1
|
Mena LD, Baumgartner MT. Chalcogen Atoms as Electron Donors in Proton-Coupled Electron Transfer Reactions. J Am Chem Soc 2022; 144:15922-15927. [PMID: 36018719 DOI: 10.1021/jacs.2c05602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Proton-coupled electron transfer (PCET) reactions are crucial for the optimal functioning of a broad scope of chemical and biological processes. In this report, we present an unprecedented type of concerted PCET (cPCET), in which a chalcogen atom acts as the electron donor. The nature of this mechanism is key for understanding the reactivity of different radical-trapping antioxidants having heavy chalcogens (S, Se, or Te) in their structures. Moreover, this chalcogen-assisted cPCET is likely to be occurring in multiple systems of biological interest.
Collapse
Affiliation(s)
- Leandro D Mena
- QUIAMM-INBIOTEC-Departamento de Química, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Mar del Plata B7600, Argentina
| | - María T Baumgartner
- INFIQC, Departamento de Química Orgánica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba X5000, Argentina
| |
Collapse
|
2
|
Alfieri ML, Panzella L, Amorati R, Cariola A, Valgimigli L, Napolitano A. Role of Sulphur and Heavier Chalcogens on the Antioxidant Power and Bioactivity of Natural Phenolic Compounds. Biomolecules 2022; 12:90. [PMID: 35053239 PMCID: PMC8774257 DOI: 10.3390/biom12010090] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 01/03/2022] [Accepted: 01/04/2022] [Indexed: 02/06/2023] Open
Abstract
The activity of natural phenols is primarily associated to their antioxidant potential, but is ultimately expressed in a variety of biological effects. Molecular scaffold manipulation of this large variety of compounds is a currently pursued approach to boost or modulate their properties. Insertion of S/Se/Te containing substituents on phenols may increase/decrease their H-donor/acceptor ability by electronic and stereo-electronic effects related to the site of substitution and geometrical constrains. Oxygen to sulphur/selenium isosteric replacement in resveratrol or ferulic acid leads to an increase in the radical scavenging activity with respect to the parent phenol. Several chalcogen-substituted phenols inspired by Vitamin E and flavonoids have been prepared, which in some cases prove to be chain-breaking antioxidants, far better than the natural counterparts. Conjugation of catechols with biological thiols (cysteine, glutathione, dihydrolipoic acid) is easily achieved by addition to the corresponding ortho-quinones. Noticeable examples of compounds with potentiated antioxidant activities are the human metabolite 5-S-cysteinyldopa, with high iron-induced lipid peroxidation inhibitory activity, due to strong iron (III) binding, 5-S-glutathionylpiceatannol a most effective inhibitor of nitrosation processes, and 5-S-lipoylhydroxytyrosol, and its polysulfides that proved valuable oxidative-stress protective agents in various cellular models. Different methodologies have been used for evaluation of the antioxidant power of these compounds against the parent compounds. These include kinetics of inhibition of lipid peroxidation alkylperoxyl radicals, common chemical assays of radical scavenging, inhibition of the OH• mediated hydroxylation/oxidation of model systems, ferric- or copper-reducing power, scavenging of nitrosating species. In addition, computational methods allowed researchers to determine the Bond Dissociation Enthalpy values of the OH groups of chalcogen modified phenolics and predict the best performing derivative. Finally, the activity of Se and Te containing compounds as mimic of glutathione peroxidase has been evaluated, together with other biological activities including anticancer action and (neuro)protective effects in various cellular models. These and other achievements are discussed and rationalized to guide future development in the field.
Collapse
Affiliation(s)
- Maria Laura Alfieri
- Department of Chemical Sciences, University of Naples “Federico II”, Via Cintia 21, I-80126 Naples, Italy; (M.L.A.); (L.P.)
| | - Lucia Panzella
- Department of Chemical Sciences, University of Naples “Federico II”, Via Cintia 21, I-80126 Naples, Italy; (M.L.A.); (L.P.)
| | - Riccardo Amorati
- Department of Chemistry “Giacomo Ciamician”, University of Bologna, Via S. Giacomo 11, I-40126 Bologna, Italy; (R.A.); (A.C.)
| | - Alice Cariola
- Department of Chemistry “Giacomo Ciamician”, University of Bologna, Via S. Giacomo 11, I-40126 Bologna, Italy; (R.A.); (A.C.)
| | - Luca Valgimigli
- Department of Chemistry “Giacomo Ciamician”, University of Bologna, Via S. Giacomo 11, I-40126 Bologna, Italy; (R.A.); (A.C.)
| | - Alessandra Napolitano
- Department of Chemical Sciences, University of Naples “Federico II”, Via Cintia 21, I-80126 Naples, Italy; (M.L.A.); (L.P.)
| |
Collapse
|
3
|
Protective Role of Natural and Semi-Synthetic Tocopherols on TNFα-Induced ROS Production and ICAM-1 and Cl-2 Expression in HT29 Intestinal Epithelial Cells. Antioxidants (Basel) 2021; 10:antiox10020160. [PMID: 33499140 PMCID: PMC7911239 DOI: 10.3390/antiox10020160] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 12/31/2020] [Accepted: 01/19/2021] [Indexed: 12/12/2022] Open
Abstract
Vitamin E, a fat-soluble compound, possesses both antioxidant and non-antioxidant properties. In this study we evaluated, in intestinal HT29 cells, the role of natural tocopherols, α-Toc and δ-Toc, and two semi-synthetic derivatives, namely bis-δ-Toc sulfide (δ-Toc)2S and bis-δ-Toc disulfide (δ-Toc)2S2, on TNFα-induced oxidative stress, and intercellular adhesion molecule-1 (ICAM-1) and claudin-2 (Cl-2) expression. The role of tocopherols was compared to that of N-acetylcysteine (NAC), an antioxidant precursor of glutathione synthesis. The results show that all tocopherol containing derivatives used, prevented TNFα-induced oxidative stress and the increase of ICAM-1 and Cl-2 expression, and that (δ-Toc)2S and (δ-Toc)2S2 are more effective than δ-Toc and α-Toc. The beneficial effects demonstrated were due to tocopherol antioxidant properties, but suppression of TNFα-induced Cl-2 expression seems not only to be related with antioxidant ability. Indeed, while ICAM-1 expression is strongly related to the intracellular redox state, Cl-2 expression is TNFα-up-regulated by both redox and non-redox dependent mechanisms. Since ICAM-1 and Cl-2 increase intestinal bowel diseases, and cause excessive recruitment of immune cells and alteration of the intestinal barrier, natural and, above all, semi-synthetic tocopherols may have a potential role as a therapeutic support against intestinal chronic inflammation, in which TNFα represents an important proinflammatory mediator.
Collapse
|
4
|
Jayasree EG, Sukumar C. A DFT study on the cleavage of dichalcogenide bridges in cystines and selenocystines: Effect of hydrogen bonding. Inorganica Chim Acta 2020. [DOI: 10.1016/j.ica.2020.119897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
5
|
|
6
|
Viglianisi C, Menichetti S. Chain Breaking Antioxidant Activity of Heavy (S, Se, Te) Chalcogens Substituted Polyphenols. Antioxidants (Basel) 2019; 8:antiox8100487. [PMID: 31623080 PMCID: PMC6826409 DOI: 10.3390/antiox8100487] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 10/12/2019] [Accepted: 10/15/2019] [Indexed: 12/13/2022] Open
Abstract
Polyphenols are probably the most important family of natural and synthetic chain-breaking antioxidants. Since long ago, chemists have studied how structural (bioinspired) modifications can improve the antioxidant activity of these compounds in terms of reaction rate with radical reactive oxygen species (ROS), catalytic character, multi-defence action, hydrophilicity/lipophilicity, biodistribution etc. In this framework, we will discuss the effect played on the overall antioxidant profile by the insertion of heavy chalcogens (S, Se and Te) in the phenolic skeleton.
