1
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Sun Z, Huang M, Liu C, Fang G, Chen N, Zhou D, Gao J. The formation of •OH with Fe-bearing smectite clays and low-molecular-weight thiols: Implication of As(III) removal. WATER RESEARCH 2020; 174:115631. [PMID: 32114017 DOI: 10.1016/j.watres.2020.115631] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 01/25/2020] [Accepted: 02/15/2020] [Indexed: 06/10/2023]
Abstract
Low-molecular-weight thiols (LMWTs) are widely occurring in waters and soils, which can act as electron shuttles in biogeochemical cycles. It is interesting to study the interactions between LMWTs and clay minerals, which would produce free radicals on clay surfaces and influence As(III) transformation. Batch experiments and spectroscopic analysis in combined with computational modeling were conducted with three Fe-bearing clay minerals (Na-NAu-1, Na-NAu-2 and Na-SAz-2) and four LMWTs (l-cysteine, cysteamine, homocysteine, and glutathione) to investigate the reaction mechanisms of LMWTs with Fe-bearing clay minerals and influences of clay types and LMWT structures on the interactions. The results showed that Fe-bearing clay minerals can improve 2.4-3.7 times of •OH formation in 96-h LMWTs oxidation. Quenching experiments confirmed surface-Fenton-like reactions were the main pathways of •OH formation in the presence of Fe-bearing smectite clay minerals. The most possible hypothesis is that structural Fe (III) can accept electrons from LMWTs through proton-coupled transfer from -SH functional group, which was supported by FTIR, XRD and Mössbauer spectroscopies. The results of DFT calculations suggested that clay surfaces could accelerate RS• formation and stabilize the radicals. The addition of Na-NAu-2 in the cystein solution could increase As(III) oxidation to As(V) from 16.3% to 42.0%. The results imply that in-situ •OH formation in the presence of LMWTs and smectite clays may be an important geochemical process for the transformation of environmental contaminants.
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Affiliation(s)
- Zhaoyue Sun
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science Chinese Academy of Sciences, Nanjing, 210008, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Meiying Huang
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science Chinese Academy of Sciences, Nanjing, 210008, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Cun Liu
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science Chinese Academy of Sciences, Nanjing, 210008, China
| | - Guodong Fang
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science Chinese Academy of Sciences, Nanjing, 210008, China
| | - Ning Chen
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu Province, 210023, China
| | - Dongmei Zhou
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science Chinese Academy of Sciences, Nanjing, 210008, China; State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu Province, 210023, China
| | - Juan Gao
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science Chinese Academy of Sciences, Nanjing, 210008, China.
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2
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Golec B, Nawara K, Thummel RP, Waluk J. Photoinduced oxidation of an indole derivative: 2-(1'H-indol-2'-yl)-[1,5]naphthyridine. Photochem Photobiol Sci 2019; 18:2225-2231. [PMID: 30896718 DOI: 10.1039/c8pp00587g] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The UV-induced oxidation of 2-(1'H-indol-2'-yl)-[1,5]naphthyridine acetonitrile solution in the presence of air leads to the formation of 2-(1,5-naphthyridin-2-yl)-4H-3,1-benzoxazin-4-one as a major product and N-(2-formylphenyl)-1,5-naphthyridine-2-carboxamide as a minor one. The probable reaction mechanisms are different for the two photoproducts and may involve both the reaction with singlet oxygen generated by the excited substrate or the reaction of the excited substrate with the ground state oxygen molecule. Electronic absorption and IR spectra indicate that both photoproducts are formed as mixtures of syn and anti-rotameric forms. The obtained results indicate an efficient and easy method for the synthesis of molecules with a benzoxazinone structure.
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Affiliation(s)
- Barbara Golec
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland.
