1
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He Y, Fan Z, Sun P, Jiang H, Chen Z, Tang G, Hou Z, Sun Y, Yi Y, Shi W, Ge D. Mechanism of Self-Oxidative Copolymerization and its Application with Polydopamine-pyrrole Nano-copolymers. SMALL METHODS 2024; 8:e2301405. [PMID: 38168901 DOI: 10.1002/smtd.202301405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 12/11/2023] [Indexed: 01/05/2024]
Abstract
Currently, the copolymer of dopamine (DA) and pyrrole (PY) via chemical and electrochemical oxidation usually requires additional oxidants, and lacks flexibility in regulating the size and morphology, thereby limiting the broad applications of DA-PY copolymer in biomedicine. Herein, the semiquinone radicals produced by the self-oxidation of DA is ingeniously utilized as the oxidant to initiate the following copolymerization with PY, and a series of quinone-rich polydopamine-pyrrole copolymers (PDAm-nPY) with significantly enhanced absorption in near-infrared (NIR) region without any additional oxidant assistance is obtained. Moreover, the morphology and size of PDAm-nPY can be regulated by changing the concentration of DA and PY, thereby optimizing nanoscale PDA0.05-0.15PY particles (≈ 150 nm) with excellent NIR absorption and surface modification activity are successfully synthesized. Such PDA0.05-0.15PY particles show effective photoacoustic (PA) imaging and photothermal therapy (PTT) against 4T1 tumors in vivo. Furthermore, other catechol derivatives can also copolymerize with PY under the same conditions. This work by fully utilizing the semiquinone radical active intermediates produced through the self-oxidation of DA reduces the dependence on external oxidants in the synthesis of composite materials and predigests the preparation procedure, which provides a novel, simple, and green strategy for the synthesis of other newly catechol-based functional copolymers.
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Affiliation(s)
- Yuan He
- The Higher Educational Key Laboratory for Biomedical Engineering of Fujian Province/Research Center of Biomedical Engineering of Xiamen, Department of Biomaterials, College of Materials, Xiamen University, Xiamen, Fujian, 361005, China
- Department of Cardiothoracic Surgery, The 909th Hospital, School of Medicine, Xiamen University, Zhangzhou, Fujian, 363000, China
| | - Zhongxiong Fan
- Institute of Materia Medica & College of Life Science and Technology, Xinjiang University, Urumqi, Xinjiang, 830017, China
| | - Pengfei Sun
- Department of Chemistry, College of Chemistry and Chemical Engineering, and the Key Laboratory for Chemical Biology of Fujian Province, Xiamen University, Xiamen, Fujian, 361005, China
| | - Hairong Jiang
- Department of Chemistry, College of Chemistry and Chemical Engineering, and the Key Laboratory for Chemical Biology of Fujian Province, Xiamen University, Xiamen, Fujian, 361005, China
| | - Zhou Chen
- The Higher Educational Key Laboratory for Biomedical Engineering of Fujian Province/Research Center of Biomedical Engineering of Xiamen, Department of Biomaterials, College of Materials, Xiamen University, Xiamen, Fujian, 361005, China
| | - Guo Tang
- Department of Chemistry, College of Chemistry and Chemical Engineering, and the Key Laboratory for Chemical Biology of Fujian Province, Xiamen University, Xiamen, Fujian, 361005, China
| | - Zhenqing Hou
- The Higher Educational Key Laboratory for Biomedical Engineering of Fujian Province/Research Center of Biomedical Engineering of Xiamen, Department of Biomaterials, College of Materials, Xiamen University, Xiamen, Fujian, 361005, China
| | - Yanan Sun
- The Higher Educational Key Laboratory for Biomedical Engineering of Fujian Province/Research Center of Biomedical Engineering of Xiamen, Department of Biomaterials, College of Materials, Xiamen University, Xiamen, Fujian, 361005, China
| | - Yunfeng Yi
- Department of Cardiothoracic Surgery, The 909th Hospital, School of Medicine, Xiamen University, Zhangzhou, Fujian, 363000, China
| | - Wei Shi
- The Higher Educational Key Laboratory for Biomedical Engineering of Fujian Province/Research Center of Biomedical Engineering of Xiamen, Department of Biomaterials, College of Materials, Xiamen University, Xiamen, Fujian, 361005, China
| | - Dongtao Ge
- The Higher Educational Key Laboratory for Biomedical Engineering of Fujian Province/Research Center of Biomedical Engineering of Xiamen, Department of Biomaterials, College of Materials, Xiamen University, Xiamen, Fujian, 361005, China
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2
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Gabbanini S, Neba JN, Matera R, Valgimigli L. Photochemical and Oxidative Degradation of Chamazulene Contained in Artemisia, Matricaria and Achillea Essential Oils and Setup of Protection Strategies. Molecules 2024; 29:2604. [PMID: 38893479 PMCID: PMC11173868 DOI: 10.3390/molecules29112604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2024] [Revised: 05/23/2024] [Accepted: 05/25/2024] [Indexed: 06/21/2024] Open
Abstract
Chamazulene (CA) is an intensely blue molecule with a wealth of biological properties. In cosmetics, chamazulene is exploited as a natural coloring and soothing agent. CA is unstable and tends to spontaneously degrade, accelerated by light. We studied the photodegradation of CA upon controlled exposure to UVB-UVA irradiation by multiple techniques, including GC-MS, UHPLC-PDA-ESI-MS/MS and by direct infusion in ESI-MSn, which were matched to in silico mass spectral simulations to identify degradation products. Seven byproducts formed upon UVA exposure for 3 h at 70 mW/cm2 (blue-to-green color change) were identified, including CA dimers and CA benzenoid, which were not found on extended 6 h irradiation (green-to-yellow fading). Photostability tests with reduced irradiance conducted in various solvents in the presence/absence of air indicated highest degradation in acetonitrile in the presence of oxygen, suggesting a photo-oxidative mechanism. Testing in the presence of antioxidants (tocopherol, ascorbyl palmitate, hydroxytyrosol, bakuchiol, γ-terpinene, TEMPO and their combinations) indicated the highest protection by tocopherol and TEMPO. Sunscreens ethylhexyl methoxycinnamate and particularly Tinosorb® S (but not octocrylene) showed good CA photoprotection. Thermal stability tests indicated no degradation of CA in acetonitrile at 50 °C in the dark for 50 days; however, accelerated degradation occurred in the presence of ascorbyl palmitate.
