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Wang D, Koh E, Lee KA, Chung HS. Chemical constituents from
Betula schmidtii
and their free radical scavenging, tyrosinase inhibitory, and neuroprotective activities. B KOREAN CHEM SOC 2022. [DOI: 10.1002/bkcs.12650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Affiliation(s)
- Da‐Hye Wang
- College of Science and Technology Duksung Women's University Seoul Republic of Korea
| | - Eun‐Hie Koh
- College of Science and Technology Duksung Women's University Seoul Republic of Korea
| | - Kyung Ae Lee
- Department of Food and Nutrition Anyang University Anyang Republic of Korea
| | - Ha Sook Chung
- College of Science and Technology Duksung Women's University Seoul Republic of Korea
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2
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Santos MA, Irto A, Buglyó P, Chaves S. Hydroxypyridinone-Based Metal Chelators towards Ecotoxicity: Remediation and Biological Mechanisms. Molecules 2022; 27:1966. [PMID: 35335329 PMCID: PMC8950932 DOI: 10.3390/molecules27061966] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 03/13/2022] [Accepted: 03/14/2022] [Indexed: 01/29/2023] Open
Abstract
Hydroxypyridinones (HPs) are recognized as excellent chemical tools for engineering a diversity of metal chelating agents, with high affinity for hard metal ions, exhibiting a broad range of activities and applications, namely in medical, biological and environmental contexts. They are easily made and functionalizable towards the tuning of their pharmacokinetic properties or the improving of their metal complex thermodynamic stabilities. In this review, an analysis of the recently published works on hydroxypyridinone-based ligands, that have been mostly addressed for environmental applications, namely for remediation of hard metal ion ecotoxicity in living beings and other biological matrices is carried out. In particular, herein the most recent developments in the design of new chelating systems, from bidentate mono-HP to polydentate multi-HP derivatives, with a structural diversity of soluble or solid-supported backbones are outlined. Along with the ligand design, an analysis of the relationship between their structures and activities is presented and discussed, namely associated with the metal affinity and the thermodynamic stability of the corresponding metal complexes.
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Affiliation(s)
- M. Amélia Santos
- Centro de Química Estrutural and Departamento de Engenharia Química, Institute of Molecular Sciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais 1, 1049-001 Lisboa, Portugal
| | - Anna Irto
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, Università di Messina, Viale F. Stagno d’Alcontres, 31, I-98166 Messina, Italy;
| | - Péter Buglyó
- Department of Inorganic and Analytical Chemistry, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary;
| | - Sílvia Chaves
- Centro de Química Estrutural and Departamento de Engenharia Química, Institute of Molecular Sciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais 1, 1049-001 Lisboa, Portugal
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3
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Besalú-Sala P, Magallón C, Costas M, Company A, Luis JM. Mechanistic Insights into the ortho-Defluorination-Hydroxylation of 2-Halophenolates Promoted by a Bis(μ-oxo)dicopper(III) Complex. Inorg Chem 2020; 59:17018-17027. [PMID: 33156988 DOI: 10.1021/acs.inorgchem.0c02246] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
C-F bonds are one of the most inert functionalities. Nevertheless, some [Cu2O2]2+ species are able to defluorinate-hydroxylate ortho-fluorophenolates in a chemoselective manner over other ortho-halophenolates. Albeit it is known that such reactivity is promoted by an electrophilic attack of a [Cu2O2]2+ core over the arene ring, the crucial details of the mechanism that explain the chemo- and regioselectivity of the reaction remain unknown, and it has not being determined either if CuII2(η2:η2-O2) or CuIII2(μ-O)2 species are responsible for the initial attack on the arene. Herein, we present a combined theoretical and experimental mechanistic study to unravel the origin of the chemoselectivity of the ortho-defluorination-hydroxylation of 2-halophenolates by the [Cu2(O)2(DBED)2]2+ complex (DBED = N,N'-di-tert-butylethylenediamine). Our results show that the equilibria between (side-on)peroxo (P) and bis(μ-oxo) (O) isomers plays a key role in the mechanism, with the latter being the reactive species. Furthermore, on the basis of quantum-mechanical calculations, we were able to rationalize the chemoselective preference of the [Cu2(O)2(DBED)2]2+ catalyst for the C-F activation over C-Cl and C-H activations.