| | - Krzysztof Nawara
- Faculty of Mathematics and Science, Cardinal Stefan Wyszyński University, Dewajtis 5, 01-815 Warsaw, Poland
| | - Randolph P Thummel
- Department of Chemistry, University of Houston, Houston, TX 77204-5003, USA
| | - Jacek Waluk
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland. and Faculty of Mathematics and Science, Cardinal Stefan Wyszyński University, Dewajtis 5, 01-815 Warsaw, Poland
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3
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Di Mascio P, Martinez GR, Miyamoto S, Ronsein GE, Medeiros MHG, Cadet J. Singlet Molecular Oxygen Reactions with Nucleic Acids, Lipids, and Proteins. Chem Rev 2019; 119:2043-2086. [DOI: 10.1021/acs.chemrev.8b00554] [Citation(s) in RCA: 253] [Impact Index Per Article: 50.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Paolo Di Mascio
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, CP 26077, CEP 05508-000, São Paulo, SP Brazil
| | - Glaucia R. Martinez
- Departamento de Bioquímica e Biologia Molecular, Setor de Ciências Biológicas, Universidade Federal do Paraná, 81531-990 Curitiba, PR, Brazil
| | - Sayuri Miyamoto
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, CP 26077, CEP 05508-000, São Paulo, SP Brazil
| | - Graziella E. Ronsein
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, CP 26077, CEP 05508-000, São Paulo, SP Brazil
| | - Marisa H. G. Medeiros
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, CP 26077, CEP 05508-000, São Paulo, SP Brazil
| | - Jean Cadet
- Département de Médecine Nucléaire et Radiobiologie, Faculté de Médecine des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, J1H 5N4 Québec, Canada
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4
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Hong Yang, Jia-Bao Li, Muhammad Kamran Siddiqui, Waqas Nazeer, Meysam Najafi. A Theoretical Examination of the Antioxidant Activity of NH2, OMe, and tert-Butyl Sesamol Derivatives and Their Drug Delivery with C60 Nanocage. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A 2018. [DOI: 10.1134/s0036024418130216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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5
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Marques EF, Medeiros MHG, Di Mascio P. Lysozyme oxidation by singlet molecular oxygen: Peptide characterization using [ 18 O]-labeling oxygen and nLC-MS/MS. JOURNAL OF MASS SPECTROMETRY : JMS 2017; 52:739-751. [PMID: 28801970 DOI: 10.1002/jms.3983] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Revised: 07/24/2017] [Accepted: 08/07/2017] [Indexed: 06/07/2023]
Abstract
Singlet molecular oxygen (1 O2 ) is generated in biological systems and reacts with different biomolecules. Proteins are a major target for 1 O2 , and His, Tyr, Met, Cys, and Trp are oxidized at physiological pH. In the present study, the modification of lysozyme protein by 1 O2 was investigated using mass spectrometry approaches. The experimental findings showed methionine, histidine, and tryptophan oxidation. The experiments were achieved using [18 O]-labeled 1 O2 released from thermolabile endoperoxides in association with nano-scale liquid chromatography coupled to electrospray ionization mass spectrometry. The structural characterization by nLC-MS/MS of the amino acids in the tryptic peptides of the proteins showed addition of [18 O]-labeling atoms in different amino acids.
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Affiliation(s)
- Emerson Finco Marques
- Departamento de Bioquímica and Departamento de Química Fundamental Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Marisa H G Medeiros
- Departamento de Bioquímica and Departamento de Química Fundamental Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Paolo Di Mascio
- Departamento de Bioquímica and Departamento de Química Fundamental Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
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6
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Lu W, Tsai IH“M, Sun Y, Zhou W, Liu J. Elucidating Potential Energy Surfaces for Singlet O2 Reactions with Protonated, Deprotonated, and Di-Deprotonated Cystine Using a Combination of Approximately Spin-Projected Density Functional Theory and Guided-Ion-Beam Mass Spectrometry. J Phys Chem B 2017; 121:7844-7854. [DOI: 10.1021/acs.jpcb.7b05674] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Wenchao Lu
- Department
of Chemistry and Biochemistry, Queens College of the City University of New York, 65-30 Kissena Blvd., Queens, New York 11367, United States
- Ph.D.
Program in Chemistry, The Graduate Center of the City University of New York, 365 5th Avenue, New York, New York 10016, United States
| | - I-Hsien “Midas” Tsai
- Department
of Natural Sciences, LaGuardia Community College, 31-10 Thomson Avenue, Long Island City, New York 11101, United States
| | - Yan Sun
- Department
of Chemistry and Biochemistry, Queens College of the City University of New York, 65-30 Kissena Blvd., Queens, New York 11367, United States
- Ph.D.
Program in Chemistry, The Graduate Center of the City University of New York, 365 5th Avenue, New York, New York 10016, United States
| | - Wenjing Zhou
- Department
of Chemistry and Biochemistry, Queens College of the City University of New York, 65-30 Kissena Blvd., Queens, New York 11367, United States
| | - Jianbo Liu
- Department
of Chemistry and Biochemistry, Queens College of the City University of New York, 65-30 Kissena Blvd., Queens, New York 11367, United States
- Ph.D.