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Affiliation(s)
- Simone Gabbanini
- R&D Department, BeC s.r.l., Via C. Monteverdi 49, 47122 Forlì, Italy;
| | - Jerome Ngwa Neba
- Department of Chemistry “Ciamician”, University of Bologna, Via Gobetti 85, 40129 Bologna, Italy;
| | - Riccardo Matera
- R&D Department, BeC s.r.l., Via C. Monteverdi 49, 47122 Forlì, Italy;
| | - Luca Valgimigli
- Department of Chemistry “Ciamician”, University of Bologna, Via Gobetti 85, 40129 Bologna, Italy;
- Tecnopolo di Rimini, Via D. Campana 71, 47922 Rimini, Italy
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3
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Kaur R, Gupta TB, Bronlund J, Singh J, Kaur L. Synthesis and characterisation of Mānuka and rosemary oil-based nano-entities and their application in meat. Food Chem 2024; 436:137600. [PMID: 37837683 DOI: 10.1016/j.foodchem.2023.137600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 08/30/2023] [Accepted: 09/24/2023] [Indexed: 10/16/2023]
Abstract
Mānuka (MO) and rosemary oils (RO) -containing nanoemulsions and nanocapsules made of sodium alginate and whey protein, were designed and compared for their antioxidant effect. Mānuka oil-nanoemulsions and nanocapsules had smaller particle sizes (343 and 330 nm), less negative zeta potential (-12 mV and -10 mV), higher phenolic content, and antiradical characteristics than RO-nano-entities. However, nano-entities of both oils showed more thermostability and sustained release than free oils. Further, the antioxidant effect of essential oils and their nano-entities was compared against sodium nitrite (SN)-added and without antioxidants-added (controls) and Wagyu and crossbred beef pastes (14 days refrigerated storage). No significant difference among MO, RO and their nano-entities was noticed in crossbred pastes, while in Wagyu, nanoemulsions showed the lowest oxidation values than controls and SN-added pastes. Hence, nano-entities can be alternatives to chemical preservatives as natural antioxidants in meat preservation, along with improved thermal stability and release than free oils.
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Affiliation(s)
- Ramandeep Kaur
- School of Food and Advanced Technology, Massey University, 4442 Palmerston North, New Zealand; Riddet Institute, Massey University, 4442 Palmerston North, New Zealand
| | - Tanushree B Gupta
- Food System Integrity Team, AgResearch Ltd., Hopkirk Research Institute, Massey University, Palmerston North 4472, New Zealand
| | - John Bronlund
- School of Food and Advanced Technology, Massey University, 4442 Palmerston North, New Zealand; Riddet Institute, Massey University, 4442 Palmerston North, New Zealand
| | - Jaspreet Singh
- School of Food and Advanced Technology, Massey University, 4442 Palmerston North, New Zealand; Riddet Institute, Massey University, 4442 Palmerston North, New Zealand
| | - Lovedeep Kaur
- School of Food and Advanced Technology, Massey University, 4442 Palmerston North, New Zealand; Riddet Institute, Massey University, 4442 Palmerston North, New Zealand.
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4
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Asma U, Bertotti ML, Zamai S, Arnold M, Amorati R, Scampicchio M. A Kinetic Approach to Oxygen Radical Absorbance Capacity (ORAC): Restoring Order to the Antioxidant Activity of Hydroxycinnamic Acids and Fruit Juices. Antioxidants (Basel) 2024; 13:222. [PMID: 38397820 PMCID: PMC10886186 DOI: 10.3390/antiox13020222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 01/26/2024] [Accepted: 02/02/2024] [Indexed: 02/25/2024] Open
Abstract
This study introduces a kinetic model that significantly improves the interpretation of the oxygen radical absorbance capacity (ORAC) assay. Our model accurately simulates and fits the bleaching kinetics of fluorescein in the presence of various antioxidants, achieving high correlation values (R2 > 0.99) with the experimental data. The fit to the experimental data is achieved by optimizing two rate constants, k5 and k6. The k5 value reflects the reactivity of antioxidants toward scavenging peroxyl radicals, whereas k6 measures the ability of antioxidants to regenerate oxidized fluorescein. These parameters (1) allow the detailed classification of cinnamic acids based on their structure-activity relationships, (2) provide insights into the interaction of alkoxyl radicals with fluorescein, and (3) account for the regeneration of fluorescein radicals by antioxidants. The application of the model to different antioxidants and fruit extracts reveals significant deviations from the results of traditional ORAC tests based on the area under the curve (AUC) approach. For example, lemon juice, rich in 'fast' antioxidants such as ascorbic acid, shows a high k5 value, in contrast to its low AUC values. This finding underscores the limitations of the AUC approach and highlights the advantages of our kinetic model in understanding antioxidative dynamics in food systems. This study presents a comprehensive, quantitative, mechanism-oriented approach to assessing antioxidant reactivity, demonstrating a significant improvement in ORAC assay applications.