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Affiliation(s)
- Pau Besalú-Sala
- Institut de Química Computacional i Catàlisi and Departament de Química, Universitat de Girona, C/Maria Aurèlia Capmany 69, 17003 Girona, Catalonia, Spain
| | - Carla Magallón
- Institut de Química Computacional i Catàlisi and Departament de Química, Universitat de Girona, C/Maria Aurèlia Capmany 69, 17003 Girona, Catalonia, Spain
| | - Miquel Costas
- Institut de Química Computacional i Catàlisi and Departament de Química, Universitat de Girona, C/Maria Aurèlia Capmany 69, 17003 Girona, Catalonia, Spain
| | - Anna Company
- Institut de Química Computacional i Catàlisi and Departament de Química, Universitat de Girona, C/Maria Aurèlia Capmany 69, 17003 Girona, Catalonia, Spain
| | - Josep M Luis
- Institut de Química Computacional i Catàlisi and Departament de Química, Universitat de Girona, C/Maria Aurèlia Capmany 69, 17003 Girona, Catalonia, Spain
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4
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Abe T, Shiota Y, Itoh S, Yoshizawa K. Theoretical rationalization for the equilibrium between (μ-η 2:η 2-peroxido)Cu IICu II and bis(μ-oxido)Cu IIICu III complexes: perturbational effects from ligand frameworks. Dalton Trans 2020; 49:6710-6717. [PMID: 32368776 DOI: 10.1039/d0dt01001d] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
DFT calculations are carried out to investigate the geometric effects of the supporting ligands in the relative energies of the (μ-η2:η2-peroxido)CuIICuII complex 1 and the bis(μ-oxido)CuIIICuIII complex 2. The N3-tridentate ligand bearing acyclic propane diamine framework La preferentially provided 1, whereas the N3-tridentate ligand with cyclic diamine framework such as 1,4-diazacycloheptane Lb gave 2 after the oxygenation of the corresponding CuI complexes as reported previously [S. Itoh, et al., Inorg. Chem., 2014, 53, 8786-8794]. Calculations at the B3LYP*-D3 level of theory can reasonably explain the experimental results in relative energies, structures and harmonic frequencies of 1 and 2. Perturbational effects of the diamine chelates of La and Lb especially on the equilibrium of 1 and 2 are investigated in detail. In the range from 2.30 Å to 3.40 Å of the N-N distance in the diamine moiety, 1 is more stable than 2 by 8.4 kcal mol-1 at the distance of 3.40 Å. Calculated potential energies indicate that the decrease in the N-N distance is associated with a decrease in energy of 2, leading that 2 can be most stabilized at the N-N distance of 2.60 Å. Furthermore, molecular orbitals analyses are performed to explain that the energy gaps between the σ* orbital of the O-O bond and the dx2-y2 orbitals of the CuII ions of 1 get small as the diamine moiety is shrunk, leading to facilitate the O-O bond cleavage from 1 to 2.
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Affiliation(s)
- Tsukasa Abe
- Institute for Materials Chemistry and Engineering and IRCCS, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, Japan.
| | - Yoshihito Shiota
- Institute for Materials Chemistry and Engineering and IRCCS, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, Japan.
| | - Shinobu Itoh
- Department of Material and Life Science, Division of Advanced Science and Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka, Japan
| | - Kazunari Yoshizawa
- Institute for Materials Chemistry and Engineering and IRCCS, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, Japan.
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5
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Lan W, Wang X, He L, Meng Y, Li J, Qiu B, Nie C. Computational insight into asymmetric uranyl‐salophen coordinated with α, β‐unsaturated aldehydes and ketones. Appl Organomet Chem 2017. [DOI: 10.1002/aoc.4137] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Wen‐Bo Lan
- School of Public HealthXiangnan University Chenzhou Hunan 423000 China
- School of Chemistry and Chemical EngineeringUniversity of South China Hengyang China
| | - Xiao‐Feng Wang
- School of Public HealthXiangnan University Chenzhou Hunan 423000 China
| | - Li‐Ping He
- School of Public HealthXiangnan University Chenzhou Hunan 423000 China
| | - Yan‐Bin Meng
- School of Public HealthXiangnan University Chenzhou Hunan 423000 China
| | - Jun Li
- School of Public HealthXiangnan University Chenzhou Hunan 423000 China
| | - Bin Qiu
- Chenzhou City Center for Disease Control and Prevention Chenzhou Hunan 423000 China
| | - Chang‐Ming Nie
- School of Chemistry and Chemical EngineeringUniversity of South China Hengyang China
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6
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Chen K, Zhao DY, Chen YL, Wei XY, Li YT, Kong LM, Hider RC, Zhou T. A Novel Inhibitor Against Mushroom Tyrosinase with a Double Action Mode and Its Application in Controlling the Browning of Potato. FOOD BIOPROCESS TECH 2017. [DOI: 10.1007/s11947-017-1976-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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7
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Rohrmüller M, Hoffmann A, Thierfelder C, Herres-Pawlis S, Schmidt WG. The Cu2O2torture track for a real-life system: [Cu2(btmgp)2O2]2+oxo and peroxo species in density functional calculations†. J Comput Chem 2015; 36:1672-85. [DOI: 10.1002/jcc.23983] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Revised: 05/26/2015] [Accepted: 05/28/2015] [Indexed: 01/23/2023]
Affiliation(s)
- Martin Rohrmüller
- Universität Paderborn, Department Physik, Lehrstuhl für Theoretische Physik; Pohlweg 55 33095 Paderborn Germany
| | - Alexander Hoffmann
- RWTH Aachen University, Fachgruppe Chemie, Lehrstuhl für Bioanorganische Chemie; Landoltweg 1 52074 Aachen Germany
| | - Christian Thierfelder
- Universität Paderborn, Department Physik, Lehrstuhl für Theoretische Physik; Pohlweg 55 33095 Paderborn Germany
| | - Sonja Herres-Pawlis
- RWTH Aachen University, Fachgruppe Chemie, Lehrstuhl für Bioanorganische Chemie; Landoltweg 1 52074 Aachen Germany
| | - Wolf Gero Schmidt
- Universität Paderborn, Department Physik, Lehrstuhl für Theoretische Physik; Pohlweg 55 33095 Paderborn Germany
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8
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Winikoff SG, Cramer CJ. Mechanistic analysis of water oxidation catalyzed by mononuclear copper in aqueous bicarbonate solutions. Catal Sci Technol 2014. [DOI: 10.1039/c4cy00500g] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
We characterize a mechanism for a monomeric copper catalyst reported to oxidize water in bicarbonate solution when subject to sufficiently high external potentials at near neutral pH values.