Collapse
Affiliation(s)
- Caterina Viglianisi
- Department of Chemistry "Ugo Schiff", University of Florence, Via Della Lastruccia 3-13, 50019 Sesto Fiorentino, Italy.
| | - Stefano Menichetti
- Department of Chemistry "Ugo Schiff", University of Florence, Via Della Lastruccia 3-13, 50019 Sesto Fiorentino, Italy.
| |
Collapse
|
7
|
Viglianisi C, Vasa K, Tanini D, Capperucci A, Amorati R, Valgimigli L, Baschieri A, Menichetti S. Ditocopheryl Sulfides and Disulfides: Synthesis and Antioxidant Profile. Chemistry 2019; 25:9108-9116. [PMID: 31017702 DOI: 10.1002/chem.201901537] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Indexed: 12/14/2022]
Abstract
Symmetrical ditocopheryl disulfides (Toc)2 S2 and symmetrical and unsymmetrical ditocopheryl sulfides (Toc)2 S were simply prepared under remarkably mild conditions with complete control of the regiochemistry by using δ-, γ-, and β-tocopheryl-N-thiophthalimides (Toc-NSPht) as common starting materials. The roles of sulfur atom(s), H-bond and aryl ring substitution pattern on the antioxidant profile of these new compounds, which were assembled by linking together two tocopheryl units, are also discussed.
Collapse
Affiliation(s)
- Caterina Viglianisi
- Department of Chemistry "Ugo Schiff", University of Florence, Via Della Lastruccia 3-13, Sesto Fiorentino, Firenze, Italy
| | - Kristian Vasa
- Department of Chemistry "Ugo Schiff", University of Florence, Via Della Lastruccia 3-13, Sesto Fiorentino, Firenze, Italy
| | - Damiano Tanini
- Department of Chemistry "Ugo Schiff", University of Florence, Via Della Lastruccia 3-13, Sesto Fiorentino, Firenze, Italy
| | - Antonella Capperucci
- Department of Chemistry "Ugo Schiff", University of Florence, Via Della Lastruccia 3-13, Sesto Fiorentino, Firenze, Italy
| | - Riccardo Amorati
- Department of Chemistry "G. Ciamician", University of Bologna, Via S. Giacomo 11, 40126, Bologna, Italy
| | - Luca Valgimigli
- Department of Chemistry "G. Ciamician", University of Bologna, Via S. Giacomo 11, 40126, Bologna, Italy
| | - Andrea Baschieri
- Department of Chemistry "G. Ciamician", University of Bologna, Via S. Giacomo 11, 40126, Bologna, Italy
| | - Stefano Menichetti
- Department of Chemistry "Ugo Schiff", University of Florence, Via Della Lastruccia 3-13, Sesto Fiorentino, Firenze, Italy
| |
Collapse
|
8
|
Kunert R, Philouze C, Jarjayes O, Thomas F. Stable M(II)-Radicals and Nickel(III) Complexes of a Bis(phenol) N-Heterocyclic Carbene Chelated to Group 10 Metal Ions. Inorg Chem 2019; 58:8030-8044. [PMID: 31185559 DOI: 10.1021/acs.inorgchem.9b00784] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The tetradentate ligand based on (1-imidazolium-3,5-di tert-butylphenol) units was prepared and chelated to group 10 metal ions (Ni(II), Pd(II), and Pt(II)), affording complexes 1, 2, and 3, respectively. The X-ray crystal structures of 1-3 show a square planar metal ion coordinated to two N-heterocyclic carbenes and two phenolate moieties. The cyclic voltammetry curves of complexes 1-3 show two reversible oxidation waves in the range 0.11-0.21 V ( E1/21) and 0.55-0.65 V ( E1/22) vs Fc+/Fc, which are assigned to the successive oxidations of the phenolate moieties. One-electron oxidation affords mononuclear ( S = 1/2) systems. Complex 1+·SbF6- was remarkably stable, and its structure was characterized. The coordination sphere is slightly dissymmetric, while the typical patterns of phenoxyl radicals were observed within the ligand framework. Complex 1+ exhibits a rhombic signal at g = 2.087, 2.016, and 1.992, confirming its predominant phenoxyl radical character. The g-values are slightly smaller for 2+ (2.021, 2.008, and 1.983) and larger for 3+ (2.140, 1.999, and 1.885) yet consistent with phenoxyl radical species. The electronic spectra of 1+-3+ display an intervalence charge-transfer (IVCT) transition at 2396, 2600, and 2294 nm, respectively. Its intensity supports the description of cations 1+ and 3+ as mixed-valent (Class II/III) compounds according to the Robin Day classification. Complex 2+ behaves as a mixed-valent class II radical compound. In the presence of pyridine, radical species 1+ is successively converted into stable mono and bis(adducts), which are both Ni(III) complexes. Dications 1+2-3+2 were prepared electrochemically. They are electron paramagnetic resonance (EPR)-silent and do not show IVCT transition in their NIR spectra, consistent with a bis(radical) formulation. The proposed electronic structures are fully supported by density functional theory calculations.
Collapse
Affiliation(s)
- Romain Kunert
- Université Grenoble Alpes , UMR CNRS-5250, Département de Chimie Moléculaire , Grenoble F-38000 , France
| | - Christian Philouze
- Université Grenoble Alpes , UMR CNRS-5250, Département de Chimie Moléculaire , Grenoble F-38000 , France
| | - Olivier Jarjayes
- Université Grenoble Alpes , UMR CNRS-5250, Département de Chimie Moléculaire , Grenoble F-38000 , France
| | - Fabrice Thomas
- Université Grenoble Alpes , UMR CNRS-5250, Département de Chimie Moléculaire , Grenoble F-38000 , France
| |
Collapse
|
9
|
Amorati R, Baschieri A, Valgimigli L. The role of sulfur and heavier chalcogens in the chemistry of antioxidants. PHOSPHORUS SULFUR 2019. [DOI: 10.1080/10426507.2019.1602620] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- Riccardo Amorati
- Department of Chemistry “G. Ciamician”, University of Bologna, Bologna, Italy
| | - Andrea Baschieri
- Department of Chemistry “G. Ciamician”, University of Bologna, Bologna, Italy
| | - Luca Valgimigli
- Department of Chemistry “G. Ciamician”, University of Bologna, Bologna, Italy
| |
Collapse
|
10
|
Abstract
Many artificial enzymes that catalyze redox reactions have important energy, environmental, and medical applications. Native metalloenzymes use a set of redox-active amino acids and cofactors as redox centers, with a potential range between -700 and +800 mV versus standard hydrogen electrode (SHE, all reduction potentials are versus SHE). The redox potentials and the orientation of redox centers in native metalloproteins are optimal for their redox chemistry. However, the limited number and potential range of native redox centers challenge the design and optimization of novel redox chemistry in metalloenzymes. Artificial metalloenzymes use non-native redox centers and could go far beyond the natural range of redox potentials for novel redox chemistry. In addition to designing protein monomers, strategies for increasing the electron transfer rate in self-assembled protein complexes and protein-electrode or -nanomaterial interfaces will be discussed. Redox reactions in proteins occur on redox active amino acid residues (Tyr, Trp, Met, Cys, etc.) and cofactors (iron sulfur clusters, flavin, heme, etc.). The redox potential of these redox centers cover a ∼1.5 V range and is optimized for their specific functions. Despite recent progress, tuning the redox potential for amino acid residues or cofactors remains challenging. Many redox-active unnatural amino acids (UAAs) can be incorporated into protein via genetic codon expansion. Their redox potentials extend the range of physiologically relevant potentials. Indeed, installing new redox cofactors with fined-tuned redox potentials is essential for designing novel redox enzymes. By combining UAA and redox cofactor incorporation, we harnessed light energy to reduce CO2 in a fluorescent protein, mimicking photosynthetic apparatus in nature. Manipulating the position and reduction potential of redox centers inside proteins is important for optimizing the electron transfer rate and the activity of artificial enzymes. Learning from the native electron transfer complex, protein-protein interactions can be enhanced by increasing the electrostatic interaction between proteins. An artificial oxidase showed close to native enzyme activity with optimized interaction with electron transfer partner and increased electron transfer efficiency. In addition to the de novo design of protein-protein interaction, protein self-assembly methods using scaffolds, such as proliferating cell nuclear antigen, to efficiently anchor enzymes and their redox partners. The self-assembly process enhances electron transfer efficiency and enzyme activity by bringing redox centers into close proximity of each other. In addition to protein self-assembly, protein-electrode or protein-nanomaterial self-assembly can also promote efficient electron transfer from inorganic materials to enzyme active sites. Such hybrid systems combine the efficiency of enzyme reactions and the robustness of electrodes or nanomaterials, often with advantageous catalytic activities. By combining these strategies, we can not only mimic some of nature's most fascinating reactions, such as photosynthesis and aerobic respiration, but also transcend nature toward environmental, energy, and health applications.