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Affiliation(s)
- Umme Asma
- Faculty of Agricultural, Environment and Food Sciences, Free University of Bozen-Bolzano, Piazza Università 1, 39100 Bolzano, Italy; (U.A.); (S.Z.)
| | - Maria Letizia Bertotti
- Faculty of Engineering, Free University of Bozen-Bolzano, Piazza Università 1, 39100 Bolzano, Italy;
| | - Simone Zamai
- Faculty of Agricultural, Environment and Food Sciences, Free University of Bozen-Bolzano, Piazza Università 1, 39100 Bolzano, Italy; (U.A.); (S.Z.)
| | - Marcellus Arnold
- Department of Gastronomy Science and Functional Foods, Faculty of Food Science and Nutrition, Poznań University of Life Sciences, Wojska Polskiego 31, 60624 Poznań, Poland;
| | - Riccardo Amorati
- Department of Chemistry “G. Ciamician”, University of Bologna, Via Gobetti 83, 40129 Bologna, Italy;
| | - Matteo Scampicchio
- Faculty of Agricultural, Environment and Food Sciences, Free University of Bozen-Bolzano, Piazza Università 1, 39100 Bolzano, Italy; (U.A.); (S.Z.)
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5
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Suhag R, Ferrentino G, Morozova K, Zatelli D, Scampicchio M, Amorati R. Antioxidant efficiency and oxidizability of mayonnaise by oximetry and isothermal calorimetry. Food Chem 2024; 433:137274. [PMID: 37666126 DOI: 10.1016/j.foodchem.2023.137274] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 08/21/2023] [Accepted: 08/22/2023] [Indexed: 09/06/2023]
Abstract
This study aimed to introduce a new method based on isothermal calorimetry (IC) for measuring the autoxidation rate in mayonnaise samples. Mayonnaise samples were prepared by homogenizing an aqueous phase, consisting of vinegar and egg yolk, with various oil phases, including sunflower, corn, extra virgin olive, grape seed, and apple seed oils at 60 °C. The rate of free radical formation (Ri) was controlled by adding AIBN (Ri = 4.4±0.1×10-9 M/s). The autoxidation rate determined by IC was highly correlated with the one measured using the oxygen uptake method (R2 = 0.99). The IC method accurately indicated the antioxidant capacity and rates of both inhibited and uninhibited periods, together with the oxidizability of mayonnaise samples. The mayonnaise made with extra virgin olive oil exhibited the lowest oxidizability, while sunflower oil showed maximum antioxidant efficiency. A significant advantage of the IC method was its ability to simultaneously measure up to 24 samples with minimal effort.
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Affiliation(s)
- Rajat Suhag
- Faculty of Agricultural, Environmental and Food Sciences, Free University of Bolzano, Piazza Università, 1, Bolzano 39100, Italy
| | - Giovanna Ferrentino
- Faculty of Agricultural, Environmental and Food Sciences, Free University of Bolzano, Piazza Università, 1, Bolzano 39100, Italy
| | - Ksenia Morozova
- Faculty of Agricultural, Environmental and Food Sciences, Free University of Bolzano, Piazza Università, 1, Bolzano 39100, Italy
| | | | - Matteo Scampicchio
- Faculty of Agricultural, Environmental and Food Sciences, Free University of Bolzano, Piazza Università, 1, Bolzano 39100, Italy.
| | - Riccardo Amorati
- Department of Chemistry "G. Ciamician", University of Bologna, Via S. Giacomo 11, Bologna I-40126, Italy
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Pan W, Giovanardi I, Sagynova T, Cariola A, Bresciani V, Masetti M, Valgimigli L. Potent Antioxidant and Anti-Tyrosinase Activity of Butein and Homobutein Probed by Molecular Kinetic and Mechanistic Studies. Antioxidants (Basel) 2023; 12:1763. [PMID: 37760066 PMCID: PMC10525132 DOI: 10.3390/antiox12091763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 09/06/2023] [Accepted: 09/11/2023] [Indexed: 09/29/2023] Open
Abstract
Butein (BU) and homobutein (HB) are bioactive polyhydroxylated chalcones widespread in dietary plants, whose antioxidant properties require mechanistic definition. They were investigated by inhibited autoxidation kinetic studies of methyl linoleate in Triton™ X-100 micelles at pH 7.4, 37 °C. Butein had kinh = (3.0 ± 0.9) × 104 M-1s-1 showing a chain-breaking mechanism with higher antioxidant activity than reference α-tocopherol (kinh = (2.2 ± 0.6) × 104 M-1s-1), particularly concerning the stoichiometry or peroxyl radical trapping n = 3.7 ± 1.1 vs. 2.0 for tocopherol. Homobutein had kinh = (2.8 ± 0.9) × 103 M-1s-1, pairing the relative BDEOH measured by radical equilibration EPR as 78.4 ± 0.2 kcal/mol for BU and estimated as 82.6 kcal/mol for HB. The inhibition of mushroom tyrosinase (mTYR) by HB and BU was also investigated. BU gives a reversible uncompetitive inhibition of monophenolase reaction with KI' = 9.95 ± 2.69 µM and mixed-type diphenolase inhibition with KI = 3.30 ± 0.75 µM and KI' = 18.75 ± 5.15 µM, while HB was nearly competitive toward both mono- and diphenolase with respective KI of 2.76 ± 0.70 µM and 2.50 ± 1.56 µM. IC50 values (monophenolase/diphenolase at 1 mM substrate) were 10.88 ± 2.19 µM/15.20 ± 1.25 µM, 14.78 ± 1.05 µM/12.36 ± 2.00 µM, and 33.14 ± 5.03 µM/18.27 ± 3.42 µM, respectively, for BU, HB, and reference kojic acid. Molecular docking studies confirmed the mechanism. Results indicate very potent antioxidant activity for BU and potent anti-tyrosinase activity for both chalcones, which is discussed in relation to bioactivity toward protection from skin disorders and food oxidative spoilage.