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Affiliation(s)
- Stuart G. Winikoff
- Department of Chemistry
- Chemical Theory Center, and Supercomputing Institute
- Minneapolis, USA
| | - Christopher J. Cramer
- Department of Chemistry
- Chemical Theory Center, and Supercomputing Institute
- Minneapolis, USA
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9
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Amin M, Vogt L, Vassiliev S, Rivalta I, Sultan MM, Bruce D, Brudvig GW, Batista VS, Gunner MR. Electrostatic effects on proton coupled electron transfer in oxomanganese complexes inspired by the oxygen-evolving complex of photosystem II. J Phys Chem B 2013; 117:6217-26. [PMID: 23570540 DOI: 10.1021/jp403321b] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The influence of electrostatic interactions on the free energy of proton coupled electron transfer in biomimetic oxomanganese complexes inspired by the oxygen-evolving complex (OEC) of photosystem II (PSII) are investigated. The reported study introduces an enhanced multiconformer continuum electrostatics (MCCE) model, parametrized at the density functional theory (DFT) level with a classical valence model for the oxomanganese core. The calculated pKa's and oxidation midpoint potentials (E(m)'s) match experimental values for eight complexes, indicating that purely electrostatic contributions account for most of the observed couplings between deprotonation and oxidation state transitions. We focus on pKa's of terminal water ligands in [Mn(II/III)(H2O)6](2+/3+) (1), [Mn(III)(P)(H2O)2](3-) (2, P = 5,10,15,20-tetrakis(2,6-dichloro-3-sulfonatophenyl)porphyrinato), [Mn2(IV,IV)(μ-O)2(terpy)2(H2O)2](4+) (3, terpy = 2,2':6',2″-terpyridine), and [Mn3(IV,IV,IV)(μ-O)4(phen)4(H2O)2](4+) (4, phen = 1,10-phenanthroline) and the pKa's of μ-oxo bridges and Mn E(m)'s in [Mn2(μ-O)2(bpy)4] (5, bpy = 2,2'-bipyridyl), [Mn2(μ-O)2(salpn)2] (6, salpn = N,N'-bis(salicylidene)-1,3-propanediamine), [Mn2(μ-O)2(3,5-di(Cl)-salpn)2] (7), and [Mn2(μ-O)2(3,5-di(NO2)-salpn)2] (8). The analysis of complexes 6-8 highlights the strong coupling between electron and proton transfers, with any Mn oxidation lowering the pKa of an oxo bridge by 10.5 ± 0.9 pH units. The model also accounts for changes in the E(m)'s by ligand substituents, such as found in complexes 6-8, due to the electron withdrawing Cl (7) and NO2 (8). The reported study provides the foundation for analysis of electrostatic effects in other oxomanganese complexes and metalloenzymes, where proton coupled electron transfer plays a fundamental role in redox-leveling mechanisms.
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Affiliation(s)
- Muhamed Amin
- Department of Physics, City College of New York, New York, New York 10031, United States
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10
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Poater A, Solà M. Complete σ* intramolecular aromatic hydroxylation mechanism through O2 activation by a Schiff base macrocyclic dicopper(I) complex. Beilstein J Org Chem 2013; 9:585-93. [PMID: 23616799 PMCID: PMC3628990 DOI: 10.3762/bjoc.9.63] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2012] [Accepted: 03/01/2013] [Indexed: 02/05/2023] Open
Abstract
In this work we analyze the whole molecular mechanism for intramolecular aromatic hydroxylation through O2 activation by a Schiff hexaazamacrocyclic dicopper(I) complex, [Cu(I) 2(bsH2m)](2+). Assisted by DFT calculations, we unravel the reaction pathway for the overall intramolecular aromatic hydroxylation, i.e., from the initial O2 reaction with the dicopper(I) species to first form a Cu(I)Cu(II)-superoxo species, the subsequent reaction with the second Cu(I) center to form a μ-η(2):η(2)-peroxo-Cu(II) 2 intermediate, the concerted peroxide O-O bond cleavage and C-O bond formation, followed finally by a proton transfer to an alpha aromatic carbon that immediately yields the product [Cu(II) 2(bsH2m-O)(μ-OH)](2+).