Collapse
Affiliation(s)
- Yang Yu
- Department of Biochemical Engineering and Institute for Synthetic Biosystem, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, 5 Zhongguancun South Street, Haidian
District, Beijing 100081, China
| | - Xiaohong Liu
- Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Chaoyang District, Beijing 100101, China
| | - Jiangyun Wang
- Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Chaoyang District, Beijing 100101, China
| |
Collapse
|
11
|
Gordon JB, Vilbert AC, Siegler MA, Lancaster KM, Moënne-Loccoz P, Goldberg DP. A Nonheme Thiolate-Ligated Cobalt Superoxo Complex: Synthesis and Spectroscopic Characterization, Computational Studies, and Hydrogen Atom Abstraction Reactivity. J Am Chem Soc 2019; 141:3641-3653. [PMID: 30776222 DOI: 10.1021/jacs.8b13134] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The synthesis and characterization of a Co(II) dithiolato complex Co(Me3TACN)(S2SiMe2) (1) are reported. Reaction of 1 with O2 generates a rare thiolate-ligated cobalt-superoxo species Co(O2)(Me3TACN)(S2SiMe2) (2) that was characterized spectroscopically and structurally by resonance Raman, EPR, and X-ray absorption spectroscopies as well as density functional theory. Metal-superoxo species are proposed to S-oxygenate metal-bound thiolate donors in nonheme thiol dioxygenases, but 2 does not lead to S-oxygenation of the intramolecular thiolate donors and does not react with exogenous sulfur donors. However, complex 2 is capable of oxidizing the O-H bonds of 2,2,6,6-tetramethylpiperidin-1-ol derivatives via H atom abstraction. Complementary proton-coupled electron-transfer reactivity is seen for 2 with separated proton/reductant pairs. The reactivity studies indicate that 2 can abstract H atoms from weak X-H bonds with bond dissociation free energy (BDFE) ≤ 70 kcal mol-1. DFT calculations predict that the putative Co(OOH) product has an O-H BDFE = 67 kcal mol-1, which matches the observed pattern of reactivity seen for 2. These data provide new information regarding the selectivity of S-oxygenation versus H atom abstraction in thiolate-ligated nonheme metalloenzymes that react with O2.
Collapse
Affiliation(s)
- Jesse B Gordon
- Department of Chemistry , The Johns Hopkins University , 3400 North Charles Street , Baltimore , Maryland 21218 , United States
| | - Avery C Vilbert
- Department of Chemistry and Chemical Biology, Baker Laboratory , Cornell University , Ithaca , New York 14853 , United States
| | - Maxime A Siegler
- Department of Chemistry , The Johns Hopkins University , 3400 North Charles Street , Baltimore , Maryland 21218 , United States
| | - Kyle M Lancaster
- Department of Chemistry and Chemical Biology, Baker Laboratory , Cornell University , Ithaca , New York 14853 , United States
| | - Pierre Moënne-Loccoz
- Department of Biochemistry & Molecular Biology , Oregon Health & Science University , Portland , Oregon 97239-3098 , United States
| | - David P Goldberg
- Department of Chemistry , The Johns Hopkins University , 3400 North Charles Street , Baltimore , Maryland 21218 , United States
| |
Collapse
|
12
|
Chen L, Naowarojna N, Chen B, Xu M, Quill M, Wang J, Deng Z, Zhao C, Liu P. Mechanistic Studies of a Nonheme Iron Enzyme OvoA in Ovothiol Biosynthesis Using a Tyrosine Analogue, 2-Amino-3-(4-hydroxy-3-(methoxyl) phenyl) Propanoic Acid (MeOTyr). ACS Catal 2018. [DOI: 10.1021/acscatal.8b03903] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Li Chen
- Key Laboratory of Combinatory Biosynthesis and Drug Discovery, Ministry of Education, School of Pharmaceutical Sciences, Wuhan University, Hubei 430072, People’s Republic of China
- Department of Chemistry, Boston University, 590 Commonwealth Avenue, Boston, Massachusetts 02215, United States
| | - Nathchar Naowarojna
- Department of Chemistry, Boston University, 590 Commonwealth Avenue, Boston, Massachusetts 02215, United States
| | - Bin Chen
- Key Laboratory of Combinatory Biosynthesis and Drug Discovery, Ministry of Education, School of Pharmaceutical Sciences, Wuhan University, Hubei 430072, People’s Republic of China
| | - Meiling Xu
- Department of Chemistry, Boston University, 590 Commonwealth Avenue, Boston, Massachusetts 02215, United States
| | - Melissa Quill
- Department of Chemistry, Boston University, 590 Commonwealth Avenue, Boston, Massachusetts 02215, United States
| | - Jiangyun Wang
- Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, People’s Republic of China
| | - Zixin Deng
- Key Laboratory of Combinatory Biosynthesis and Drug Discovery, Ministry of Education, School of Pharmaceutical Sciences, Wuhan University, Hubei 430072, People’s Republic of China
| | - Changming Zhao
- Key Laboratory of Combinatory Biosynthesis and Drug Discovery, Ministry of Education, School of Pharmaceutical Sciences, Wuhan University, Hubei 430072, People’s Republic of China
- Department of Chemistry, Boston University, 590 Commonwealth Avenue, Boston, Massachusetts 02215, United States
| | - Pinghua Liu
- Department of Chemistry, Boston University, 590 Commonwealth Avenue, Boston, Massachusetts 02215, United States
| |
Collapse
|
13
|
Colomban C, Philouze C, Molton F, Leconte N, Thomas F. Copper(II) complexes of N3O ligands as models for galactose oxidase: Effect of variation of steric bulk of coordinated phenoxyl moiety on the radical stability and spectroscopy. Inorganica Chim Acta 2018. [DOI: 10.1016/j.ica.2017.09.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
14
|
Chen L, Naowarojna N, Song H, Wang S, Wang J, Deng Z, Zhao C, Liu P. Use of a Tyrosine Analogue To Modulate the Two Activities of a Nonheme Iron Enzyme OvoA in Ovothiol Biosynthesis, Cysteine Oxidation versus Oxidative C-S Bond Formation. J Am Chem Soc 2018; 140:4604-4612. [PMID: 29544051 PMCID: PMC5884719 DOI: 10.1021/jacs.7b13628] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Ovothiol is a histidine thiol derivative. The biosynthesis of ovothiol involves an extremely efficient trans-sulfuration strategy. The nonheme iron enzyme OvoA catalyzed oxidative coupling between cysteine and histidine is one of the key steps. Besides catalyzing the oxidative coupling between cysteine and histidine, OvoA also catalyzes the oxidation of cysteine to cysteine sulfinic acid (cysteine dioxygenase activity). Thus far, very little mechanistic information is available for OvoA-catalysis. In this report, we measured the kinetic isotope effect (KIE) in OvoA-catalysis using the isotopically sensitive branching method. In addition, by replacing an active site tyrosine (Tyr417) with 2-amino-3-(4-hydroxy-3-(methylthio)phenyl)propanoic acid (MtTyr) through the amber suppressor mediated unnatural amino acid incorporation method, the two OvoA activities (oxidative coupling between cysteine and histidine, and cysteine dioxygenase activity) can be modulated. These results suggest that the two OvoA activities branch out from a common intermediate and that the active site tyrosine residue plays some key roles in controlling the partitioning between these two pathways.
