo São Paulo SP postal code missing SP Brazil
| | - Thiago C. Correra
- Departamento de Química FundamentalInstituto de QuímicaUniversidade de São Paulo São Paulo, postal code missing SP Brazil
| | - André F. Rodrigues‐Oliveira
- Departamento de Química FundamentalInstituto de QuímicaUniversidade de São Paulo São Paulo, postal code missing SP Brazil
| | | | - Julio Zukerman‐Schpector
- Departamento de QuímicaUniversidade Federal de São Carlos São Carlos SP postal code missing SP Brazil
| | - Flávia Manarin
- Centro de Engenharias e Ciências Exatas – CECEUniversidade Estadual do Oeste do Paraná Toledo PR postal code missing SP Brazil
| | - Hélio A. Stefani
- Departamento de FarmáciaFaculdade de Ciências FarmacêuticasUniversidade de São Paulo São Paulo SP postal code missing SP Brazil
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Tavares LC, Penna TC, Johnson M, Correra TC. Evaluation of protonation sites in two MacMillan catalysts in solution by gas phase predissociation spectroscopy and electronic structure calculations. ARKIVOC 2020. [DOI: 10.24820/ark.5550190.p011.148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Correra TC, Quina FH. A tribute to Professor José Manuel Riveros. ARKIVOC 2019. [DOI: 10.24820/ark.5550190.p001.477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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M Ribeiro FW, Rodrigues-Oliveira AF, C Correra T. Benzoxazine Formation Mechanism Evaluation by Direct Observation of Reaction Intermediates. J Phys Chem A 2019; 123:8179-8187. [PMID: 31483645 DOI: 10.1021/acs.jpca.9b05065] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Benzoxazine formation is a fundamental step in the preparation of polybenzoxazine resins, and a detailed description of the mechanism governing the formation of benzoxazine and side products is vital for improving the properties and performance of these resins. Determination of the nature and properties of reaction intermediates is not trivial. Therefore, a Mannich-type condensation of aniline, formaldehyde, and phenol was evaluated as a potential method to form benzoxazine. Coupling positive mode electrospray ionization mass spectrometry (ESI(+)-MS) with infrared multiple photon dissociation (IRMPD) spectroscopy allowed unambiguous determination of an iminium-based mechanism and the direct observation of iminium intermediates. The benzoxazine formation mechanism was indirectly confirmed by the observation of side products that are relevant to the polymerization step, and directly confirmed by the identification of four distinct reaction intermediates that were completely characterized by IRMPD spectroscopy. The benzoxazine monomer was also shown to undergo isomerization under standard ESI-MS analysis conditions, suggesting the presence of a mixture of three isomers during their usual ESI-MS analysis.
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Affiliation(s)
- Francisco W M Ribeiro
- Department of Fundamental Chemistry, Institute of Chemistry , University of São Paulo Av. Prof. Lineu Prestes, 748, Cidade Universitária , São Paulo , São Paulo 05508-000 , Brazil
| | - André F Rodrigues-Oliveira
- Department of Fundamental Chemistry, Institute of Chemistry , University of São Paulo Av. Prof. Lineu Prestes, 748, Cidade Universitária , São Paulo , São Paulo 05508-000 , Brazil
| | - Thiago C Correra
- Department of Fundamental Chemistry, Institute of Chemistry , University of São Paulo Av. Prof. Lineu Prestes, 748, Cidade Universitária , São Paulo , São Paulo 05508-000 , Brazil
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Tripodi GL, Correra TC, Angolini CFF, Ferreira BRV, Maître P, Eberlin MN, Roithová J. The Intermediates in Lewis Acid Catalysis with Lanthanide Triflates. European J Org Chem 2019; 2019:3560-3566. [PMID: 31680777 PMCID: PMC6813638 DOI: 10.1002/ejoc.201900171] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Indexed: 01/27/2023]
Abstract
Lanthanide triflates are effective Lewis acid catalysts in reactions involving carbonyl compounds due to their high oxophilicity and water stability. Despite the growing interest, the identity of the catalytic species formed in lanthanide catalysed reactions is still unknown. We have therefore used mass spectrometry and ion spectroscopy to intercept and characterize the intermediates in a reaction catalysed by ytterbium and dysprosium triflates. We were able to identify a number of lanthanide intermediates formed in a simple condensation reaction between a C‐acid and an aldehyde. Results show correlation between the reactivity of lanthanide complexes and their charge state and suggest that the triply charged complexes play a key role in lanthanide catalysed reactions. Spectroscopic data of the gaseous ions accompanied by theoretical calculations reveal that the difference between catalytic efficiencies of ytterbium and dysprosium ions can be explained by their different electrophilicity.