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Affiliation(s)
- Albert Poater
- Institut de Química Computacional i Catàlisi and Departament de Química, Universitat de Girona, Campus de Montilivi, E-17071 Girona, Spain ; Catalan Institute for Water Research (ICRA), H2O Building, Scientific and Technological Park of the University of Girona, Emili Grahit 101, E-17003 Girona, Spain
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11
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12
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Dancing multiplicity states supported by a carboxylated group in dicopper structures bonded to O2. Theor Chem Acc 2013. [DOI: 10.1007/s00214-013-1336-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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13
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Rohrmüller M, Herres-Pawlis S, Witte M, Schmidt WG. Bis-μ-oxo and μ-η2:η2-peroxo dicopper complexes studied within (time-dependent) density-functional and many-body perturbation theory. J Comput Chem 2013; 34:1035-45. [DOI: 10.1002/jcc.23230] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Revised: 12/13/2012] [Accepted: 12/14/2012] [Indexed: 02/03/2023]
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14
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Comba P, Martin B, Muruganantham A, Straub J. Structure, Bonding, and Catecholase Mechanism of Copper Bispidine Complexes. Inorg Chem 2012; 51:9214-25. [DOI: 10.1021/ic3004917] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Peter Comba
- Universität Heidelberg, Anorganisch-Chemisches
Institut, INF 270, D-69120 Heidelberg, Germany
| | - Bodo Martin
- Universität Heidelberg, Anorganisch-Chemisches
Institut, INF 270, D-69120 Heidelberg, Germany
| | - Amsaveni Muruganantham
- Universität Heidelberg, Anorganisch-Chemisches
Institut, INF 270, D-69120 Heidelberg, Germany
| | - Johannes Straub
- Universität Heidelberg, Anorganisch-Chemisches
Institut, INF 270, D-69120 Heidelberg, Germany
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15
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Comba P, Haaf C, Helmle S, Karlin KD, Pandian S, Waleska A. Dioxygen reactivity of new bispidine-copper complexes. Inorg Chem 2012; 51:2841-51. [PMID: 22332786 DOI: 10.1021/ic2019296] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The reactivity of copper complexes of three different second-generation bispidine-based ligands (bispidine = 3,7-diazabicyclo[3.3.1]nonane; mono- and bis-tetradentate; exclusively tertiary amine donors) with dioxygen [(reversible) binding of dioxygen by copper(I)] is reported. The UV-vis, electrospray ionization mass spectrometry, electron paramagnetic resonance, and vibrational spectra (resonance Raman) of the dioxygen adducts indicate that, depending on the ligand and reaction conditions, several different species (mono- and dinuclear, superoxo, peroxo, and hydroperoxo), partially in equilibrium with each other, are formed. Minor changes in the ligand structure and/or experimental conditions (solvent, temperature, relative concentrations) allow switching between the different forms. With one of the ligands, an end-on peroxodicopper(II) complex and a mononuclear hydroperoxocopper(II) complex could be characterized. With another ligand, reversible dioxygen binding was observed, leading to a metastable superoxocopper(II) complex. The amount of dioxygen involved in the reversible binding to Cu(I) was determined quantitatively. The mechanism of dioxygen binding as well as the preference of each of the three ligands for a particular dioxygen adduct is discussed on the basis of a computational (density functional theory) analysis.
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Affiliation(s)
- Peter Comba
- Anorganisch-Chemisches Institut, Universität Heidelberg, INF 270, D-69120 Heidelberg, Germany.
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16
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Correlated wavefunction methods in bioinorganic chemistry. J Biol Inorg Chem 2011; 16:821-9. [PMID: 21541855 DOI: 10.1007/s00775-011-0787-6] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2011] [Accepted: 04/20/2011] [Indexed: 10/18/2022]
Abstract
In this commentary the challenges faced in the application of wavefunction-based ab initio methods to (open-shell) transition metal complexes of (bio)inorganic interest are briefly touched on. Both single-reference and multireference methods are covered. It is stressed that the generation and nature of the reference wavefunction is a subject of major importance. How erroneous results can be easily obtained even with coupled-cluster theory is illustrated through the example of the septet-quintet separation in iron(IV)-oxo complexes. Second, the interplay between relativistic and correlation effects is important. This is demonstrated with coupled-cluster calculations on models for dinuclear copper active sites, where relativity has a major influence on the relative stabilities of the bis(μ-oxo) and side-on peroxo species.
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17
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Liakos DG, Neese F. Interplay of Correlation and Relativistic Effects in Correlated Calculations on Transition-Metal Complexes: The (Cu2O2)2+ Core Revisited. J Chem Theory Comput 2011; 7:1511-23. [DOI: 10.1021/ct1006949] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Dimitrios G. Liakos
- Lehrstuhl für Theoretische Chemie, Universität Bonn, Wegelerstrasse 12, D-53115 Bonn, Germany
| | - Frank Neese
- Lehrstuhl für Theoretische Chemie, Universität Bonn, Wegelerstrasse 12, D-53115 Bonn, Germany
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18
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Cheng L, Wang J, Wang M, Wu Z. Mechanistic insight into the alcohol oxidation mediated by an efficient green [CuBr(2)(2,2'-bipy)]-TEMPO catalyst by density functional method. Inorg Chem 2011; 49:9392-9. [PMID: 20849129 DOI: 10.1021/ic100996b] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Density functional theory (DFT) calculations have been performed to investigate the alcohol oxidation to acetaldehyde catalyzed by [CuBr(2)(2,2'-bipy)]-TEMPO (TEMPO stands for 2,2,6,6-tetramethylpiperidinyloxy; bipy stands for bipyridine). The total charge for the studied catalytic system is +1. The catalytic cycle consists of two parts, namely, alcohol oxidation and TEMPO regeneration. In alcohol oxidation, the reaction follows the Sheldon's mechanism for the proposed two mechanisms, i.e., Semmelhack's mechanism and Sheldon's mechanism. The water participation plays minor role in the H atom abstraction step. In TEMPO regeneration, the proposed three paths are competitive in energy. By comparing with experimental observation, it is found that the path, in which alcohol provides the proton to TEMPO(-) to produce TEMPOH followed by the oxidation of TEMPOH directly to TEMPO by O(2), is favored. In TEMPO regeneration, CH(3)CN acts as the ligand to stabilize the Cu(I) species during the catalytic cycle.