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Affiliation(s)
- Wenkai Pan
- Department of Chemistry “G. Ciamician”, University of Bologna, Via P. Gobetti 85, 40129 Bologna, Italy
| | - Ilaria Giovanardi
- Department of Chemistry “G. Ciamician”, University of Bologna, Via P. Gobetti 85, 40129 Bologna, Italy
- Tecnopolo di Rimini, Via Dario Campana 71, 47922 Rimini, Italy
| | - Tomiris Sagynova
- Department of Chemistry “G. Ciamician”, University of Bologna, Via P. Gobetti 85, 40129 Bologna, Italy
- Tecnopolo di Rimini, Via Dario Campana 71, 47922 Rimini, Italy
| | - Alice Cariola
- Department of Chemistry “G. Ciamician”, University of Bologna, Via P. Gobetti 85, 40129 Bologna, Italy
- Tecnopolo di Rimini, Via Dario Campana 71, 47922 Rimini, Italy
| | - Veronica Bresciani
- Department of Pharmacy and Biotechnology, University of Bologna, Via Belmeloro 6, 40126 Bologna, Italy
- Computational and Chemical Biology, Italian Institute of Technology, Via Enrico Melen 83, 16152 Genova, Italy
| | - Matteo Masetti
- Department of Pharmacy and Biotechnology, University of Bologna, Via Belmeloro 6, 40126 Bologna, Italy
| | - Luca Valgimigli
- Department of Chemistry “G. Ciamician”, University of Bologna, Via P. Gobetti 85, 40129 Bologna, Italy
- Tecnopolo di Rimini, Via Dario Campana 71, 47922 Rimini, Italy
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7
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Valgimigli L. Lipid Peroxidation and Antioxidant Protection. Biomolecules 2023; 13:1291. [PMID: 37759691 PMCID: PMC10526874 DOI: 10.3390/biom13091291] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 08/17/2023] [Accepted: 08/21/2023] [Indexed: 09/29/2023] Open
Abstract
Lipid peroxidation (LP) is the most important type of oxidative-radical damage in biological systems, owing to its interplay with ferroptosis and to its role in secondary damage to other biomolecules, such as proteins. The chemistry of LP and its biological consequences are reviewed with focus on the kinetics of the various processes, which helps understand the mechanisms and efficacy of antioxidant strategies. The main types of antioxidants are discussed in terms of structure-activity rationalization, with focus on mechanism and kinetics, as well as on their potential role in modulating ferroptosis. Phenols, pyri(mi)dinols, antioxidants based on heavy chalcogens (Se and Te), diarylamines, ascorbate and others are addressed, along with the latest unconventional antioxidant strategies based on the double-sided role of the superoxide/hydroperoxyl radical system.
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Affiliation(s)
- Luca Valgimigli
- Department of Chemistry "G. Ciamician", University of Bologna, Via Piero Gobetti 85, 40129 Bologna, Italy
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8
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Mavridi-Printezi A, Mollica F, Lucernati R, Montalti M, Amorati R. Insight into the Antioxidant Activity of 1,8-Dihydroxynaphthalene Allomelanin Nanoparticles. Antioxidants (Basel) 2023; 12:1511. [PMID: 37627506 PMCID: PMC10451768 DOI: 10.3390/antiox12081511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 07/21/2023] [Accepted: 07/25/2023] [Indexed: 08/27/2023] Open
Abstract
Melanins are stable and non-toxic pigments with great potential as chemopreventive agents against oxidative stress for medical and cosmetic applications. Allomelanin is a class of nitrogen-free melanin often found in fungi. The artificial allomelanin obtained by the polymerization of 1,8-dihydroxynaphthalene (DHN), poly-DHN (PDHN), has been recently indicated as a better radical quencher than polydopamine (PDA), a melanin model obtained by the polymerization of dopamine (DA); however, the chemical mechanisms underlying this difference are unclear. Here we investigate, by experimental and theoretical methods, the ability of PDHN nanoparticles (PDHN-NP), in comparison to PDA-NP, to trap alkylperoxyl (ROO•) and hydroperoxyl (HOO•) radicals that are involved in the propagation of peroxidation in real conditions. Our results demonstrate that PDHN-NP present a higher antioxidant efficiency with respect to PDA-NP against ROO• in water at pH 7.4 and against mixed ROO• and HOO• in acetonitrile, showing catalytic cross-termination activity. The antioxidant capacity of PDHN-NP in water is 0.8 mmol/g (ROO• radicals quenched by 1 g of PDHN-NP), with a rate constant of 3 × 105 M-1 s-1 for each reactive moiety. Quantum-mechanical calculations revealed that, thanks to the formation of a H-bond network, the quinones in PDHN-NP have a high affinity for H-atoms, thus justifying the high reactivity of PDHN-NP with HOO• observed experimentally.
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Affiliation(s)
| | | | | | - Marco Montalti
- Department of Chemistry “Giacomo Ciamician”, University of Bologna, Via Selmi 2, 40126 Bologna, Italy; (A.M.-P.); (F.M.)
| | - Riccardo Amorati
- Department of Chemistry “Giacomo Ciamician”, University of Bologna, Via Selmi 2, 40126 Bologna, Italy; (A.M.-P.); (F.M.)
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9
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Cardullo N, Monti F, Muccilli V, Amorati R, Baschieri A. Reaction with ROO• and HOO• Radicals of Honokiol-Related Neolignan Antioxidants. MOLECULES (BASEL, SWITZERLAND) 2023; 28:molecules28020735. [PMID: 36677790 PMCID: PMC9867055 DOI: 10.3390/molecules28020735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 01/05/2023] [Accepted: 01/07/2023] [Indexed: 01/15/2023]
Abstract
Honokiol is a natural bisphenol neolignan present in the bark of Magnolia officinalis, whose extracts have been employed in oriental medicine to treat several disorders, showing a variety of biological properties, including antitumor activity, potentially related to radical scavenging. Six bisphenol neolignans with structural motifs related to the natural bioactive honokiol were synthesized. Their chain-breaking antioxidant activity was evaluated in the presence of peroxyl (ROO•) and hydroperoxyl (HOO•) radicals by both experimental and computational methods. Depending on the number and position of the hydroxyl and alkyl groups present on the molecules, these derivatives are more or less effective than the reference natural compound. The rate constant of the reaction with ROO• radicals for compound 7 is two orders of magnitude greater than that of honokiol. Moreover, for compounds displaying quinonic oxidized forms, we demonstrate that the addition of 1,4 cyclohexadiene, able to generate HOO• radicals, restores their antioxidant activity, because of the reducing capability of the HOO• radicals. The antioxidant activity of the oxidized compounds in combination with 1,4-cyclohexadiene is, in some cases, greater than that found for the starting compounds towards the peroxyl radicals. This synergy can be applied to maximize the performances of these new bisphenol neolignans.