Collapse
Affiliation(s)
- Li Chen
- Key Laboratory of Combinatory Biosynthesis and Drug Discovery, Ministry of Education, School of Pharmaceutical Sciences, Wuhan University, Hubei 430072, People’s Republic of China
- Department of Chemistry, Boston University, Boston, Massachusetts 02215, United States
| | - Nathchar Naowarojna
- Department of Chemistry, Boston University, Boston, Massachusetts 02215, United States
| | - Heng Song
- Department of Chemistry, Boston University, Boston, Massachusetts 02215, United States
- College of Chemistry and Molecular Sciences, Wuhan University, Hubei 430072, People’s Republic of China
| | - Shu Wang
- Department of Chemistry, Boston University, Boston, Massachusetts 02215, United States
| | - Jiangyun Wang
- Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, People’s Republic of China
| | - Zixin Deng
- Key Laboratory of Combinatory Biosynthesis and Drug Discovery, Ministry of Education, School of Pharmaceutical Sciences, Wuhan University, Hubei 430072, People’s Republic of China
| | - Changming Zhao
- Key Laboratory of Combinatory Biosynthesis and Drug Discovery, Ministry of Education, School of Pharmaceutical Sciences, Wuhan University, Hubei 430072, People’s Republic of China
- Department of Chemistry, Boston University, Boston, Massachusetts 02215, United States
| | - Pinghua Liu
- Department of Chemistry, Boston University, Boston, Massachusetts 02215, United States
| |
Collapse
|
15
|
Baschieri A, Pulvirenti L, Muccilli V, Amorati R, Tringali C. Chain-breaking antioxidant activity of hydroxylated and methoxylated magnolol derivatives: the role of H-bonds. Org Biomol Chem 2018; 15:6177-6184. [PMID: 28695220 DOI: 10.1039/c7ob01195d] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Chemical modification of magnolol, an uncommon dimeric neolignan contained in Magnolia genus trees, provides a unique array of polyphenols having interesting biological activity potentially related to radical scavenging. The chain-breaking antioxidant activity of four new hydroxylated and methoxylated magnolol derivatives was explored by experimental and computational methods. The measurement of the rate constant of the reaction with ROO˙ radicals (kinh) in an apolar solvent showed that the introduction of hydroxyl groups ortho to the phenolic OH in magnolol increased the kinh value, being 2.4 × 105 M-1 s-1 and 3.3 × 105 M-1 s-1 for the mono and the dihydroxy derivatives respectively (kinh of magnolol is 6.1 × 104 M-1 s-1). The di-methoxylated derivative is less reactive than magnolol (kinh = 1.1 × 104 M-1 s-1), while the insertion of both hydroxyl and methoxyl groups showed no effect (6.0 × 104 M-1 s-1). Infrared spectroscopy and theoretical calculations allowed a rationalization of these results and pointed out the crucial role of intramolecular H-bonds. We also show that a correct estimation of the rate constant of the reaction with ROO˙ radicals, by using BDE(OH) calculations, requires that the geometry of the radical is as close as possible to that of the parent phenol.
Collapse
Affiliation(s)
- Andrea Baschieri
- Department of Chemistry "G. Ciamician", University of Bologna, Via S. Giacomo 11, 40126 Bologna, Italy.
| | - Luana Pulvirenti
- Department of Chemical Sciences, University of Catania, Viale A. Doria 6, I-95125 Catania, Italy
| | - Vera Muccilli
- Department of Chemical Sciences, University of Catania, Viale A. Doria 6, I-95125 Catania, Italy
| | - Riccardo Amorati
- Department of Chemistry "G. Ciamician", University of Bologna, Via S. Giacomo 11, 40126 Bologna, Italy.
| | - Corrado Tringali
- Department of Chemical Sciences, University of Catania, Viale A. Doria 6, I-95125 Catania, Italy
| |
Collapse
|
16
|
Menichetti S, Amorati R, Meoni V, Tofani L, Caminati G, Viglianisi C. Role of Noncovalent Sulfur···Oxygen Interactions in Phenoxyl Radical Stabilization: Synthesis of Super Tocopherol-like Antioxidants. Org Lett 2016; 18:5464-5467. [DOI: 10.1021/acs.orglett.6b02557] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Stefano Menichetti
- Department
of Chemistry “U. Schiff”, University of Florence, Via della Lastruccia 13, 50019 Sesto Fiorentino, Italy
| | - Riccardo Amorati
- Department
of Chemistry “Ciamician”, University of Bologna, Via San Giacomo 11, 40126 Bologna, Italy
| | - Valentina Meoni
- Department
of Chemistry “U. Schiff”, University of Florence, Via della Lastruccia 13, 50019 Sesto Fiorentino, Italy
| | - Lorenzo Tofani
- Department
of Chemistry “U. Schiff”, University of Florence, Via della Lastruccia 13, 50019 Sesto Fiorentino, Italy
| | - Gabriella Caminati
- Department
of Chemistry “U. Schiff”, University of Florence, Via della Lastruccia 13, 50019 Sesto Fiorentino, Italy
- CSGI, University of Florence, Via della Lastruccia 3, 50019 Sesto Fiorentino, Italy
| | - Caterina Viglianisi
- Department
of Chemistry “U. Schiff”, University of Florence, Via della Lastruccia 13, 50019 Sesto Fiorentino, Italy
| |
Collapse
|
17
|
Viglianisi C, Amorati R, Di Pietro L, Menichetti S. A Straightforward Route to Potent Phenolic Chain-Breaking Antioxidants by Acid-Promoted Transposition of 1,4-Benzo[b]oxathiines to Dihydrobenzo[b]thiophenes. Chemistry 2015; 21:16639-45. [PMID: 26440303 DOI: 10.1002/chem.201502650] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Indexed: 12/25/2022]
Abstract
The transformation of simple phenols with limited antioxidant activity into potent chain-breaking antioxidants was achieved by a three-step protocol, consisting of the conversion of phenols into 1,4-benzo[b]oxathiines followed by an unprecedented acid-promoted transposition to o-hydroxydihydrobenzo[b]thiophenes, or dihydrobenzo[de]thiochromenes, starting from phenols or naphthols, respectively. These derivatives, bearing a benzo-fused heterocycle with a sulfide sulfur ortho to the phenolic OH, have a rate constant of reaction with alkylperoxyl radicals (kinh ) comparable to that of α-tocopherol. A solid rationale for the transposition mechanism as well as for the structure-antioxidant activity relationship is presented.
Collapse
Affiliation(s)
- Caterina Viglianisi
- Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia 3-13, 50019, Sesto Fiorentino, Firenze (Italy).
| | - Riccardo Amorati
- Department of Chemistry "G. Ciamician", University of Bologna, Via S. Giacomo 11, 40126 Bologna (Italy)
| | - Leonardo Di Pietro
- Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia 3-13, 50019, Sesto Fiorentino, Firenze (Italy)
| | - Stefano Menichetti
- Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia 3-13, 50019, Sesto Fiorentino, Firenze (Italy).
| |
Collapse
|
18
|
Houée-Lévin C, Bobrowski K, Horakova L, Karademir B, Schöneich C, Davies MJ, Spickett CM. Exploring oxidative modifications of tyrosine: An update on mechanisms of formation, advances in analysis and biological consequences. Free Radic Res 2015; 49:347-73. [DOI: 10.3109/10715762.2015.1007968] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
|
19
|
Tanini D, Panzella L, Amorati R, Capperucci A, Pizzo E, Napolitano A, Menichetti S, d'Ischia M. Resveratrol-based benzoselenophenes with an enhanced antioxidant and chain breaking capacity. Org Biomol Chem 2015; 13:5757-64. [DOI: 10.1039/c5ob00193e] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
One-pot selenenylation of resveratrol with Se(0) and SO2Cl2 leads to benzoselenophene derivatives with efficient Trolox-like antioxidant and chain breaking capacity.