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Affiliation(s)
- Lin Cheng
- State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, PR China
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19
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Cheng L, Wang J, Wang M, Wu Z. Mechanistic insight into alcohol oxidation mediated by an efficient green CuII-bipy catalyst with and without TEMPO by density functional methods. Dalton Trans 2010; 39:5377-87. [DOI: 10.1039/b926098f] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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20
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Poater A. Oxidation of Copper(I) Hexaaza Macrocyclic Dinuclear Complexes. J Phys Chem A 2009; 113:9030-40. [DOI: 10.1021/jp9040716] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Albert Poater
- Modeling Lab for Nanostructures and Catalysis (MoLNaC), Dipartimento di Chimica, Università degli Studi di Salerno, via Ponte don Melillo, Fisciano (SA) 84084, Italy
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21
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Poater A, Cavallo L. Probing the mechanism of O2 activation by a copper(I) biomimetic complex of a C-H hydroxylating copper monooxygenase. Inorg Chem 2009; 48:4062-6. [PMID: 19331376 DOI: 10.1021/ic802269v] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
In this paper, we report, for the first time, a plausible full reaction pathway for the activation of O(2) by a tetraazamacrocyclic monocopper(I) complex and for the subsequent intramolecular alkylic hydroxylation to yield the alkoxide product. This theoretical insight offers remarkable support to the fundamental hypothesis in the field that a hydroperoxo complex of the type Cu(II)OOH intermediate is the key intermediate in this class of reactions. Overall, we give insight into an intramolecular alkylic C-H bond activation due to the O(2) binding to copper(I) with an end-on eta(1)-O(2) ligation. The loss of a water molecule involves the final substrate oxygenation. The complex we consider is a biomimetic of several systems of biological relevance, such as amine oxidases, peptidylglycine-alpha-hydroxylating monooxygenase, and dopamine-beta monooxygenases.
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Affiliation(s)
- Albert Poater
- Dipartimento di Chimica, Università degli Studi di Salerno, via Ponte don Melillo, Fisciano (SA) 84084, Italy.
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22
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Güell M, Luis JM, Solà M, Siegbahn PEM. Theoretical study of the hydroxylation of phenolates by the Cu(2)O (2)(N,N'-dimethylethylenediamine) (2) (2+) complex. J Biol Inorg Chem 2008; 14:229-42. [PMID: 18972140 DOI: 10.1007/s00775-008-0443-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2008] [Accepted: 10/08/2008] [Indexed: 12/21/2022]
Abstract
Tyrosinase catalyzes the ortho hydroxylation of monophenols and the subsequent oxidation of the diphenolic products to the resulting quinones. In efforts to create biomimetic copper complexes that can oxidize C-H bonds, Stack and coworkers recently reported a synthetic mu-eta(2):eta(2)-peroxodicopper(II)(DBED)(2) complex (DBED is N,N'-di-tert-butylethylenediamine), which rapidly hydroxylates phenolates. A reactive intermediate consistent with a bis-mu-oxo-dicopper(III)-phenolate complex, with the O-O bond fully cleaved, is observed experimentally. Overall, the evidence for sequential O-O bond cleavage and C-O bond formation in this synthetic complex suggests an alternative mechanism to the concerted or late-stage O-O bond scission generally accepted for the phenol hydroxylation reaction performed by tyrosinase. In this work, the reaction mechanism of this peroxodicopper(II) complex was studied with hybrid density functional methods by replacing DBED in the mu-eta(2):eta(2)-peroxodicopper(II)(DBED)(2) complex by N,N'-dimethylethylenediamine ligands to reduce the computational costs. The reaction mechanism obtained is compared with the existing proposals for the catalytic ortho hydroxylation of monophenol and the subsequent oxidation of the diphenolic product to the resulting quinone with the aim of gaining some understanding about the copper-promoted oxidation processes mediated by 2:1 Cu(I)O(2)-derived species.