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Affiliation(s)
- Nunzio Cardullo
- Dipartimento di Scienze Chimiche, Università di Catania, V.le A. Doria 6, 95125 Catania, Italy
| | - Filippo Monti
- Istituto per la Sintesi Organica e la Fotoreattività (ISOF), Consiglio Nazionale delle Ricerche (CNR), Via Gobetti 101, 40129 Bologna, Italy
| | - Vera Muccilli
- Dipartimento di Scienze Chimiche, Università di Catania, V.le A. Doria 6, 95125 Catania, Italy
| | - Riccardo Amorati
- Dipartimento di Chimica “G. Ciamician”, Università di Bologna, Via S. Giacomo 11, 40126 Bologna, Italy
- Correspondence: (R.A.); (A.B.)
| | - Andrea Baschieri
- Istituto per la Sintesi Organica e la Fotoreattività (ISOF), Consiglio Nazionale delle Ricerche (CNR), Via Gobetti 101, 40129 Bologna, Italy
- Correspondence: (R.A.); (A.B.)
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10
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Cariola A, El Chami M, Granatieri J, Valgimigli L. Anti-Tyrosinase and Antioxidant Activity of Meroterpene Bakuchiol from Psoralea corylifolia (L.). Food Chem 2022; 405:134953. [DOI: 10.1016/j.foodchem.2022.134953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 11/08/2022] [Accepted: 11/10/2022] [Indexed: 11/18/2022]
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11
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Kaneko T, Mita Y, Nozawa-Kumada K, Yazaki M, Arisawa M, Niki E, Noguchi N, Saito Y. Antioxidant action of persulfides and polysulfides against free radical-mediated lipid peroxidation. Free Radic Res 2022; 56:677-690. [PMID: 36630595 DOI: 10.1080/10715762.2023.2165918] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Hydrogen sulfide, hydropersulfides, and hydropolysulfides have been revealed to play important physiological roles such as cell signaling and protection against oxidative stress, but the underlying mechanisms and dynamics of action remain elusive. It is generally accepted that these species act by two-electron redox mechanisms, while the involvement of one-electron redox chemistry has received less attention. In this study, the radical-scavenging activity of hydrogen persulfide, hydrogen polysulfides (HSnH n = 2-4), and diallyl- or dialkyl-sulfides (RSnR, n = 1-4) was measured. Furthermore, their antioxidant effects against free radical-mediated human plasma lipid peroxidation were assessed by measuring lipid hydroperoxides. It was found that disodium disulfide, trisulfide, and tetrasulfide acted as potent peroxyl radical scavengers, the rate constant for scavenging peroxyl radical being 3.5 × 105, 4.0 × 105, and 6.0 × 105 M-1 s-1 in PBS pH 7.4 at 37 °C respectively and that they inhibited plasma lipid peroxidation efficiently, the efficacy is increased with the catenation number. Disodium tetrasulfide was 1.5 times as reactive as Trolox toward peroxyl radical and inhibited plasma lipid peroxidation more efficiently than ascorbate and Trolox. On the other hand, diallyl- and dialkyl-sulfides did not exert significant radical-scavenging activity, nor did they inhibit lipid peroxidation efficiently, except for diallyl tetrasulfide, which suppressed plasma lipid peroxidation, despite less significantly than disodium tetrasulfide. Collectively, this study shows that hydrogen persulfide and hydrogen polysulfides act as potent radical-scavenging antioxidants and that, in addition to two-electron redox mechanisms, one electron redox reaction may also play important role in the in vivo defense against deleterious oxidative stress.
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Affiliation(s)
- Takayuki Kaneko
- Laboratory of Molecular Biology and Metabolism, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
| | - Yuichiro Mita
- The Systems Life Sciences Laboratory, Department of Medical Life Systems, Faculty of Life and Medical Sciences, Doshisha University, Kyotanabe, Japan
| | - Kanako Nozawa-Kumada
- Department of Biophysical Chemistry, Graduate School of Pharmaceutical Sciences, Tohoku University, Aoba, Sendai, Japan
| | - Masana Yazaki
- Department of Bioscience and Biotechnology, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, Fukuoka, Japan
| | - Mieko Arisawa
- Department of Bioscience and Biotechnology, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, Fukuoka, Japan
| | - Etsuo Niki
- Research Center for Advanced Science and Technology (RCAST), The University of Tokyo, Komaba, Tokyo, Japan
| | - Noriko Noguchi
- The Systems Life Sciences Laboratory, Department of Medical Life Systems, Faculty of Life and Medical Sciences, Doshisha University, Kyotanabe, Japan
| | - Yoshiro Saito
- Laboratory of Molecular Biology and Metabolism, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
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12
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Moskalenko IV, Tikhonov IV. H/D Kinetic Solvent Isotope Effect in the Oxidation of Methyl Linoleate in Triton X-100 Micelles. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY B 2022. [DOI: 10.1134/s1990793122040121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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13
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Solvent effect on activities of aryloxyl‐radical scavenging and singlet‐oxygen quenching reactions by vitamin E: Addition of water to ethanol solution. INT J CHEM KINET 2022. [DOI: 10.1002/kin.21596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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14
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Scurti S, Caretti D, Mollica F, Di Antonio E, Amorati R. Chain-Breaking Antioxidant and Peroxyl Radical Trapping Activity of Phenol-Coated Magnetic Iron Oxide Nanoparticles. Antioxidants (Basel) 2022; 11:antiox11061163. [PMID: 35740061 PMCID: PMC9219998 DOI: 10.3390/antiox11061163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 06/08/2022] [Accepted: 06/10/2022] [Indexed: 11/18/2022] Open
Abstract
Superparamagnetic iron oxide nanoparticles (SPION) are important materials for biomedical applications, and phenol capping is a common procedure to passivate their surface. As phenol capped SPION have been reported to behave as antioxidants, herein, we investigate the mechanism underlying this activity by studying the reaction with alkyl peroxyl (ROO•) radicals. SPION were prepared by coprecipitation of Fe(II) and Fe(III), using phenolic antioxidants (gallic acid, Trolox and nordihydroguaiaretic acid) as post-synthesis capping agents and by different purification procedures. The reactivity of ROO• was investigated by inhibited autoxidation studies, using styrene as an oxidizable substrate (solvent MeCN, 30 °C) and azo-bis(isobutyronitrile) as a radical initiator. While unprotected, bare SPION behaved as prooxidant, accelerating the O2 consumption of styrene autoxidation, phenol capping provided a variable antioxidant effect that was dependent upon the purification degree of the material. Thoroughly washed SPION, containing from 7% to 14% (w/w) of phenols, had a low reactivity toward peroxyl radicals, while SPION with a higher phenol content (46% to 55%) showed a strong radical trapping activity. Our results indicate that the antioxidant activity of phenol-capped SPION can be caused by its release in a solution of weakly bound phenols, and that purification plays a major role in determining the properties of these materials.