Collapse
Affiliation(s)
- Damiano Tanini
- Department of Chemistry “Ugo Schiff”
- University of Florence
- I-50019 Sesto Fiorentino
- Italy
| | - Lucia Panzella
- Department of Chemical Sciences
- University of Naples “Federico II”
- I-80126 Naples
- Italy
| | - Riccardo Amorati
- Department of Chemistry “G. Ciamician”
- University of Bologna
- I-40126 Bologna
- Italy
| | - Antonella Capperucci
- Department of Chemistry “Ugo Schiff”
- University of Florence
- I-50019 Sesto Fiorentino
- Italy
| | - Elio Pizzo
- Department of Biology
- University of Naples “Federico II”
- I-80126 Naples
- Italy
| | - Alessandra Napolitano
- Department of Chemical Sciences
- University of Naples “Federico II”
- I-80126 Naples
- Italy
| | - Stefano Menichetti
- Department of Chemistry “Ugo Schiff”
- University of Florence
- I-50019 Sesto Fiorentino
- Italy
| | - Marco d'Ischia
- Department of Chemical Sciences
- University of Naples “Federico II”
- I-80126 Naples
- Italy
| |
Collapse
|
20
|
Viglianisi C, Marcantoni E, Carapacchi V, Menichetti S, Marsili L. A Base-Mediated Mild Sulfenylation of Indoles and Pyrrole with α-Acylthiones. European J Org Chem 2014. [DOI: 10.1002/ejoc.201402894] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
21
|
Viglianisi C, Sinni A, Menichetti S. Copper-Mediated One-Pot Access to 2,3-Dihydrobenzo[b][1,4]oxathiines fromo,o′-Dihydroxydisulfides. HETEROATOM CHEMISTRY 2014. [DOI: 10.1002/hc.21159] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Caterina Viglianisi
- Department of Chemistry ‘Ugo Schiff,’ University of Florence; Via della Lastruccia 3-13; I-50019 Sesto Fiorentino Italy
| | - Aidona Sinni
- Department of Chemistry ‘Ugo Schiff,’ University of Florence; Via della Lastruccia 3-13; I-50019 Sesto Fiorentino Italy
| | - Stefano Menichetti
- Department of Chemistry ‘Ugo Schiff,’ University of Florence; Via della Lastruccia 3-13; I-50019 Sesto Fiorentino Italy
| |
Collapse
|
22
|
Amorati R, Valgimigli L, Panzella L, Napolitano A, d’Ischia M. 5-S-Lipoylhydroxytyrosol, a Multidefense Antioxidant Featuring a Solvent-Tunable Peroxyl Radical-Scavenging 3-Thio-1,2-dihydroxybenzene Motif. J Org Chem 2013; 78:9857-64. [DOI: 10.1021/jo401522q] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Riccardo Amorati
- Department
of Chemistry “G. Ciamician”, University of Bologna, Via S. Giacomo 11, I-40126 Bologna, Italy
| | - Luca Valgimigli
- Department
of Chemistry “G. Ciamician”, University of Bologna, Via S. Giacomo 11, I-40126 Bologna, Italy
| | - Lucia Panzella
- Department
of Chemical Sciences, University of Naples “Federico II”, Via Cintia 4, I-80126, Naples, Italy
| | - Alessandra Napolitano
- Department
of Chemical Sciences, University of Naples “Federico II”, Via Cintia 4, I-80126, Naples, Italy
| | - Marco d’Ischia
- Department
of Chemical Sciences, University of Naples “Federico II”, Via Cintia 4, I-80126, Naples, Italy
| |
Collapse
|
23
|
Self-organization of non-amphiphilic molecules. Studies of thin films of long-chain homologous dialkylthioethers at the water/air interface. J Colloid Interface Sci 2013; 395:176-84. [PMID: 23380401 DOI: 10.1016/j.jcis.2012.12.055] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2012] [Revised: 12/25/2012] [Accepted: 12/26/2012] [Indexed: 11/21/2022]
Abstract
In contrast to classical surfactants, the knowledge about the self-organization of alkanes and their hydrophobic derivatives is still limited. In this paper, we present the results of the studies of self-assembly of long-chain dialkylthioethers at the air/water interface. The substitution of one methylene group by the thioether divalent sulfur introduces significant dipole moment to the alkane chain without affecting the hydrophobicity, which profoundly influences the self-assembly of these molecules. Depending on the location of the thioether group in the hydrophobic chain, the investigated molecules can form Langmuir monolayers, which are stabilized by the thioether-water H-bonds formation, or random multilayers. The structures of the monolayers were investigated with the application of Grazing Incidence X-ray Diffraction. To elucidate important structural differences between thioether and alkane monolalyers of the same hydrocarbon chain length, we applied the methods of quantum chemistry (ETS-NOCV calculations). It turned out that the introduction of one sulfur atom affects the distribution of electron density not only in the proximity of this atom but generally along the chain. The combination of experimental and calculation methods provides to the better understanding of the fundamental question of the self-organization of long-chain alkanes and their non-amphiphilic derivatives at interfaces.
Collapse
|
24
|
Hou X, Yuan WC, Fang DM, Luo SW, Wu ZJ. Unexpected [M-H + Na]+˙ radical ions in 3-isothiocyanato oxindoles detected by electrospray mass spectrometry. JOURNAL OF MASS SPECTROMETRY : JMS 2013; 48:344-347. [PMID: 23494790 DOI: 10.1002/jms.3144] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Revised: 11/17/2012] [Accepted: 11/20/2012] [Indexed: 06/01/2023]
|
25
|
Butsch K, Günther T, Klein A, Stirnat K, Berkessel A, Neudörfl J. Redox chemistry of copper complexes with various salen type ligands. Inorganica Chim Acta 2013. [DOI: 10.1016/j.ica.2012.08.016] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
26
|
Zhou Q, Hu M, Zhang W, Jiang L, Perrett S, Zhou J, Wang J. Probing the function of the Tyr-Cys cross-link in metalloenzymes by the genetic incorporation of 3-methylthiotyrosine. Angew Chem Int Ed Engl 2012. [PMID: 23197358 DOI: 10.1002/anie.201207229] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Qing Zhou
- Laboratory of Non-coding RNA, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Chaoyang District, Beijing 100101, China
| | | | | | | | | | | | | |
Collapse
|
27
|
Zhou Q, Hu M, Zhang W, Jiang L, Perrett S, Zhou J, Wang J. Probing the Function of the Tyr-Cys Cross-Link in Metalloenzymes by the Genetic Incorporation of 3-Methylthiotyrosine. Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201207229] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
28
|
Marcantoni E, Cipolletti R, Marsili L, Menichetti S, Properzi R, Viglianisi C. An Efficient Catalytic Method for Regioselective Sulfenylation of Electron-Rich Aza-Aromatics at Room Temperature. European J Org Chem 2012. [DOI: 10.1002/ejoc.201201100] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
29
|
Butsch K, Klein A, Nitsche S, Stirnat K, Hawkett JR, McInnes EJL, Bauer M. Generation and characterisation of the phenoxyl-radical containing Cu(II) complex [Cu(triaz)2]+ (triaz- = O,N chelating triazole-phenolate). Dalton Trans 2012; 41:11464-75. [PMID: 22895494 DOI: 10.1039/c2dt31369c] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The new copper complex [Cu(triaz)(2)] (Htriaz = 2,4-di-(tert-butyl)-6-(5-chloro-2H-benzo[d][1,2,3]triazol-2-yl)phenol) was investigated in detail by single crystal XRD, EPR-, UV/Vis-absorption-, CV-, and spectroelectrochemistry. The oxidised species [Cu(triaz)(2)](+) was characterised by UV/Vis spectroelectrochemistry and contains a phenoxyl-radical bound to Cu(II). This quite stable species was chemically generated by two different methods: aerial oxidation of a Cu(I) precursor in the presence of Htriaz (and base) or from [Cu(triaz)(2)] by adding a Cu(II) salt (disproportionation). The efficiency for the latter reaction has been studied by UV/Vis spectroscopy, XAS and catalytic test reactions (oxidation of benzyl alcohol).