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Affiliation(s)
- Guilherme L Tripodi
- Institute for Molecules and Materials Radboud University Heyendaalseweg 135 6525 AJ Nijmegen The Netherlands
| | - Thiago C Correra
- Departament of Organic Chemistry Institute of Chemistry University of São Paulo 05508-000 São Paulo-SP Brazil
| | - Célio F F Angolini
- Center for Natural and Human Sciences Federal University of ABC (UFABC) 09210-580 Santo André -SP Brazil
| | - Bruno R V Ferreira
- Instituto Federal do Norte de Minas Gerais Campus Salinas 39560-000 Salinas-MG Brazil
| | - Philippe Maître
- Laboratoire de Chimie Physique, URM8000, CNRS, Univ. Paris-Sud Université Paris-Saclay 91405 Orsay France
| | - Marcos N Eberlin
- ThoMSon Mass Spectrometry Laboratory, Institute of Chemistry State University of Campinas 13084-971 Campinas-SP Brazil.,School of Engeneering Mackenzie Presbiterian University 01302907 São Paulo-SP Brazil
| | - Jana Roithová
- Institute for Molecules and Materials Radboud University Heyendaalseweg 135 6525 AJ Nijmegen The Netherlands
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Tripodi GL, Correra TC, Angolini CFF, Ferreira BRV, Maître P, Eberlin MN, Roithová J. Cover Feature: The Intermediates in Lewis Acid Catalysis with Lanthanide Triflates (Eur. J. Org. Chem. 22/2019). European J Org Chem 2019. [DOI: 10.1002/ejoc.201900756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Guilherme L. Tripodi
- Institute for Molecules and Materials; Radboud University; Heyendaalseweg 135 6525 AJ Nijmegen The Netherlands
| | - Thiago C. Correra
- Departament of Organic Chemistry; Institute of Chemistry; University of São Paulo; 05508-000, São Paulo-SP Brazil
| | - Célio F. F. Angolini
- Center for Natural and Human Sciences; Federal University of ABC (UFABC); 09210-580, Santo André -SP Brazil
| | - Bruno R. V. Ferreira
- Campus Salinas; Instituto Federal do Norte de Minas Gerais; 39560-000, Salinas-MG Brazil
| | - Philippe Maître
- Laboratoire de Chimie Physique, URM8000, CNRS, Univ. Paris-Sud; Université Paris-Saclay; 91405, Orsay France
| | - Marcos N. Eberlin
- ThoMSon Mass Spectrometry Laboratory; Institute of Chemistry; State University of Campinas; 13084-971, Campinas-SP Brazil
- School of Engeneering; Mackenzie Presbiterian University; 01302907, São Paulo-SP Brazil
| | - Jana Roithová
- Institute for Molecules and Materials; Radboud University; Heyendaalseweg 135 6525 AJ Nijmegen The Netherlands
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14
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Masson MAC, Karpfenstein R, de Oliveira-Silva D, Teuler JM, Archirel P, Maître P, Correra TC. Evaluation of Ca2+ Binding Sites in Tacrolimus by Infrared Multiple Photon Dissociation Spectroscopy. J Phys Chem B 2018; 122:9860-9868. [DOI: 10.1021/acs.jpcb.8b06523] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Maria Angélica C. Masson
- Department of Fundamental Chemistry, Institute of Chemistry, University of São Paulo, Av. Prof. Lineu Prestes, 748, 05508-000 São Paulo, São Paulo, Brazil
| | - Renan Karpfenstein
- Department of Chemistry, Institute of Environmental, Chemical and Pharmaceutical Sciences, Federal University of São Paulo, St. Prof. Arthur Riedel 275, 09972-270 Diadema, São Paulo, Brazil
| | - Diogo de Oliveira-Silva
- Department of Chemistry, Institute of Environmental, Chemical and Pharmaceutical Sciences, Federal University of São Paulo, St. Prof. Arthur Riedel 275, 09972-270 Diadema, São Paulo, Brazil
| | - Jean-Marie Teuler
- Laboratoire de Chimie Physique, URM8000, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91405 Orsay, France
| | - Pierre Archirel
- Laboratoire de Chimie Physique, URM8000, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91405 Orsay, France
| | - Philippe Maître
- Laboratoire de Chimie Physique, URM8000, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91405 Orsay, France
| | - Thiago C. Correra
- Department of Fundamental Chemistry, Institute of Chemistry, University of São Paulo, Av. Prof. Lineu Prestes, 748, 05508-000 São Paulo, São Paulo, Brazil
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15
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Rodrigues-Oliveira AF, M. Ribeiro FW, Cervi G, C. Correra T. Evaluation of Common Theoretical Methods for Predicting Infrared Multiphotonic Dissociation Vibrational Spectra of Intramolecular Hydrogen-Bonded Ions. ACS Omega 2018; 3:9075-9085. [PMID: 31459042 PMCID: PMC6644661 DOI: 10.1021/acsomega.8b00815] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 07/25/2018] [Indexed: 05/25/2023]