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Affiliation(s)
- Mireia Güell
- Departament de Química, Institut de Química Computacional, Universitat de Girona, Campus de Montilivi, 17071, Girona, Spain
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Malmqvist PA, Pierloot K, Shahi ARM, Cramer CJ, Gagliardi L. The restricted active space followed by second-order perturbation theory method: theory and application to the study of CuO2 and Cu2O2 systems. J Chem Phys 2008; 128:204109. [PMID: 18513012 DOI: 10.1063/1.2920188] [Citation(s) in RCA: 367] [Impact Index Per Article: 22.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A multireference second-order perturbation theory using a restricted active space self-consistent field wave function as reference (RASPT2/RASSCF) is described. This model is particularly effective for cases where a chemical system requires a balanced orbital active space that is too large to be addressed by the complete active space self-consistent field model with or without second-order perturbation theory (CASPT2 or CASSCF, respectively). Rather than permitting all possible electronic configurations of the electrons in the active space to appear in the reference wave function, certain orbitals are sequestered into two subspaces that permit a maximum number of occupations or holes, respectively, in any given configuration, thereby reducing the total number of possible configurations. Subsequent second-order perturbation theory captures additional dynamical correlation effects. Applications of the theory to the electronic structure of complexes involved in the activation of molecular oxygen by mono- and binuclear copper complexes are presented. In the mononuclear case, RASPT2 and CASPT2 provide very similar results. In the binuclear cases, however, only RASPT2 proves quantitatively useful, owing to the very large size of the necessary active space.
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Affiliation(s)
- Per Ake Malmqvist
- Department of Theoretical Chemistry, University of Lund, P.O. Box 124, S-221 00 Lund, Sweden
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24
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Maiti D, Woertink JS, Narducci Sarjeant AA, Solomon EI, Karlin KD. Copper Dioxygen Adducts: Formation of Bis(μ-oxo)dicopper(III) versus (μ-1,2)Peroxodicopper(II) Complexes with Small Changes in One Pyridyl-Ligand Substituent. Inorg Chem 2008; 47:3787-800. [DOI: 10.1021/ic702437c] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Debabrata Maiti
- Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218, and Department of Chemistry, Stanford University, Stanford, California 94305
| | - Julia S. Woertink
- Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218, and Department of Chemistry, Stanford University, Stanford, California 94305
| | - Amy A. Narducci Sarjeant
- Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218, and Department of Chemistry, Stanford University, Stanford, California 94305
| | - Edward I. Solomon
- Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218, and Department of Chemistry, Stanford University, Stanford, California 94305
| | - Kenneth D. Karlin
- Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218, and Department of Chemistry, Stanford University, Stanford, California 94305
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25
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Lewin JL, Heppner DE, Cramer CJ. Validation of density functional modeling protocols on experimental bis(μ-oxo)/μ-η2:η2-peroxo dicopper equilibria. J Biol Inorg Chem 2007; 12:1221-34. [PMID: 17710449 DOI: 10.1007/s00775-007-0290-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2007] [Accepted: 08/03/2007] [Indexed: 10/22/2022]
Abstract
The bis(mu-oxo)/mu-eta(2):eta(2)-peroxo equilibria for seven supported Cu(2)O(2) cores were studied with different hybrid and nonhybrid density functional theory models, namely, BLYP, mPWPW, TPSS, TPSSh, B3LYP, mPW1PW, and MPW1K. Supporting ligands 3,3'-iminobis(N,N-dimethylpropylamine), N,N,N',N',N''-pentamethyldipropylenetriamine, N-[2-(pyridin-2-yl)ethyl]-N,N,N'-trimethylpropane-1,3-diamine, bis[2-(2-pyridin-2-yl)ethyl]methylamine, bis[2-(4-methoxy-2-pyridin-2-yl)ethyl]methylamine, bis[2-(4-N,N-dimethylamino-2-pyridin-2-yl)ethyl]methylamine, and 1,4,7-triisopropyl-1,4,7-triazacyclononane were chosen on the basis of the availability of experimental data for comparison. Density functionals were examined with respect to their ability accurately to reproduce experimental properties, including, in particular, geometries and relative energies for the bis(mu-oxo) and side-on peroxo forms. While geometries from both hybrid and nonhybrid functionals were in good agreement with experiment, the incorporation of Hartree-Fock (HF) exchange in hybrid density functionals was found to have a large, degrading effect on predicted relative isomer energies. Specifically, hybrid functionals predicted the mu-eta(2):eta(2)-peroxo isomer to be too stable by roughly 5-10 kcal mol(-1) for each 10% of HF exchange incorporated into the model. Continuum solvation calculations predict electrostatic effects to favor bis(mu-oxo) isomers by 1-4 kcal mol(-1) depending on ligand size, with larger ligands having smaller differential solvation effects. Analysis of computed molecular partition functions suggests that nonzero measured entropies of isomerization are likely to be primarily associated with interactions between molecular solutes and their first solvation shell.
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Affiliation(s)
- John L Lewin
- Department of Chemistry and Supercomputer Institute, University of Minnesota, 207 Pleasant Street SE, Minneapolis, MN 55455, USA
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Cramer CJ, Kinal A, Włoch M, Piecuch P, Gagliardi L. Theoretical Characterization of End-On and Side-On Peroxide Coordination in Ligated Cu2O2 Models. J Phys Chem A 2006; 110:11557-68. [PMID: 17020270 DOI: 10.1021/jp064232h] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The relative energetics of mu-eta1:eta1 (trans end-on) and mu-eta2:eta2 (side-on) peroxo isomers of Cu2O2 fragments supported by 0, 2, 4, and 6 ammonia ligands have been computed with various density functional, coupled-cluster, and multiconfigurational protocols. There is substantial disagreement between the different levels for most cases, although completely renormalized coupled-cluster methods appear to offer the most reliable predictions. The significant biradical character of the end-on peroxo isomer proves problematic for the density functionals, while the demands on active space size and the need to account for interactions between different states in second-order perturbation theory prove challenging for the multireference treatments. In the latter case, it proved impossible to achieve any convincing convergence.