Collapse
Affiliation(s)
- Katharina Butsch
- Universität zu Köln, Department für Chemie, Institut für Anorganische Chemie, Greinstrasse 6, D-50939 Köln, Germany
| | | | | | | | | | | | | |
Collapse
|
30
|
Viglianisi C, Bonaccorsi P, Simone L, Nassini L, Menichetti S. Copper-Mediated One-Pot Access to Benzo[b][1,4]thiazines from 2-N-Sulfonylaminoaryl Disulfides. European J Org Chem 2012. [DOI: 10.1002/ejoc.201200023] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
31
|
Viglianisi C, Simone L, Menichetti S. Copper‐Mediated One‐Pot Transformation of 2‐N‐Sulfonyl‐ aminoaryl Diselenides into Benzo[b][1,4]selenazines. Adv Synth Catal 2012. [DOI: 10.1002/adsc.201100587] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Caterina Viglianisi
- Dipartimento di Chimica “U. Schiff”, Polo Scientifico e Tecnologico Università di Firenze, Via della Lastruccia, 3‐13, 50019 Sesto Fiorentino, Italy, Fax. (+39)‐055‐457‐3531
| | - Lavinia Simone
- Dipartimento di Chimica “U. Schiff”, Polo Scientifico e Tecnologico Università di Firenze, Via della Lastruccia, 3‐13, 50019 Sesto Fiorentino, Italy, Fax. (+39)‐055‐457‐3531
| | - Stefano Menichetti
- Dipartimento di Chimica “U. Schiff”, Polo Scientifico e Tecnologico Università di Firenze, Via della Lastruccia, 3‐13, 50019 Sesto Fiorentino, Italy, Fax. (+39)‐055‐457‐3531
| |
Collapse
|
32
|
Amorati R, Valgimigli L. Modulation of the antioxidant activity of phenols by non-covalent interactions. Org Biomol Chem 2012; 10:4147-58. [DOI: 10.1039/c2ob25174d] [Citation(s) in RCA: 115] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
|
33
|
Sulfanyl stabilization of copper-bonded phenoxyls in model complexes and galactose oxidase. Proc Natl Acad Sci U S A 2011; 108:18600-5. [PMID: 22065750 DOI: 10.1073/pnas.1109931108] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Integrating sulfanyl substituents into copper-bonded phenoxyls significantly alters their optical and redox properties and provides insight into the influence of cysteine modification of the tyrosine cofactor in the enzyme galactose oxidase. The model complexes [1(SR2)](+) are class II mixed-valent Cu(II)-phenoxyl-phenolate species that exhibit intervalence charge transfer bands and intense visible sulfur-aryl π → π* transitions in the energy range, which provides a greater spectroscopic fidelity to oxidized galactose oxidase than non-sulfur-bearing analogs. The potentials for phenolate-based oxidations of the sulfanyl-substituted 1(SR2) are lower than the alkyl-substituted analogs by up to ca. 150 mV and decrease following the steric trend: -S(t)Bu > -S(i) Pr > -SMe. Density functional theory calculations suggest that reducing the steric demands of the sulfanyl substituent accommodates an in-plane conformation of the alkylsulfanyl group with the aromatic ring, which stabilizes the phenoxyl hole by ca. 8 kcal mol(-1) (1 kcal = 4.18 kJ; 350 mV) through delocalization onto the sulfur atom. Sulfur K-edge X-ray absorption spectroscopy clearly indicates a contribution of ca. 8-13% to the hole from the sulfur atoms in [1(SR2)](+). The electrochemical results for the model complexes corroborate the ca. 350 mV (density functional theory) contribution of hole delocalization on to the cysteine-tyrosine cross-link to the stability of the phenoxyl radical in the enzyme, while highlighting the importance of the in-plane conformation observed in all crystal structures of the enzyme.
Collapse
|
34
|
Viglianisi C, Bartolozzi MG, Pedulli GF, Amorati R, Menichetti S. Optimization of the Antioxidant Activity of Hydroxy-Substituted 4-Thiaflavanes: A Proof-of-Concept Study. Chemistry 2011; 17:12396-404. [DOI: 10.1002/chem.201101146] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2011] [Revised: 08/02/2011] [Indexed: 11/08/2022]
|
35
|
Chen J, Vannucci AK, Mebi CA, Okumura N, Borowski SC, Lockett LT, Swenson M, Lichtenberger DL, Evans DH, Glass RS. Catalysis of Electrochemical Reduction of Weak Acids to Produce H2: Role of O‒H…S Hydrogen Bonding. PHOSPHORUS SULFUR 2011. [DOI: 10.1080/10426507.2010.523035] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Jinzhu Chen
- a Department of Chemistry and Biochemistry , The University of Arizona , Tucson, Arizona, USA
| | - Aaron K. Vannucci
- a Department of Chemistry and Biochemistry , The University of Arizona , Tucson, Arizona, USA
| | - Charles A. Mebi
- a Department of Chemistry and Biochemistry , The University of Arizona , Tucson, Arizona, USA
| | - Noriko Okumura
- a Department of Chemistry and Biochemistry , The University of Arizona , Tucson, Arizona, USA
| | - Susan C. Borowski
- a Department of Chemistry and Biochemistry , The University of Arizona , Tucson, Arizona, USA
| | - L. Tori Lockett
- a Department of Chemistry and Biochemistry , The University of Arizona , Tucson, Arizona, USA
| | - Matthew Swenson
- a Department of Chemistry and Biochemistry , The University of Arizona , Tucson, Arizona, USA
| | - Dennis L. Lichtenberger
- a Department of Chemistry and Biochemistry , The University of Arizona , Tucson, Arizona, USA
| | - Dennis H. Evans
- a Department of Chemistry and Biochemistry , The University of Arizona , Tucson, Arizona, USA
| | - Richard S. Glass
- a Department of Chemistry and Biochemistry , The University of Arizona , Tucson, Arizona, USA
| |
Collapse
|
36
|
Amorati R, Attanasi OA, Favi G, Menichetti S, Pedulli GF, Viglianisi C. Amphiphilic antioxidants from “cashew nut shell liquid” (CNSL) waste. Org Biomol Chem 2011; 9:1352-5. [DOI: 10.1039/c0ob01040e] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
37
|
Johansson H, Shanks D, Engman L, Amorati R, Pedulli GF, Valgimigli L. Long-Lasting Antioxidant Protection: A Regenerable BHA Analogue. J Org Chem 2010; 75:7535-41. [DOI: 10.1021/jo101239c] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Henrik Johansson
- Department of Biochemistry and Organic Chemistry, Uppsala University, Box 576, SE-751 23 Uppsala, Sweden
| | - David Shanks
- Department of Biochemistry and Organic Chemistry, Uppsala University, Box 576, SE-751 23 Uppsala, Sweden
| | - Lars Engman
- Department of Biochemistry and Organic Chemistry, Uppsala University, Box 576, SE-751 23 Uppsala, Sweden
| | - Riccardo Amorati
- Department of Organic Chemistry “A. Mangini”, University of Bologna, via S. Giacomo 11, 40126 Bologna, Italy
| | - Gian Franco Pedulli
- Department of Organic Chemistry “A. Mangini”, University of Bologna, via S. Giacomo 11, 40126 Bologna, Italy
| | - Luca Valgimigli
- Department of Organic Chemistry “A. Mangini”, University of Bologna, via S. Giacomo 11, 40126 Bologna, Italy
| |
Collapse
|
38
|
Lucarini M, Pedulli GF. Free radical intermediates in the inhibition of the autoxidation reaction. Chem Soc Rev 2010; 39:2106-19. [PMID: 20514720 DOI: 10.1039/b901838g] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The autoxidation of organic materials is a detrimental radical chain process often leading to their rapid deterioration unless they are protected by preventive and/or chain breaking antioxidants. The properties of the more important family of the latter ones, that one of phenols, are illustrated in this tutorial review. A short outline of diarylamine antioxidants is also given. We describe simple experimental methods employed for the determination of the two parameters more useful for estimating the inhibiting power of antioxidants, that is the kinetic rate constant for their reaction with the chain carrying peroxyl radicals, k(inh), to give persistent phenoxyl or aminyl radicals and the bond dissociation enthalpy BDE(X-H) (X = O, N) of the bond cleaved in the inhibition process. The dependence of these parameters on the number and nature of the substituents is discussed and, in the case of phenols, a simple rule allowing to predict with reasonable accuracy the BDE and k(inh) values, from their structure. The effect of solvent polarity on the antioxidant power is also described. Finally, the information on the mechanism of reaction between phenols and peroxyl radicals provided by both experiments and theoretical calculations are examined. Because of difficulties associated with the analysis of non-homogenous systems all the reported results refer to homogenous solution in which experimental data can be analysed by means of more reliable and complete treatments.