Abstract
Infrared photodissociation analyses are supported by theoretical calculations that allow a trustworthy interpretation of experimental spectra of gaseous ions. B3LYP calculations are the most prominent method used to model IR spectra, as detailed in our bibliographic survey. However, this and other commonly used methods are known to provide inaccurate energy values and geometries, especially when it comes to long-range interactions, such as intramolecular H-bonds, which show increased anharmonicity. Therefore, we evaluated some of the most commonly used density functional theory methods (B3LYP, CAM-B3LYP, and M06-2X) and basis sets (6-31+G(d,p), 6-311++G(d,p), 6-311++G(3df,2pd), aug-cc-pVDZ, and aug-cc-pVTZ), including anharmonicity and dispersion corrections. The results were compared to MP2 calculations and to experimental high-frequency (2000-4000 cm-1) IR multiphotonic dissociation (IRMPD) spectra of two protonated model molecules containing intramolecular hydrogen bonds: biotin and tryptophan. M06-2X/6-31+G(d,p) was shown to be the most cost-effective level of theory, whereas CAM-B3LYP was the most efficient method to describe the van der Waals interactions. The use of the dispersion correction D3, proposed by Grimme, improved the description of O-H vibrations involved in H-bonding but worsened the description of N-H stretches. Anharmonic calculations were shown to be extremely expensive when compared to other approaches. The efficiencies of well-established scaling factors (SFs) in opposition to sample-dependent SFs were also discussed and the use of fitted SFs were shown to be the most cost-effective approach to predict IRMPD spectra. M06-2X/6-31+G(d,p) and CAM-B3LYP/aug-cc-pVDZ were also tested against the fingerprint region. Our results suggest that these methods can also be used for analysis in this lower frequency range and should be regarded as the methods of choice for cost-effective IRMPD simulations rather than the ubiquitous B3LYP method, especially when further molecular properties are needed.
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Affiliation(s)
- André F. Rodrigues-Oliveira
- Department of Fundamental Chemistry, Institute of Chemistry, University of São Paulo, Avenue Prof. Lineu Prestes, 748, 05508-000 São Paulo, Brazil
| | - Francisco W. M. Ribeiro
- Department of Fundamental Chemistry, Institute of Chemistry, University of São Paulo, Avenue Prof. Lineu Prestes, 748, 05508-000 São Paulo, Brazil
| | - Gustavo Cervi
- Department of Fundamental Chemistry, Institute of Chemistry, University of São Paulo, Avenue Prof. Lineu Prestes, 748, 05508-000 São Paulo, Brazil
| | - Thiago C. Correra
- Department of Fundamental Chemistry, Institute of Chemistry, University of São Paulo, Avenue Prof. Lineu Prestes, 748, 05508-000 São Paulo, Brazil
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16
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Esteves LC, Pinheiro AC, Pioli RM, Penna TC, Baader WJ, Correra TC, Bastos EL. Revisiting the Mechanism of Hydrolysis of Betanin. Photochem Photobiol 2018; 94:853-864. [PMID: 29412460 DOI: 10.1111/php.12897] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 01/02/2018] [Indexed: 11/28/2022]
Abstract
Betanin (betanidin 5-O-β-D-glucoside) is a water-soluble plant pigment used as a color additive in food, drugs and cosmetic products. Despite its sensitivity to light and heat, betanin maintains appreciable tinctorial strength in low acidic and neutral conditions, where the color of other plant pigments, such as anthocyanins, quickly fades. However, betanin is an iminium natural product that experiences acid- and base-catalyzed hydrolysis to form the fairly stable betalamic acid and cyclo-DOPA-5-O-β-D-glucoside. Here, we show that the decomposition of betanin in aqueous phosphate solution pH 2-11 is subject to general base catalysis by hydrogen phosphate ion and intramolecular general acid and base catalysis, providing new insights on the mechanism of betanin hydrolysis. UV/Vis absorption spectrophotometry, 1 H NMR spectroscopy and mass spectrometry were used to investigate product formation. Furthermore, theoretical calculations support the hypothesis that the nitrogen atom of the tetrahydropyridine ring of betanin is doubly protonated, as observed for structurally simpler amino dicarboxylic acids. Our results contribute to the study of betanin and other pigments belonging to the class of betalains and to deepen the knowledge on the chemical properties of imino acids as well as on iminium-catalyzed modifications of carbonyl compounds in water.