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Affiliation(s)
- Stefano Scurti
- Department of Industrial Chemistry “Toso Montanari”, University of Bologna, UdR INSTM of Bologna, Viale Risorgimento 4, 40136 Bologna, Italy; (S.S.); (D.C.)
| | - Daniele Caretti
- Department of Industrial Chemistry “Toso Montanari”, University of Bologna, UdR INSTM of Bologna, Viale Risorgimento 4, 40136 Bologna, Italy; (S.S.); (D.C.)
| | - Fabio Mollica
- Department of Chemistry “G. Ciamician”, University of Bologna, Via San Giacomo 11, 40126 Bologna, Italy; (F.M.); (E.D.A.)
| | - Erika Di Antonio
- Department of Chemistry “G. Ciamician”, University of Bologna, Via San Giacomo 11, 40126 Bologna, Italy; (F.M.); (E.D.A.)
| | - Riccardo Amorati
- Department of Chemistry “G. Ciamician”, University of Bologna, Via San Giacomo 11, 40126 Bologna, Italy; (F.M.); (E.D.A.)
- Correspondence:
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15
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On the Scavenging Ability of Scutellarein against the OOH Radical in Water and Lipid-like Environments: A Theoretical Study. Antioxidants (Basel) 2022; 11:antiox11020224. [PMID: 35204107 PMCID: PMC8868326 DOI: 10.3390/antiox11020224] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 01/20/2022] [Accepted: 01/20/2022] [Indexed: 11/16/2022] Open
Abstract
The antioxidant capability of scutellarein, a flavonoid extracted from different plants of the Scutellaria family, was computationally predicted by considering its reaction with the OOH radical in both lipid-like and water environments. The pKa and equilibrium behavior in the aqueous phase were also calculated. Different reaction mechanisms involving the most populated species were considered. The work was performed by using the density functional level of theory. The individual, total, and fraction-corrected total rate constants were obtained. The results show that scutellarein has scavenging power against the hydroperoxyl radical similar to that of Trolox, which is generally used as a reference antioxidant.
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16
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Mollica F, Lucernati R, Amorati R. Expanding the spectrum of polydopamine antioxidant activity by nitroxide conjugation. J Mater Chem B 2021; 9:9980-9988. [PMID: 34873604 DOI: 10.1039/d1tb02154k] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Polydopamine (PDA) materials are important due to their unique physicochemical properties and their potential as chemopreventive agents for diseases connected with oxidative stress. Although PDA has been suggested to display antioxidant activity, its efficacy is controversial and its mechanism of action is still unclear. Herein, we report that accurately purified PDA nanoparticles in water at pH 7.4 are unable to quench alkylperoxyls (ROO˙), which are the radicals responsible for the propagation of lipid peroxidation, despite PDA reacting with the model DPPH˙ and ABTS˙+ radicals. PDA nanoparticles prepared by copolymerization of dopamine with the dialkyl nitroxide 4-NH2TEMPO show instead good antioxidant activity, thanks to the ROO˙ trapping ability of the nitroxide. Theoretical calculations performed on a quinone-catechol dimer, reproducing the structural motive of PDA, indicate a reactivity with ROO˙ similar to catechol. These results suggest that PDA nanoparticles have an "onion-like" structure, with a catechol-rich core, which can be reached only by DPPH˙ and ABTS˙+, and a surface mainly represented by quinones. The importance of assessing the antioxidant activity by inhibited autoxidation studies is also discussed.
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Affiliation(s)
- Fabio Mollica
- Department of Chemistry "G. Ciamician", University of Bologna, Via S. Giacomo 11, 40126, Bologna, Italy.
| | - Rosa Lucernati
- Department of Chemistry "G. Ciamician", University of Bologna, Via S. Giacomo 11, 40126, Bologna, Italy.
| | - Riccardo Amorati
- Department of Chemistry "G. Ciamician", University of Bologna, Via S. Giacomo 11, 40126, Bologna, Italy.