Program in Chemistry, The Graduate Center of the City University of New York, 365 5th Avenue, New York, New York 10016, United States
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7
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Liu F, Lu W, Yin X, Liu J. Mechanistic and Kinetic Study of Singlet O2 Oxidation of Methionine by On-Line Electrospray Ionization Mass Spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2016; 27:59-72. [PMID: 26306590 DOI: 10.1007/s13361-015-1237-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Accepted: 07/24/2015] [Indexed: 06/04/2023]
Abstract
We report a reaction apparatus developed to monitor singlet oxygen ((1)O2) reactions in solution using on-line ESI mass spectrometry and spectroscopy measurements. (1)O2 was generated in the gas phase by the reaction of H2O2 with Cl2, detected by its emission at 1270 nm, and bubbled into aqueous solution continuously. (1)O2 concentrations in solution were linearly related to the emission intensities of airborne (1)O2, and their absolute scales were established based on a calibration using 9,10-anthracene dipropionate dianion as an (1)O2 trapping agent. Products from (1)O2 oxidation were monitored by UV-Vis absorption and positive/negative ESI mass spectra, and product structures were elucidated using collision-induced dissociation-tandem mass spectrometry. To suppress electrical discharge in negative ESI of aqueous solution, methanol was added to electrospray via in-spray solution mixing using theta-glass ESI emitters. Capitalizing on this apparatus, the reaction of (1)O2 with methionine was investigated. We have identified methionine oxidation intermediates and products at different pH, and measured reaction rate constants. (1)O2 oxidation of methionine is mediated by persulfoxide in both acidic and basic solutions. Persulfoxide continues to react with another methionine, yielding methionine sulfoxide as end-product albeit with a much lower reaction rate in basic solution. Density functional theory was used to explore reaction potential energy surfaces and establish kinetic models, with solvation effects simulated using the polarized continuum model. Combined with our previous study of gas-phase methionine ions with (1)O2, evolution of methionine oxidation pathways at different ionization states and in different media is described.
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Affiliation(s)
- Fangwei Liu
- Department of Chemistry and Biochemistry, Queens College and the Graduate Center of the City University of New York, Queens, NY, 11367, USA
| | - Wenchao Lu
- Department of Chemistry and Biochemistry, Queens College and the Graduate Center of the City University of New York, Queens, NY, 11367, USA
| | - Xunlong Yin
- Department of Chemistry and Biochemistry, Queens College and the Graduate Center of the City University of New York, Queens, NY, 11367, USA
| | - Jianbo Liu
- Department of Chemistry and Biochemistry, Queens College and the Graduate Center of the City University of New York, Queens, NY, 11367, USA.
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8
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Liu F, Liu J. Oxidation Dynamics of Methionine with Singlet Oxygen: Effects of Methionine Ionization and Microsolvation. J Phys Chem B 2015; 119:8001-12. [PMID: 26000762 DOI: 10.1021/acs.jpcb.5b03779] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We report an in-depth study on the gas-phase reactions of singlet O2[a(1)Δg] with methionine (Met) at different ionization and hydration states (including deprotonated [Met - H](-), hydrated deprotonated [Met - H](-)(H2O)1,2, and hydrated protonated MetH(+)(H2O)1,2), using guided-ion-beam scattering mass spectrometry. The measurements include the effects of collision energy (Ecol) on reaction cross sections over a center-of-mass Ecol range from 0.05 to 1.0 eV. The aim of this study is to probe the influences of Met ionization and hydration on its oxidation mechanism and dynamics. Density functional theory calculations, Rice-Ramsperger-Kassel-Marcus modeling, and quasi-classical, direct dynamics trajectory simulations were performed to examine the properties of various complexes and transition states that might be important along reaction coordinates, probe reaction potential energy surfaces, and to establish the atomic-level mechanism for the Met oxidation process. No oxidation products were observed for the reaction of [Met - H](-) with (1)O2 due to the high-energy barriers located in the product channels for this system. However, this nonreactive property was altered by the microsolvation of [Met - H](-); as a result, hydroperoxides were captured as the oxidation products for [Met - H](-)(H2O)1,2 + (1)O2. For the reaction of MetH(+)(H2O)1,2 + (1)O2, besides formation of hydroperoxides, an H2O2 elimination channel was observed. The latter channel is similar to what was found in the reaction of dehydrated MetH(+) with (1)O2 (J. Phys. Chem. B 2011, 115, 2671). The reactions of hydrated protonated and deprotonated Met are all inhibited by Ecol, becoming negligible at Ecol ≥ 0.5 eV. The kinetic and dynamical consequences of microsolvation on Met oxidation and their biological implications are discussed.