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Affiliation(s)
- Larissa C Esteves
- Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Amanda C Pinheiro
- Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Renan M Pioli
- Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Tatiana C Penna
- Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Wilhelm J Baader
- Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Thiago C Correra
- Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Erick L Bastos
- Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
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17
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Souza DHP, Guimarães RR, Correra TC, Zamarion VM. Investigation of the photocatalytic activity of titanium dioxide films under visible light measured by electrospray mass spectrometry. NEW J CHEM 2018. [DOI: 10.1039/c8nj04047h] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Pure TiO2 P-25 films demonstrate effective photodegradation activity of organic pollutants under the incidence of visible light observed via ESI(−)-MS.
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Affiliation(s)
- Diego H. P. Souza
- Departamento de Química Fundamental
- Instituto de Química da Universidade de São Paulo
- São Paulo
- Brazil
| | - Robson R. Guimarães
- Departamento de Química Fundamental
- Instituto de Química da Universidade de São Paulo
- São Paulo
- Brazil
| | - Thiago C. Correra
- Departamento de Química Fundamental
- Instituto de Química da Universidade de São Paulo
- São Paulo
- Brazil
| | - Vitor M. Zamarion
- Departamento de Química Fundamental
- Instituto de Química da Universidade de São Paulo
- São Paulo
- Brazil
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18
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Princival C, Archilha MVLR, Dos Santos AA, Franco M, Braga AAC, Rodrigues-Oliveira AF, Correra TC, Cunha RLOR, Comasseto JV. Stability Study of Hypervalent Tellurium Compounds in Aqueous Solutions. ACS Omega 2017; 2:4431-4439. [PMID: 31457735 PMCID: PMC6641895 DOI: 10.1021/acsomega.7b00628] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 07/19/2017] [Indexed: 06/10/2023]
Abstract
Hypervalent tellurium compounds (telluranes) are promising therapeutical agents with negligible toxicities for some diseases in animal models. The C-Te bond of organotellurium compounds is commonly considered unstable, disfavoring their applicability in biological studies. In this study, the stability of a set of telluranes composed of an inorganic derivative and noncharged and charged organic derivatives was monitored in aqueous media with 1H, 13C, and 125Te NMR spectroscopy and high-resolution mass spectrometry. Organic telluranes were found to be remarkably resistant and stable to hydrolysis, whereas the inorganic tellurane AS101 is totally converted to the hydrolysis product, trichlorooxytellurate, [TeOCl 3 ]-, which was also observed in the hydrolysis of TeCl 4 . The noteworthy stability of organotelluranes in aqueous media makes them prone to further structure-activity relationship studies and to be considered for broad biological investigations.