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Affiliation(s)
- Christopher J Cramer
- Department of Chemistry and Supercomputer Institute, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, USA
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27
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Siegbahn PEM. The performance of hybrid DFT for mechanisms involving transition metal complexes in enzymes. J Biol Inorg Chem 2006; 11:695-701. [PMID: 16830147 DOI: 10.1007/s00775-006-0137-2] [Citation(s) in RCA: 192] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2006] [Accepted: 06/14/2006] [Indexed: 10/24/2022]
Abstract
The accuracy of density functional theory with the B3LYP functional is reviewed for systems of relevance to transition-metal-containing enzymes. Calculated energies are commonly within 3-5 kcal/mol of the correct values; however, some exceptions have appeared in the literature and are discussed here. For example, the binding of NO and that of O(2) to metal centers have for some time been known to be underestimated. Most barriers for chemical reactions are overestimated except those involving hydrogen (or proton) transfer, which instead tend to be underestimated. A minor general improvement of the accuracy can probably be obtained by slightly reducing the amount of exact exchange in the B3LYP functional.
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Affiliation(s)
- Per E M Siegbahn
- Department of Physics, AlbaNova University Center, Stockholm University, 106 91 Stockholm, Sweden.
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28
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Bassan A, Blomberg MRA, Borowski T, Siegbahn PEM. Theoretical studies of enzyme mechanisms involving high-valent iron intermediates. J Inorg Biochem 2006; 100:727-43. [PMID: 16513176 DOI: 10.1016/j.jinorgbio.2006.01.015] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2005] [Revised: 01/12/2006] [Accepted: 01/16/2006] [Indexed: 01/21/2023]
Abstract
Recent theoretical contributions to the elucidation of mechanisms for iron containing enzymes are reviewed. The method used in most of these studies is hybrid density functional theory with the B3LYP functional. Three classes of enzymes are considered, the mononuclear non-heme enzymes, enzymes containing iron dimers, and heme-containing enzymes. Mechanisms for both dioxygen and substrate activations are discussed. The reactions usually go through two half-cycles, where a high-valent intermediate Fe(IV)O species is created in the first half-cycle, and the substrate reactions involving this intermediate occur in the second half-cycle. Similarities between the three classes of enzymes dominate, but significant differences also exist.
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Affiliation(s)
- Arianna Bassan
- Department of Physics, Stockholm University, AlbaNova University Center, Stockholm Center for Physics, Astronomy and Biotechnology, SE-106 91, Stockholm, Sweden
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29
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Aboelella NW, Gherman BF, Hill LMR, York JT, Holm N, Young VG, Cramer CJ, Tolman WB. Effects of thioether substituents on the O2 reactivity of beta-diketiminate-Cu(I) complexes: probing the role of the methionine ligand in copper monooxygenases. J Am Chem Soc 2006; 128:3445-58. [PMID: 16522125 PMCID: PMC2593856 DOI: 10.1021/ja057745v] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The activation of dioxygen by dopamine beta-monooxygenase (DbetaM) and peptidylglycine alpha-hydroxylating monooxygenase (PHM) is postulated to occur at a copper site ligated by two histidine imidazoles and a methionine thioether, which is unusual because such thioether ligation is not present in other O2-activating copper proteins. To assess the possible role of the thioether ligand in O2 activation by DbetaM and PHM, two new ligands comprising beta-diketiminates with thioether substituents were synthesized and Cu(I) and Cu(II) complexes were isolated. The Cu(II) compounds are monomeric and exhibit intramolecular thioether coordination. While the Cu(I) complexes exhibit a multinuclear topology in the solid state, variable-temperature 1H NMR studies implicate equilibria in solution, possibly including monomers with intramolecular thioether coordination that are structurally defined by DFT calculations. Low-temperature oxygenation of solutions of the Cu(I) complexes generates stable 1:1 Cu/O2 adducts, which on the basis of combined experimental and theoretical studies adopt side-on "eta(2)" structures with negligible Cu-thioether bonding and significant peroxo-Cu(III) character. In contrast to previously reported findings with related ligands lacking the thioether group, however (cf., Aboelella; et al. J. Am. Chem. Soc. 2004, 126, 16896), purging the solutions of the thioether-containing adducts with argon results in conversion to bis(mu-oxo)dicopper(III) species. A role for the thioether in promoting loss of O2 from the 1:1 Cu/O2 adduct and facilitating trapping of the resulting Cu(I) complex to yield the bis(mu-oxo) species is proposed, and the possible relevance of this role to that of the methionine in the active sites of DbetaM and PHM is discussed.