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Affiliation(s)
- Fangwei Liu
- Department of Chemistry and Biochemistry, Queens College and the Graduate Center of the City University of New York, Queens, New York 11367, United States
| | - Jianbo Liu
- Department of Chemistry and Biochemistry, Queens College and the Graduate Center of the City University of New York, Queens, New York 11367, United States
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9
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Liu F, Lu W, Fang Y, Liu J. Evolution of oxidation dynamics of histidine: non-reactivity in the gas phase, peroxides in hydrated clusters, and pH dependence in solution. Phys Chem Chem Phys 2014; 16:22179-91. [PMID: 25213401 DOI: 10.1039/c4cp03550j] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Oxidation of histidine by (1)O2 is an important process associated with oxidative damage to proteins during aging, diseases and photodynamic therapy of tumors and jaundice, and photochemical transformations of biological species in the troposphere. However, the oxidation mechanisms and products of histidine differ dramatically in these related environments which range from the gas phase through aerosols to aqueous solution. Herein we report a parallel gas- and solution-phase study on the (1)O2 oxidation of histidine, aimed at evaluating the evolution of histidine oxidation pathways in different media and at different ionization states. We first investigated the oxidation of protonated and deprotonated histidine ions and the same systems hydrated with explicit water molecules in the gas phase, using guided-ion-beam-scattering mass spectrometry. Reaction coordinates and potential energy surfaces for these systems were established on the basis of density functional theory calculations, Rice-Ramsperger-Kassel-Marcus modeling and direct dynamics simulations. Subsequently we tracked the oxidation process of histidine in aqueous solution under different pH conditions, using on-line UV-Vis spectroscopy and electrospray mass spectrometry monitoring systems. The results show that two different routes contribute to the oxidation of histidine depending on its ionization states. In each mechanism hydration is essential to suppressing the otherwise predominant dissociation of reaction intermediates back to reactants. The oxidation of deprotonated histidine in the gas phase involves the formation of 2,4-endoperoxide and 2-hydroperoxide of imidazole. These intermediates evolve to hydrated imidazolone in solution, and the latter either undergoes ring-closure to 6α-hydoxy-2-oxo-octahydro-pyrrolo[2,3-d]imidazole-5-carboxylate or cross-links with another histidine to form a dimeric product. In contrast, the oxidation of protonated histidine is mediated by 2,5-endoperoxide and 5-hydroperoxide, which convert to stable hydrated imidazolone end-product in solution. The contrasting mechanisms and reaction efficiencies of protonated vs. deprotonated histidine, which lead to pH dependence in the photooxidation of histidine, are interpreted in terms of the chemistry of imidazole with (1)O2. The biological implications of the results are also discussed.
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Affiliation(s)
- Fangwei Liu
- Department of Chemistry and Biochemistry, Queens College and the Graduate Center of the City University of New York, 65-30 Kissena Blvd., Queens, New York 11367, USA.
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10
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Lu W, Liu F, Emre R, Liu J. Collision dynamics of protonated N-acetylmethionine with singlet molecular oxygen (a(1)Δg): the influence of the amide bond and ruling out the complex-mediated mechanism at low energies. J Phys Chem B 2014; 118:3844-52. [PMID: 24646013 DOI: 10.1021/jp500780m] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
It has been proposed (J. Phys. Chem. B 2011, 115, 2671) that the ammonium group is involved in the gas-phase reaction of protonated methionine (MetH(+)) with singlet oxygen (1)O2, yielding hydrogen peroxide and a dehydro compound of MetH(+) where the -NH3(+) transforms into cyclic -NH2-. For the work reported, the gas-phase reaction of protonated N-acetylmethionine (Ac-MetH(+)) with (1)O2 was examined, including the measurements of reaction products and cross sections over a center-of-mass collision energy (Ecol) range from 0.05 to 1.0 eV using a guided-ion-beam apparatus. The aim is to probe how the acetylation of the ammonium group affects the oxidation chemistry of the ensuing Ac-MetH(+). Properties of intermediates, transition states, and products along the reaction coordinate were explored using density functional theory calculations and Rice-Ramsperger-Kassel-Marcus (RRKM) modeling. Direct dynamics trajectory simulations were carried out at Ecol of 0.05 and 0.1 eV using the B3LYP/4-31G(d) level of theory. In contrast to the highly efficient reaction of MetH(+) + (1)O2, the reaction of Ac-MetH(+) + (1)O2 is extremely inefficient, despite there being exoergic pathways. Two product channels were observed, corresponding to transfer of two H atoms from Ac-MetH(+) to (1)O2 (H2T), and methyl elimination (ME) from a sulfone intermediate complex. Both channels are inhibited by collision energies, becoming negligible at Ecol > 0.2 eV. Analysis of RRKM and trajectory results suggests that a complex-mediated mechanism might be involved at very low Ecol, but direct, nonreactive collisions prevail over the entire Ecol range and physical quenching of (1)O2 occurs during the early stage of collisions.