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Affiliation(s)
| | | | | | - Maurício
P. Franco
- Instituto
de Química, Universidade de São
Paulo, São
Paulo, SP 05508-020, Brazil
| | - Ataualpa A. C. Braga
- Instituto
de Química, Universidade de São
Paulo, São
Paulo, SP 05508-020, Brazil
| | | | - Thiago C. Correra
- Instituto
de Química, Universidade de São
Paulo, São
Paulo, SP 05508-020, Brazil
| | - Rodrigo L. O. R. Cunha
- Centro
de Ciências Naturais e Humanas, Universidade
Federal do ABC, Santo André, SP 09210-580, Brazil
| | - João V. Comasseto
- Instituto
de Química, Universidade de São
Paulo, São
Paulo, SP 05508-020, Brazil
- Instituto
de Ciências Ambientais, Químicas e Farmacêuticas, Universidade Federal de São Paulo, Diadema, SP 04021-001, Brazil
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19
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de Oliveira IM, Vasconcelos SSN, Barbeiro CS, Correra TC, Shamim A, Pimenta DC, Caracelli I, Zukerman-Schpector J, Stefani HA, Manarin F. Ytterbium(iii)-catalyzed three-component reactions: synthesis of 4-organoselenium-quinolines. NEW J CHEM 2017. [DOI: 10.1039/c7nj01803g] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
4-Organoselenium-quinolines were synthesized via model multi-component Povarov reactions between p-anisidine, ethyl glyoxylate and ethynyl(phenyl)selane.
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Affiliation(s)
| | | | - Cristiane S. Barbeiro
- Departamento de Farmácia
- Faculdade de Ciências Farmacêuticas
- Universidade de São Paulo
- São Paulo
- Brazil
| | | | - Anwar Shamim
- Instituto de Química
- Universidade de São Paulo
- São Paulo
- Brazil
| | | | - Ignez Caracelli
- Departmento de Física
- Universidade Federal de São Carlos
- São Carlos
- Brazil
| | | | - Hélio A. Stefani
- Departamento de Farmácia
- Faculdade de Ciências Farmacêuticas
- Universidade de São Paulo
- São Paulo
- Brazil
| | - Flávia Manarin
- Centro de Engenharias e Ciências Exatas-CECE
- Universidade Estadual do Oeste do Paraná
- Toledo
- Brazil
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20
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Barbeiro CS, Vasconcelos SNS, Zukerman-Schpector J, Caracelli I, Pimenta DC, Rodrigues ACB, Fernandes AS, Correra TC, Bastos EL, Stefani HA. Chlorinated 2-hydroxynaphthalenoxazolines: Synthesis, Reaction Mechanism and Fluorescence Properties. ChemistrySelect 2016. [DOI: 10.1002/slct.201601526] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Cristiane S. Barbeiro
- Departamento de Farmácia, Faculdade de Ciências Farmacêuticas; Universidade de São Paulo; São Paulo, SP Brazil
| | - Stanley N. S. Vasconcelos
- Departamento de Farmácia, Faculdade de Ciências Farmacêuticas; Universidade de São Paulo; São Paulo, SP Brazil
| | - Júlio Zukerman-Schpector
- Laboratório de Cristalografia, Estereodinâmica e Modelagem Molecular, Departamento de Química; Universidade Federal de São Carlos; São Carlos, SP Brazil
| | - Ignez Caracelli
- BioMat-Departamento de Física; Universidade Federal de São Carlos; São Carlos, SP Brazil
| | - Daniel C. Pimenta
- Departamento de Bioquímica e Biofísica; Instituto Butantã; São Paulo, SP Brazil
| | - Ana Clara B. Rodrigues
- Departamento de Química Fundamental, Instituto de Química; Universidade de São Paulo; São Paulo, SP Brazil
| | - André S. Fernandes
- Departamento de Química Fundamental, Instituto de Química; Universidade de São Paulo; São Paulo, SP Brazil
| | - Thiago C. Correra
- Departamento de Química Fundamental, Instituto de Química; Universidade de São Paulo; São Paulo, SP Brazil
| | - Erick L. Bastos
- Departamento de Química Fundamental, Instituto de Química; Universidade de São Paulo; São Paulo, SP Brazil
| | - Hélio A. Stefani
- Departamento de Farmácia, Faculdade de Ciências Farmacêuticas; Universidade de São Paulo; São Paulo, SP Brazil
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21
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Correra TC, Fernandes AS, Riveros JM. Dynamic/Thermochemical Balance Drives Unusual Alkyl/F Exchange Reactions in Siloxides and Analogs. J Phys Chem A 2016; 120:1644-51. [PMID: 26911457 DOI: 10.1021/acs.jpca.6b00390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A recent report has shown that siloxides can undergo an unusual Me/F exchange reaction promoted by NF3 in the gas phase ( Angew. Chem. Int. Ed. 2012, 51, 8632-8635). A more extensive study of this kind of exchange has been carried out using mass spectrometry techniques (FT-ICR), DFT calculations, natural bond orbital (NBO) analysis, and Born-Oppenheimer molecular dynamics simulations (BOMD), using NF3, SO2F2, and CF4 as fluorine donors and evaluating the effect of replacing the Si center by Ge and C. This comprehensive approach shows that NF3 is crucial for the exchange reaction, as SO2F2 forms SO3F(-) via a pentacoordinated channel whereas no reaction is observed for CF4. The uniqueness of NF3 is caused by favorable thermochemical consideration and by dynamic effects that preclude the formation of the ubiquitous Si-F pentacoordinated species. Me3GeO(-) was shown to be as reactive as siloxides toward NF3, whereas C analogs showed no reactions under our experimental conditions. The exchange reaction was also shown to take place for triethylsiloxides. These exchange reactions are examples of reaction systems that avoid the lower energy pathway and are driven by dynamic effects that cannot be explained by the potential energy surface.