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Affiliation(s)
- Nermeen W Aboelella
- Department of Chemistry, Center for Metals in Biocatalysis, and Minnesota Supercomputer Institute, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, USA
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Cramer CJ, Włoch M, Piecuch P, Puzzarini C, Gagliardi L. Theoretical Models on the Cu2O2 Torture Track: Mechanistic Implications for Oxytyrosinase and Small-Molecule Analogues. J Phys Chem A 2006; 110:1991-2004. [PMID: 16451035 DOI: 10.1021/jp056791e] [Citation(s) in RCA: 159] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Accurately describing the relative energetics of alternative bis(mu-oxo) and mu-eta2:eta2 peroxo isomers of Cu2O2 cores supported by 0, 2, 4, and 6 ammonia ligands is remarkably challenging for a wide variety of theoretical models, primarily owing to the difficulty of maintaining a balanced description of rapidly changing dynamical and nondynamical electron correlation effects and a varying degree of biradical character along the isomerization coordinate. The completely renormalized coupled-cluster level of theory including triple excitations and extremely efficient pure density functional levels of theory quantitatively agree with one another and also agree qualitatively with experimental results for Cu2O2 cores supported by analogous but larger ligands. Standard coupled-cluster methods, such as CCSD(T), are in most cases considerably less accurate and exhibit poor convergence in predicted relative energies. Hybrid density functionals significantly underestimate the stability of the bis(mu-oxo) form, with the magnitude of the error being directly proportional to the percentage Hartree-Fock exchange in the functional. Single-root CASPT2 multireference second-order perturbation theory, by contrast, significantly overestimates the stability of bis(mu-oxo) isomers. Implications of these results for modeling the mechanism of C-H bond activation by supported Cu2O2 cores, like that found in the active site of oxytyrosinase, are discussed.
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Affiliation(s)
- Christopher J Cramer
- Department of Chemistry and Supercomputer Institute, University of Minnesota, 207 Pleasant St. SE, Minneapolis, Minnesota 55455, USA.
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31
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Kim YJ, No JK, Lee JH, Chung HY. 4,4'-Dihydroxybiphenyl as a new potent tyrosinase inhibitor. Biol Pharm Bull 2005; 28:323-7. [PMID: 15684492 DOI: 10.1248/bpb.28.323] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The color of mammalian skin is determined by many factors, for which visible ones are the degree and distribution of melanin pigmentation. Because tyrosinase, (polyphenol oxidase) is the key enzyme for melanin biosynthesis, the use of various tyrosinase inhibitors is a common practice for whitening purpose in cosmetics. In the present study, the inhibition of tyrosinase by 4,4'-dihydroxybiphenyl (44'-BP) was investigated. In addition to tyrosinase inhibiting activity, melanin biosynthesis was assessed in B16F10 melanoma cells (B16 cells). The results showed that 44'-BP exhibits a strong anti-tyrosinase activity with IC50=1.91 microM. The kinetic analysis of tyrosinase inhibition revealed that 44'-BP acts a competitive inhibitor (Ki=4.0 x 10(-4) M at 2.5 microM and Ki =21 x 10(-5) M at 5 microM). Furthermore, data on melanin biosynthesis indicated that the amount of melanin was clearly suppressed by 44'-BP.
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Affiliation(s)
- You Jung Kim
- Department of Cosmetology, Pusan Women's College, Busanjin-Gu, Busan, 607-843, Korea
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Siegbahn PEM. The catalytic cycle of catechol oxidase. J Biol Inorg Chem 2004; 9:577-90. [PMID: 15185133 DOI: 10.1007/s00775-004-0551-2] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2003] [Accepted: 04/15/2004] [Indexed: 10/26/2022]
Abstract
Hybrid density functional theory with the B3LYP functional has been used to investigate the catalytic mechanism of catechol oxidase. Catechol oxidase belongs to a class of enzymes that has a copper dimer with histidine ligands at the active site. Another member of this class is tyrosinase, which has been studied by similar methods previously. An important advantage for the present study compared to the one for tyrosinase is that X-ray crystal structures exist for catechol oxidase. The most critical step in the mechanism for catechol oxidase is where the peroxide O-O bond is cleaved. In the suggested mechanism this cleavage occurs in concert with a proton transfer from the substrate. Shortly after the transition state is passed there is another proton transfer from the substrate, which completes the formation of a water molecule. An important feature of the mechanism, like the one for tyrosinase, is that no proton transfers to or from residues outside the metal complex are needed. The calculated energetics is in reasonable agreement with experiments. Comparisons are made to other similar enzymes studied previously.
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Affiliation(s)
- Per E M Siegbahn
- Department of Physics, Stockholm Centre for Physics, Astronomy and Biotechnology, Stockholm University, 10691 Stockholm, Sweden.
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Mirica LM, Ottenwaelder X, Stack TDP. Structure and Spectroscopy of Copper−Dioxygen Complexes. Chem Rev 2004; 104:1013-45. [PMID: 14871148 DOI: 10.1021/cr020632z] [Citation(s) in RCA: 1098] [Impact Index Per Article: 54.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Liviu M Mirica
- Department of Chemistry, Stanford University, Stanford, California 94305, USA
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35
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Affiliation(s)
- Elizabeth A Lewis
- Department of Chemistry and Center for Metals in Biocatalysis, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, USA
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