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Affiliation(s)
- Wenchao Lu
- Department of Chemistry and Biochemistry, Queens College and the Graduate Center of the City University of New York , 65-30 Kissena Boulevard, Queens, New York 11367, United States
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11
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Farmanzadeh D, Najafi M. On the Antioxidant Activity of the Tryptophan Derivatives. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2013. [DOI: 10.1246/bcsj.20130035] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Davood Farmanzadeh
- Department of Physical Chemistry, Faculty of Chemistry, University of Mazandaran
| | - Meysam Najafi
- Department of Physical Chemistry, Faculty of Chemistry, University of Mazandaran
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12
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Fang Y, Liu F, Emre R, Liu J. Guided-Ion-Beam Scattering and Direct Dynamics Trajectory Study on the Reaction of Deprotonated Cysteine with Singlet Molecular Oxygen. J Phys Chem B 2013; 117:2878-87. [DOI: 10.1021/jp4002077] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Yigang Fang
- Department of Chemistry and Biochemistry, Queens College and the Graduate Center of the City University of New York, 65-30 Kissena Boulevard, Queens, New York
11367, United States
| | - Fangwei Liu
- Department of Chemistry and Biochemistry, Queens College and the Graduate Center of the City University of New York, 65-30 Kissena Boulevard, Queens, New York
11367, United States
| | - Rifat Emre
- Department of Chemistry and Biochemistry, Queens College and the Graduate Center of the City University of New York, 65-30 Kissena Boulevard, Queens, New York
11367, United States
| | - Jianbo Liu
- Department of Chemistry and Biochemistry, Queens College and the Graduate Center of the City University of New York, 65-30 Kissena Boulevard, Queens, New York
11367, United States
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13
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Fang Y, Liu F, Liu J. Mass spectrometry study of multiply negatively charged, gas-phase NaAOT micelles: how does charge state affect micellar structure and encapsulation? JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2013; 24:9-20. [PMID: 23247969 DOI: 10.1007/s13361-012-0530-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2012] [Revised: 10/26/2012] [Accepted: 10/30/2012] [Indexed: 06/01/2023]
Abstract
We report the formation and characterization of multiply negatively charged sodium bis(2-ethylhexyl) sulfosuccinate (NaAOT) aggregates in the gas phase, by electrospray ionization of methanol/water solution of NaAOT followed by detection using a guided-ion-beam tandem mass spectrometer. Singly and doubly charged aggregates dominate the mass spectra with the compositions of [Na(n-z)AOT(n)](z-) (n = 1-18 and z = 1-2). Solvation by water was detected only for small aggregates [Na(n-1)AOT(n)H(2)O](-) of n = 3-9. Incorporation of glycine and tryptophan into [Na(n-z)AOT(n)](z-) aggregates was achieved, aimed at identifying effects of guest molecule hydrophobicity on micellar solubilization. Only one glycine molecule could be incorporated into each [Na(n-z)AOT(n)](z-) of n ≥ 7, and at most two glycine molecules could be hosted in that of n ≥ 13. In contrast to glycine, up to four tryptophan molecules could be accommodated within single aggregates of n ≥ 6. However, deprotonation of tryptophan significantly decrease its affinity towards aggregates. Collision-induced dissociation (CID) was carried out for mass-selected aggregate ions, including measurements of product ion mass spectra for both empty and amino acid-containing aggregates. CID results provide a probe for aggregate structures, surfactant-solute interactions, and incorporation sites of amino acids. The present data was compared with mass spectrometry results of positively charged [Na(n+z)AOT(n)](z+) aggregates. Contrary to their positive analogues, which form reverse micelles, negatively charged aggregates may adopt a direct micelle-like structure with AOT polar heads exposed and amino acids being adsorbed near the micellar outer surface.