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Affiliation(s)
- Thiago C Correra
- Departamento de Quı́mica Fundamental, Instituto de Quı́mica, Universidade de São Paulo , São Paulo, Brazil - CEP 05508-000
| | - André S Fernandes
- Departamento de Quı́mica Fundamental, Instituto de Quı́mica, Universidade de São Paulo , São Paulo, Brazil - CEP 05508-000
| | - José M Riveros
- Departamento de Quı́mica Fundamental, Instituto de Quı́mica, Universidade de São Paulo , São Paulo, Brazil - CEP 05508-000
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22
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Qian JQ, Correra TC, Li J, Maître P, Song DQ, Hu CQ. Differentiation of cefaclor and its delta-3 isomer by electrospray mass spectrometry, infrared multiple photon dissociation spectroscopy and theoretical calculations. J Mass Spectrom 2015; 50:265-269. [PMID: 25601701 DOI: 10.1002/jms.3510] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Revised: 09/08/2014] [Accepted: 09/12/2014] [Indexed: 06/04/2023]
Affiliation(s)
- Jian-Qin Qian
- Institute of Medicinal Biotechnology, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, 100050, China; National Institutes for Food and Drug Control, Beijing, 100050, China
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23
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24
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de Souza MAF, Correra TC, Riveros JM, Longo RL. Selectivity and mechanisms driven by reaction dynamics: the case of the gas-phase OH(-) + CH3ONO2 reaction. J Am Chem Soc 2012; 134:19004-10. [PMID: 23106516 DOI: 10.1021/ja3057166] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Well-established statistical approaches such as transition-state theory based on high-level calculated potential energy profiles are unable to account for the selectivity observed in the gas-phase OH(-) + CH(3)ONO(2) reaction. This reaction can undergo bimolecular nucleophilic displacement at either the carbon center (S(N)2@C) or the nitrogen center (S(N)2@N) as well as a proton abstraction followed by dissociation (E(CO)2) pathway. Direct dynamics simulations yield an S(N)2:E(CO)2 product ratio in close agreement with experiment and show that the lack of reactivity at the nitrogen atom is due to the highly negative electrostatic potential generated by the oxygen atoms in the ONO(2) group that scatters the incoming OH(-). In addition to these dynamical effects, the nonstatistical behavior of these reactions is attributed to the absence of equilibrated reactant complexes and to the large number of recrossings, which might be present in several ion-molecule gas-phase reactions.
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Affiliation(s)
- Miguel A F de Souza
- Departamento de Química Fundamental, Universidade Federal de Pernambuco, 50.740-560 Recife, PE, Brazil
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25
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Correra TC, Riveros JM. Sequential Methyl–Fluorine Exchange Reactions of Siloxide Ions in the Gas Phase. Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201203970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Thiago C. Correra
- Instituto de Quıímica, Universidade de São Paulo, Caixa Postal 26077, São Paulo, CEP 05599‐970 (Brazil)
| | - José M. Riveros
- Instituto de Quıímica, Universidade de São Paulo, Caixa Postal 26077, São Paulo, CEP 05599‐970 (Brazil)
- Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, Rua Santa Adelia 166, Santo André, SP, CEP 09210‐170 (Brazil)
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26
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Correra TC, Riveros JM. Sequential methyl-fluorine exchange reactions of siloxide ions in the gas phase. Angew Chem Int Ed Engl 2012; 51:8632-5. [PMID: 22782656 DOI: 10.1002/anie.201203970] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2012] [Indexed: 11/12/2022]
Abstract
Exchange Me for a fluorine: Trimethylsiloxide ions in the presence of NF(3) in the gas phase undergo an unusual and sequential metathesis-type reaction wherein methyl groups are exchanged for fluorine. Theoretical calculations suggest that the reaction proceeds by a three-step internal-nucleophilic-displacement mechanism which features a pentacoordinated siliconate species as a transition state rather than as an intermediate.