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17
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Jodko-Piórecka K, Sikora B, Kluzek M, Przybylski P, Litwinienko G. Antiradical Activity of Dopamine, L-DOPA, Adrenaline, and Noradrenaline in Water/Methanol and in Liposomal Systems. J Org Chem 2021; 87:1791-1804. [PMID: 34871499 PMCID: PMC8822484 DOI: 10.1021/acs.joc.1c02308] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
![]()
Catecholamines play
a crucial role in signal transduction and are
also expected to act as endogeneous antioxidants, but the mechanism
of their antioxidant action is not fully understood. Here, we describe
the impact of pH on the kinetics of reaction of four catecholamines
(L-DOPA, dopamine, adrenaline, and noradrenaline) with model 2,2-diphenyl-1-picrylhydrazyl
radical (dpph•) in methanol/water. The increase
in pH from 5.5 to 7.4 is followed by a 2 order of magnitude increase
in the rate constant, e.g., for dopamine (DA) kpH5.5 = 1,200 M–1 s–1 versus kpH7.4 = 170,000 M–1 s–1, and such rate acceleration is attributed to a fast
electron transfer from the DA anion to dpph•. We
also proved that at pH 7.0 DA breaks the peroxidation chain of methyl
linoleate in liposomes assembled from neutral and negatively charged
phospholipids. In contrast to no inhibitory effect during peroxidation
in non-ionic emulsions, in bilayers one molecule of DA traps approximately
four peroxyl radicals, with a rate constant kinh >103 M–1 s–1. Our results from a homogeneous system and bilayers prove that catecholamines
act as effective, radical trapping antioxidants with activity depending
on the ionization status of the catechol moiety, as well as microenvironment:
organization of the lipid system (emulsions vs bilayers) and interactions
of catecholamines with the biomembrane.
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Affiliation(s)
| | - Bożena Sikora
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland.,Laboratory of Biological Physics, Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw, Poland
| | - Monika Kluzek
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland.,Department of Materials and Interfaces, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Paweł Przybylski
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland
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18
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Baschieri A, Amorati R. Methods to Determine Chain-Breaking Antioxidant Activity of Nanomaterials beyond DPPH •. A Review. Antioxidants (Basel) 2021; 10:1551. [PMID: 34679687 PMCID: PMC8533328 DOI: 10.3390/antiox10101551] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 09/27/2021] [Accepted: 09/28/2021] [Indexed: 12/15/2022] Open
Abstract
This review highlights the progress made in recent years in understanding the mechanism of action of nanomaterials with antioxidant activity and in the chemical methods used to evaluate their activity. Nanomaterials represent one of the most recent frontiers in the research for improved antioxidants, but further development is hampered by a poor characterization of the ''antioxidant activity'' property and by using oversimplified chemical methods. Inhibited autoxidation experiments provide valuable information about the interaction with the most important radicals involved in the lipid oxidation, namely alkylperoxyl and hydroperoxyl radicals, and demonstrate unambiguously the ability to stop the oxidation of organic materials. It is proposed that autoxidation methods should always complement (and possibly replace) the use of assays based on the quenching of stable radicals (such as DPPH• and ABTS•+). The mechanisms leading to the inhibition of the autoxidation (sacrificial and catalytic radical trapping antioxidant activity) are described in the context of nanoantioxidants. Guidelines for the selection of the appropriate testing conditions and of meaningful kinetic analysis are also given.
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Affiliation(s)
- Andrea Baschieri
- Istituto per la Sintesi Organica e la Fotoreattività, Consiglio Nazionale delle Ricerche (ISOF-CNR), Via P. Gobetti 101, 40129 Bologna, Italy;
| | - Riccardo Amorati
- Department of Chemistry “G. Ciamician”, University of Bologna, Via S. Giacomo 11, 40126 Bologna, Italy
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19
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Ruiz-Hernández K, Sosa-Morales ME, Cerón-García A, Gómez-Salazar JA. Physical, Chemical and Sensory Changes in Meat and Meat Products Induced by the Addition of Essential Oils: A Concise Review. FOOD REVIEWS INTERNATIONAL 2021. [DOI: 10.1080/87559129.2021.1939369] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Karla Ruiz-Hernández
- Posgrado En Biociencias, Departamento De Alimentos, División De Ciencias De La Vida, Campus Irapuato-Salamanca, Universidad De Guanajuato, Irapuato, Guanajuato, Mexico
| | - María Elena Sosa-Morales
- Posgrado En Biociencias, Departamento De Alimentos, División De Ciencias De La Vida, Campus Irapuato-Salamanca, Universidad De Guanajuato, Irapuato, Guanajuato, Mexico
| | - Abel Cerón-García
- Posgrado En Biociencias, Departamento De Alimentos, División De Ciencias De La Vida, Campus Irapuato-Salamanca, Universidad De Guanajuato, Irapuato, Guanajuato, Mexico
| | - Julián Andrés Gómez-Salazar
- Posgrado En Biociencias, Departamento De Alimentos, División De Ciencias De La Vida, Campus Irapuato-Salamanca, Universidad De Guanajuato, Irapuato, Guanajuato, Mexico
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20
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Genovese D, Baschieri A, Vona D, Baboi RE, Mollica F, Prodi L, Amorati R, Zaccheroni N. Nitroxides as Building Blocks for Nanoantioxidants. ACS APPLIED MATERIALS & INTERFACES 2021; 13:31996-32004. [PMID: 34156238 PMCID: PMC8289242 DOI: 10.1021/acsami.1c06674] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Nitroxides are an important class of radical trapping antioxidants whose promising biological activities are connected to their ability to scavenge peroxyl (ROO•) radicals. We have measured the rate constants of the reaction with ROO• (kinh) for a series of 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) derivatives as 5.1 × 106, 1.1 × 106, 5.4 × 105, 3.7 × 105, 1.1 × 105, 1.9 × 105, and 5.6 × 104 M-1 s-1 for -H, -OH, -NH2, -COOH, -NHCOCH3, -CONH(CH2)3CH3, and ═O substituents in the 4 position, with a good Marcus relationship between log (kinh) and E° for the R2NO•/R2NO+ couple. Newly synthesized Pluronic-silica nanoparticles (PluS) having nitroxide moieties covalently bound to the silica surface (PluS-NO) through a TEMPO-CONH-R link and coumarin dyes embedded in the silica core, has kinh = 1.5 × 105 M-1 s-1. Each PluS-bound nitroxide displays an inhibition duration nearly double that of a structurally related "free" nitroxide. As each PluS-NO particle bears an average of 30 nitroxide units, this yields an overall ≈60-fold larger inhibition of the PluS-NO nanoantioxidant compared to the molecular analogue. The implications of these results for the development of novel nanoantioxidants based on nitroxide derivatives are discussed, such as the choice of the best linkage group and the importance of the regeneration cycle in determining the duration of inhibition.