Collapse
Affiliation(s)
- Marco Lucarini
- Dipartimento di Chimica Organica A. Mangini, Università di Bologna, Via San Giacomo 11, 40126, Italy
| | | |
Collapse
|
39
|
Bartesaghi S, Wenzel J, Trujillo M, López M, Joseph J, Kalyanaraman B, Radi R. Lipid peroxyl radicals mediate tyrosine dimerization and nitration in membranes. Chem Res Toxicol 2010; 23:821-35. [PMID: 20170094 DOI: 10.1021/tx900446r] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Protein tyrosine dimerization and nitration by biologically relevant oxidants usually depend on the intermediate formation of tyrosyl radical ((*)Tyr). In the case of tyrosine oxidation in proteins associated with hydrophobic biocompartments, the participation of unsaturated fatty acids in the process must be considered since they typically constitute preferential targets for the initial oxidative attack. Thus, we postulate that lipid-derived radicals mediate the one-electron oxidation of tyrosine to (*)Tyr, which can afterward react with another (*)Tyr or with nitrogen dioxide ((*)NO(2)) to yield 3,3'-dityrosine or 3-nitrotyrosine within the hydrophobic structure, respectively. To test this hypothesis, we have studied tyrosine oxidation in saturated and unsaturated fatty acid-containing phosphatidylcholine (PC) liposomes with an incorporated hydrophobic tyrosine analogue BTBE (N-t-BOC l-tyrosine tert-butyl ester) and its relationship with lipid peroxidation promoted by three oxidation systems, namely, peroxynitrite, hemin, and 2,2'-azobis (2-amidinopropane) hydrochloride. In all cases, significant tyrosine (BTBE) oxidation was seen in unsaturated PC liposomes, in a way that was largely decreased at low oxygen concentrations. Tyrosine oxidation levels paralleled those of lipid peroxidation (i.e., malondialdehyde and lipid hydroperoxides), lipid-derived radicals and BTBE phenoxyl radicals were simultaneously detected by electron spin resonance spin trapping, supporting an association between the two processes. Indeed, alpha-tocopherol, a known reactant with lipid peroxyl radicals (LOO(*)), inhibited both tyrosine oxidation and lipid peroxidation induced by all three oxidation systems. Moreover, oxidant-stimulated liposomal oxygen consumption was dose dependently inhibited by BTBE but not by its phenylalanine analogue, BPBE (N-t-BOC l-phenylalanine tert-butyl ester), providing direct evidence for the reaction between LOO(*) and the phenol moiety in BTBE, with an estimated second-order rate constant of 4.8 x 10(3) M(-1) s(-1). In summary, the data presented herein demonstrate that LOO(*) mediates tyrosine oxidation processes in hydrophobic biocompartments and provide a new mechanistic insight to understand protein oxidation and nitration in lipoproteins and biomembranes.
Collapse
Affiliation(s)
- Silvina Bartesaghi
- Departamento de Histología y Embriología, Facultad de Medicina, Universidad de la República, Avda. General Flores 2125, 11800 Montevideo, Uruguay
| | | | | | | | | | | | | |
Collapse
|
40
|
Lee YK, Whittaker MM, Whittaker JW. The electronic structure of the Cys-Tyr(*) free radical in galactose oxidase determined by EPR spectroscopy. Biochemistry 2010; 47:6637-49. [PMID: 18512952 DOI: 10.1021/bi800305d] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Galactose oxidase is a metalloenzyme containing a novel metalloradical complex in its active site, comprised of a mononuclear copper ion associated with a protein free radical. The free radical has been shown to be localized on an intrinsic redox cofactor, 3'-(S-cysteinyl)tyrosine (Cys-Tyr), formed by a posttranslational covalent coupling of tyrosine and cysteine side chains in a self-processing reaction. The role of the thioether linkage in the function of the Cys-Tyr cofactor is unresolved, and some computational studies have suggested that the thioether substituent has a negligible effect on the properties of the tyrosyl free radical. In order to address this question experimentally, we have incorporated site-selectively labeled tyrosine ((2)H, (13)C, (17)O) into galactose oxidase using an engineered tyrosine auxotroph strain of Pichia pastoris . (33)S was also incorporated into the protein. EPR spectra for the Cys-Tyr(*) free radical in each of these isotopic variants were analyzed to extract nuclear hyperfine parameters for comparison with theoretical predictions, and the unpaired spin distribution in the free radical was reconstructed from the hyperfine data. These labeling studies allow the first comprehensive experimental evaluation of the effect of the thioether linkage on the properties of Cys-Tyr(*) and indicate that previous calculations significantly underestimated the contribution of this feature to the electronic ground state of the free radical.
Collapse
Affiliation(s)
- Yuk-Ki Lee
- Department of Environmental and Biomolecular Systems, OGI School of Science and Engineering, Oregon Health and Science University, 20000 Northwest Walker Road, Beaverton, Oregon 97006-8921, USA
| | | | | |
Collapse
|
41
|
Amorati R, Pedulli GF, Valgimigli L, Johansson H, Engman L. Organochalcogen Substituents in Phenolic Antioxidants. Org Lett 2010; 12:2326-9. [DOI: 10.1021/ol100683u] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Riccardo Amorati
- Department of Organic Chemistry “A. Mangini”, University of Bologna, Via S. Giacomo 11, I-40126 Bologna, Italy, and Department of Biochemistry and Organic Chemistry, Uppsala University, Box 576, SE-751 23 Uppsala, Sweden
| | - Gian Franco Pedulli
- Department of Organic Chemistry “A. Mangini”, University of Bologna, Via S. Giacomo 11, I-40126 Bologna, Italy, and Department of Biochemistry and Organic Chemistry, Uppsala University, Box 576, SE-751 23 Uppsala, Sweden
| | - Luca Valgimigli
- Department of Organic Chemistry “A. Mangini”, University of Bologna, Via S. Giacomo 11, I-40126 Bologna, Italy, and Department of Biochemistry and Organic Chemistry, Uppsala University, Box 576, SE-751 23 Uppsala, Sweden
| | - Henrik Johansson
- Department of Organic Chemistry “A. Mangini”, University of Bologna, Via S. Giacomo 11, I-40126 Bologna, Italy, and Department of Biochemistry and Organic Chemistry, Uppsala University, Box 576, SE-751 23 Uppsala, Sweden
| | - Lars Engman
- Department of Organic Chemistry “A. Mangini”, University of Bologna, Via S. Giacomo 11, I-40126 Bologna, Italy, and Department of Biochemistry and Organic Chemistry, Uppsala University, Box 576, SE-751 23 Uppsala, Sweden
| |
Collapse
|
42
|
Menichetti S, Amorati R, Bartolozzi MG, Pedulli GF, Salvini A, Viglianisi C. A Straightforward Hetero-Diels-Alder Approach to (2-ambo,4′R,8′R)-α/β/γ/δ-4-Thiatocopherol. European J Org Chem 2010. [DOI: 10.1002/ejoc.200901493] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
|
43
|
Yu A, Wang J, Xue X, Wang Y. Theoretical study of the peripheral disulfide bridge substituent effects on the antioxidant properties of naphthyridine diol derivatives. J Phys Chem A 2010; 114:1008-16. [PMID: 20000581 DOI: 10.1021/jp908658z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The effect of a peripheral disulfide bridge substituent on the phenolic O-H bond dissociation energy (BDE) and the ionization potential (IP) of naphthyridine diol has been studied by density functional theory (DFT) calculation. Compared with naphthalene diol, the substituent of a peripheral disulfide bridge group is very efficient in reducing the BDE, whereas the insertion of nitrogen atoms into the naphthalenic ring only slightly changes the BDE of O-H bond but dramatically enhances the IP. It is similar with the stereoelectronic effect of the heterocyclic ring for the well-known alpha-tocopherol antioxidant and leads to a highly delocalized spin distribution. With the incorporation of these two aspects, a potential antioxidant is expected to be more active and more stable than alpha-tocopherol.