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Affiliation(s)
- Yigang Fang
- Department of Chemistry and Biochemistry, Queens College and the Graduate Center of the City University of New York, 65-30 Kissena Blvd, Flushing, NY 11367, USA
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14
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Liu F, Emre R, Lu W, Liu J. Oxidation of gas-phase hydrated protonated/deprotonated cysteine: how many water ligands are sufficient to approach solution-phase photooxidation chemistry? Phys Chem Chem Phys 2013; 15:20496-509. [DOI: 10.1039/c3cp53736f] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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15
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Liu F, Fang Y, Chen Y, Liu J. Reactions of Deprotonated Tyrosine and Tryptophan with Electronically Excited Singlet Molecular Oxygen (a1Δg): A Guided-Ion-Beam Scattering, Statistical Modeling, and Trajectory Study. J Phys Chem B 2012; 116:6369-79. [DOI: 10.1021/jp303022b] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- Fangwei Liu
- Department of Chemistry
and Biochemistry, Queens College and the Graduate Center of the City University of New York,
65-30 Kissena Blvd., Flushing, New York 11367, United States
| | - Yigang Fang
- Department of Chemistry
and Biochemistry, Queens College and the Graduate Center of the City University of New York,
65-30 Kissena Blvd., Flushing, New York 11367, United States
| | - Yun Chen
- Department of Chemistry
and Biochemistry, Queens College and the Graduate Center of the City University of New York,
65-30 Kissena Blvd., Flushing, New York 11367, United States
| | - Jianbo Liu
- Department of Chemistry
and Biochemistry, Queens College and the Graduate Center of the City University of New York,
65-30 Kissena Blvd., Flushing, New York 11367, United States
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16
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Bartusik D, Aebisher D, Ghafari B, Lyons AM, Greer A. Generating singlet oxygen bubbles: a new mechanism for gas-liquid oxidations in water. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:3053-60. [PMID: 22260325 PMCID: PMC3329934 DOI: 10.1021/la204583v] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Laser-coupled microphotoreactors were developed to bubble singlet oxygen [(1)O(2) ((1)Δ(g))] into an aqueous solution containing an oxidizable compound. The reactors consisted of custom-modified SMA fiberoptic receptacles loaded with 150 μm silicon phthalocyanine glass sensitizer particles, where the particles were isolated from direct contact with water by a membrane adhesively bonded to the bottom of each device. A tube fed O(2) gas to the reactor chambers. In the presence of O(2), singlet oxygen was generated by illuminating the sensitizer particles with 669 nm light from an optical fiber coupled to the top of the reactor. The generated (1)O(2) was transported through the membrane by the O(2) stream and formed bubbles in solution. In solution, singlet oxygen reacted with probe compounds (9,10-anthracene dipropionate dianion, trans-2-methyl-2-pentanoate anion, N-benzoyl-D,L-methionine, or N-acetyl-D,L-methionine) to give oxidized products in two stages. The early stage was rapid and showed that (1)O(2) transfer occurred via bubbles mainly in the bulk water solution. The later stage was slow; it arose only from (1)O(2)-probe molecule contact at the gas/liquid interface. A mechanism is proposed that involves (1)O(2) mass transfer and solvation, where smaller bubbles provide better penetration of (1)O(2) into the flowing stream due to higher surface-to-volume contact between the probe molecules and (1)O(2).
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Affiliation(s)
- Dorota Bartusik
- Department of Chemistry, Brooklyn College, City University of New York, Brooklyn, New York 11210
| | - David Aebisher
- Department of Chemistry, Brooklyn College, City University of New York, Brooklyn, New York 11210
| | - BiBi Ghafari
- Department of Chemistry, College of Staten Island, City University of New York, Staten Island, New York 10314
| | - Alan M. Lyons
- Department of Chemistry, College of Staten Island, City University of New York, Staten Island, New York 10314
| | - Alexander Greer
- Department of Chemistry, Brooklyn College, City University of New York, Brooklyn, New York 11210
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