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Affiliation(s)
- Thiago C Correra
- Instituto de Quıímica, Universidade de São Paulo, Caixa Postal 26077, São Paulo CEP 05599-970, Brazil
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27
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Caracelli I, Coelho DCS, Olivato PR, Correra TC, Rodrigues A, Tiekink ERT. (R)-2-Phen-oxy-1-(4-phenyl-2-sulfan-ylidene-1,3-oxazolidin-3-yl)ethanone. Acta Crystallogr Sect E Struct Rep Online 2011; 67:o2755-6. [PMID: 22065310 PMCID: PMC3201535 DOI: 10.1107/s160053681103858x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2011] [Accepted: 09/20/2011] [Indexed: 11/17/2022]
Abstract
The central 1,3-oxazolidine-2-thione ring in the title compound, C17H15NO3S, is approximately planar with maximum deviations of 0.036 (4) and −0.041 (5) Å for the O and methylene-C atoms, respectively. The dihedral angles formed between this plane and the two benzene rings, which lie to the same side of the central plane, are 86.5 (2) [ring-bound benzene] and 50.6 (3)°. The ethan-1-one residue is also twisted out of the central plane, forming a O—C—N—C torsion angle of 151.5 (5)°. The dihedral angle formed by the benzene rings is 62.8 (2)° so that overall, the molecule has a twisted U-shape. In the crystal, molecules are linked into supramolecular arrays two molecules thick in the bc plane through C—H⋯O, C—H⋯S and C—H⋯π interactions.
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28
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Abstract
There has been increasing interest in the gas-phase reactivity of alkyl nitrates because of their well-known applications as explosives and because of their role in atmospheric and in marine processes. This manuscript describes an experimental study by FT-ICR techniques of the gas-phase reactions of OH(-) and F(-) with methyl and ethyl nitrate. For methyl nitrate, the main reaction channel is found to be an elimination process promoted by abstraction of an α proton from the methyl group. Nucleophilic displacement of nitrate anion through an S(N)2 process at the carbon center is also found to be an important reaction channel with methyl nitrate. In ethyl nitrate, formation of NO(3)(-) is greatly enhanced and this is attributed to the ease of an E2-type elimination process promoted by proton abstraction at the β position of the ethyl group. Theoretical calculations at the MP2/6-311+G(3df,2p)//MP2/6-31+G(d) level of theory are consistent with the relative importance of the reaction channels and suggest that these reactions proceed through a double well potential. The calculations also predict that nucleophilic attack by OH(-) at the nitrogen center (Sn2@N) is energetically the preferred pathway but experiments with (18)OH(-) showed no evidence for this channel. Single-point calculations reveal a strong preference for approach to the carbon center and may explain the lack of reactivity at the nitrogen center. Calculations were also carried out for NH(2)(-) and SH(-) to establish the reactivity pattern to provide a better understanding of environmentally relevant nitrate esters.
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Affiliation(s)
- Thiago C Correra
- Instituto de Química, Universidade de São Paulo, Caixa Postal 26077, São Paulo, Brazil, CEP 05599-970
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29
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Prell JS, Correra TC, Chang TM, Biles JA, Williams ER. Entropy Drives an Attached Water Molecule from the C- to N-Terminus on Protonated Proline. J Am Chem Soc 2010; 132:14733-5. [DOI: 10.1021/ja106167d] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- James S. Prell
- Department of Chemistry, University of California, Berkeley, California 94720-1460
| | - Thiago C. Correra
- Department of Chemistry, University of California, Berkeley, California 94720-1460
| | - Terrence M. Chang
- Department of Chemistry, University of California, Berkeley, California 94720-1460
| | - Jeffrey A. Biles
- Department of Chemistry, University of California, Berkeley, California 94720-1460
| | - Evan R. Williams
- Department of Chemistry, University of California, Berkeley, California 94720-1460
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