Collapse
Affiliation(s)
- Ao Yu
- Central Laboratory, College of Chemistry, Nankai University, Tianjin 300071, People's Republic of China.
| | | | | | | |
Collapse
|
44
|
Menichetti S, Viglianisi C. Generation and Trapping of o-Thioquinones on Solid Support: Synthesis of Hydroxylated 4-Thiaflavans. PHOSPHORUS SULFUR 2009. [DOI: 10.1080/10426500902856339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Stefano Menichetti
- a Dipartimento di Chimica Organica and Laboratorio di Progettazione Sintesi e Studio di Eterocicli Biologicamente Attivi (HeteroBioLab), Polo Scientifico e Tecnologico , Università di Firenze , Sesto Fiorentino, Italy
| | - Caterina Viglianisi
- a Dipartimento di Chimica Organica and Laboratorio di Progettazione Sintesi e Studio di Eterocicli Biologicamente Attivi (HeteroBioLab), Polo Scientifico e Tecnologico , Università di Firenze , Sesto Fiorentino, Italy
| |
Collapse
|
45
|
Litwinienko G, DiLabio GA, Mulder P, Korth HG, Ingold KU. Intramolecular and Intermolecular Hydrogen Bond Formation by Some Ortho-Substituted Phenols: Some Surprising Results from an Experimental and Theoretical Investigation. J Phys Chem A 2009; 113:6275-88. [DOI: 10.1021/jp900876q] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Grzegorz Litwinienko
- Department of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland, National Institute for Nanotechnology, National Research Council of Canada, 11421 Saskatchewan Drive, Edmonton, Alberta, Canada T6G 2M9, Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands, Institut für Organische Chemie, Universität Duisburg-Essen, D-45117 Essen, Germany, and Steacie Institute for Molecular Sciences, National Research Council of Canada, 100 Sussex Drive, Ottawa,
| | - Gino A. DiLabio
- Department of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland, National Institute for Nanotechnology, National Research Council of Canada, 11421 Saskatchewan Drive, Edmonton, Alberta, Canada T6G 2M9, Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands, Institut für Organische Chemie, Universität Duisburg-Essen, D-45117 Essen, Germany, and Steacie Institute for Molecular Sciences, National Research Council of Canada, 100 Sussex Drive, Ottawa,
| | - Peter Mulder
- Department of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland, National Institute for Nanotechnology, National Research Council of Canada, 11421 Saskatchewan Drive, Edmonton, Alberta, Canada T6G 2M9, Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands, Institut für Organische Chemie, Universität Duisburg-Essen, D-45117 Essen, Germany, and Steacie Institute for Molecular Sciences, National Research Council of Canada, 100 Sussex Drive, Ottawa,
| | - Hans-Gert Korth
- Department of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland, National Institute for Nanotechnology, National Research Council of Canada, 11421 Saskatchewan Drive, Edmonton, Alberta, Canada T6G 2M9, Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands, Institut für Organische Chemie, Universität Duisburg-Essen, D-45117 Essen, Germany, and Steacie Institute for Molecular Sciences, National Research Council of Canada, 100 Sussex Drive, Ottawa,
| | - K. U. Ingold
- Department of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland, National Institute for Nanotechnology, National Research Council of Canada, 11421 Saskatchewan Drive, Edmonton, Alberta, Canada T6G 2M9, Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands, Institut für Organische Chemie, Universität Duisburg-Essen, D-45117 Essen, Germany, and Steacie Institute for Molecular Sciences, National Research Council of Canada, 100 Sussex Drive, Ottawa,
| |
Collapse
|
46
|
Amorati R, Menichetti S, Mileo E, Pedulli G, Viglianisi C. Hydrogen-Atom Transfer Reactions fromortho-Alkoxy-Substituted Phenols: An Experimental Approach. Chemistry 2009; 15:4402-10. [DOI: 10.1002/chem.200802454] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
47
|
Lucas HR, Karlin KD. Copper-Carbon Bonds in Mechanistic and Structural Probing of Proteins as well as in Situations where Copper is a Catalytic or Receptor Site. METAL-CARBON BONDS IN ENZYMES AND COFACTORS 2009. [DOI: 10.1039/9781847559333-00295] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
While copper-carbon bonds are well appreciated in organometallic synthetic chemistry, such occurrences are less known in biological settings. By far, the greatest incidence of copper-carbon moieties is in bioinorganic research aimed at probing copper protein active site structure and mechanism; for example, carbon monoxide (CO) binding as a surrogate for O2. Using infrared (IR) spectroscopy, CO coordination to cuprous sites has proven to be an extremely useful tool for determining active site copper ligation (e.g., donor atom number and type). The coupled (hemocyanin, tyrosinase, catechol oxidase) and non-coupled (peptidylglycine α-hydroxylating monooxygenase, dopamine β-monooxygenase) binuclear copper proteins as well as the heme-copper oxidases (HCOs) have been studied extensively via this method. In addition, environmental changes within the vicinity of the active site have been determined based on shifts in the CO stretching frequencies, such as for copper amine oxidases, nitrite reductases and again in the binuclear proteins and HCOs. In many situations, spectroscopic monitoring has provided kinetic and thermodynamic data on CuI-CO formation and CO dissociation from copper(I); recently, processes occurring on a femtosecond timescale have been reported. Copper-cyano moieties have also been useful for obtaining insights into the active site structure and mechanisms of copper-zinc superoxide dismutase, azurin, nitrous oxide reductase, and multi-copper oxidases. Cyanide is a good ligand for both copper(I) and copper(II), therefore multiple physical-spectroscopic techniques can be applied. A more obvious occurrence of a “Cu-C” moiety was recently described for a CO dehydrogenase which contains a novel molybdenum-copper catalytic site. A bacterial copper chaperone (CusF) was recently established to have a novel d-π interaction comprised of copper(I) with the arene containing side-chain of a tryptophan amino acid residue. Meanwhile, good evidence exists that a plant receptor site (ETR1) utilizes copper(I) to sense ethylene, a growth hormone. A copper olfactory receptor has also been suggested. All of the above mentioned occurrences or uses of carbon-containing substrates and/or probes are reviewed and discussed within the framework of copper proteins and other relevant systems.
Collapse
Affiliation(s)
- Heather R. Lucas
- Department of Chemistry, The Johns Hopkins University 3400 N. Charles Street Baltimore MD 21218 USA
| | - Kenneth D. Karlin
- Department of Chemistry, The Johns Hopkins University 3400 N. Charles Street Baltimore MD 21218 USA
| |
Collapse
|
48
|
Mozziconacci O, Williams TD, Kerwin BA, Schöneich C. Reversible Intramolecular Hydrogen Transfer between Protein Cysteine Thiyl Radicals and αC−H Bonds in Insulin: Control of Selectivity by Secondary Structure. J Phys Chem B 2008; 112:15921-32. [DOI: 10.1021/jp8066519] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Olivier Mozziconacci
- Department of Pharmaceutical Chemistry, 2095 Constant Avenue, University of Kansas, Lawrence, Kansas 66047; Mass Spectrometry Laboratory, University of Kansas, Lawrence, Kansas 66045; and the Department of Process and Product Development, Amgen Inc., Seattle, Washington 98119
| | - Todd D. Williams
- Department of Pharmaceutical Chemistry, 2095 Constant Avenue, University of Kansas, Lawrence, Kansas 66047; Mass Spectrometry Laboratory, University of Kansas, Lawrence, Kansas 66045; and the Department of Process and Product Development, Amgen Inc., Seattle, Washington 98119
| | - Bruce A. Kerwin
- Department of Pharmaceutical Chemistry, 2095 Constant Avenue, University of Kansas, Lawrence, Kansas 66047; Mass Spectrometry Laboratory, University of Kansas, Lawrence, Kansas 66045; and the Department of Process and Product Development, Amgen Inc., Seattle, Washington 98119
| | - Christian Schöneich
- Department of Pharmaceutical Chemistry, 2095 Constant Avenue, University of Kansas, Lawrence, Kansas 66047; Mass Spectrometry Laboratory, University of Kansas, Lawrence, Kansas 66045; and the Department of Process and Product Development, Amgen Inc., Seattle, Washington 98119
| |
Collapse
|
49
|
Buzzini P, Menichetti S, Pagliuca C, Viglianisi C, Branda E, Turchetti B. Antimycotic activity of 4-thioisosteres of flavonoids towards yeast and yeast-like microorganisms. Bioorg Med Chem Lett 2008; 18:3731-3. [DOI: 10.1016/j.bmcl.2008.05.048] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2008] [Revised: 05/12/2008] [Accepted: 05/14/2008] [Indexed: 11/30/2022]
|
50
|
|