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Affiliation(s)
- Damiano Genovese
- Department
of Chemistry “Giacomo Ciamician”, University of Bologna, via Selmi 2, 40126 Bologna, Italy
| | - Andrea Baschieri
- Istituto
per la Sintesi Organica e la Fotoreattività (ISOF), Consiglio Nazionale delle Ricerche (CNR), via Gobetti 101, 40129 Bologna, Italy
| | - Danilo Vona
- Department
of Chemistry, University of Bari, via Orabona 4, I-70126 Bari, Italy
| | - Ruxandra Elena Baboi
- Department
of Chemistry “Giacomo Ciamician”, University of Bologna, via San Giacomo 11, 40126 Bologna, Italy
| | - Fabio Mollica
- Department
of Chemistry “Giacomo Ciamician”, University of Bologna, via San Giacomo 11, 40126 Bologna, Italy
| | - Luca Prodi
- Department
of Chemistry “Giacomo Ciamician”, University of Bologna, via Selmi 2, 40126 Bologna, Italy
| | - Riccardo Amorati
- Department
of Chemistry “Giacomo Ciamician”, University of Bologna, via San Giacomo 11, 40126 Bologna, Italy
| | - Nelsi Zaccheroni
- Department
of Chemistry “Giacomo Ciamician”, University of Bologna, via Selmi 2, 40126 Bologna, Italy
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21
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Guo Y, Baschieri A, Mollica F, Valgimigli L, Cedrowski J, Litwinienko G, Amorati R. Hydrogen Atom Transfer from HOO . to ortho-Quinones Explains the Antioxidant Activity of Polydopamine. Angew Chem Int Ed Engl 2021; 60:15220-15224. [PMID: 33876878 PMCID: PMC8362028 DOI: 10.1002/anie.202101033] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 04/09/2021] [Indexed: 12/24/2022]
Abstract
Melanins are stable and non-toxic biomaterials with a great potential as chemopreventive agents for diseases connected with oxidative stress, but the mechanism of their antioxidant action is unclear. Herein, we show that polydopamine (PDA), a well-known synthetic melanin, becomes an excellent trap for alkylperoxyl radicals (ROO. , typically formed during autoxidation of lipid substrates) in the presence of hydroperoxyl radicals (HOO. ). The key reaction explaining this peculiar antioxidant activity is the reduction of the ortho-quinone moieties present in PDA by the reaction with HOO. . This reaction occurs via a H-atom transfer mechanism, as demonstrated by the large kinetic solvent effect of the reaction of a model quinone (3,5-di-tert-butyl-1,2-benzoquinone) with HOO. (k=1.5×107 and 1.1×105 M-1 s-1 in PhCl and MeCN). The chemistry disclosed herein is an important step to rationalize the redox-mediated bioactivity of melanins and of quinones.
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Affiliation(s)
- Yafang Guo
- Department of Chemistry “G. Ciamician”University of BolognaVia S. Giacomo 1140126BolognaItaly
| | - Andrea Baschieri
- Department of Chemistry “G. Ciamician”University of BolognaVia S. Giacomo 1140126BolognaItaly
| | - Fabio Mollica
- Department of Chemistry “G. Ciamician”University of BolognaVia S. Giacomo 1140126BolognaItaly
| | - Luca Valgimigli
- Department of Chemistry “G. Ciamician”University of BolognaVia S. Giacomo 1140126BolognaItaly
| | - Jakub Cedrowski
- Faculty of ChemistryUniversity of WarsawPasteura 102-093WarsawPoland
| | | | - Riccardo Amorati
- Department of Chemistry “G. Ciamician”University of BolognaVia S. Giacomo 1140126BolognaItaly
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22
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Guo Y, Baschieri A, Mollica F, Valgimigli L, Cedrowski J, Litwinienko G, Amorati R. Hydrogen Atom Transfer from HOO
.
to
ortho
‐Quinones Explains the Antioxidant Activity of Polydopamine. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202101033] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- Yafang Guo
- 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
| | - Fabio Mollica
- 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
| | - Jakub Cedrowski
- Faculty of Chemistry University of Warsaw Pasteura 1 02-093 Warsaw Poland
| | | | - Riccardo Amorati
- Department of Chemistry “G. Ciamician” University of Bologna Via S. Giacomo 11 40126 Bologna Italy
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23
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Suzuki T, Sato A, Oshita H, Yajima T, Tani F, Abe H, Mieda-Higa K, Yanagisawa S, Ogura T, Shimazaki Y. Formation of Ni(II)-phenoxyl radical complexes by O 2: a mechanistic insight into the reaction of Ni(II)-phenol complexes with O 2. Dalton Trans 2021; 50:5161-5170. [PMID: 33881085 DOI: 10.1039/d1dt00105a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
A reaction of Ni(ClO4)2·6H2O with a tripodal ligand having two di(tert-butyl)phenol moieties, H2tbuL, and 1 equivalent of triethylamine in CH2Cl2/CH3OH (1 : 1, v/v) under N2 gave a NiII-(phenol)(phenolate) complex, [Ni(HtbuL)(CH3OH)2]ClO4. The formation of the NiII-phenoxyl radical complex by O2 was observed in the reaction of this complex in the solid state. On the other hand, the NiII-phenoxyl radical complex [Ni(Me2NL)(CH3OH)2]ClO4 was obtained by the reaction of H2Me2NL having a p-(dimethylamino)phenol moiety with Ni(ClO4)2·6H2O in a similar procedure under O2, through the oxidation of the NiII-(phenol)(phenolate) complex. However, a direct redox reaction of the NiII ion could not be detected in the phenoxyl radical formation. The results of the reaction kinetics, XAS and X-ray structure analyses suggested that the O2 oxidation from the NiII-(phenol)(phenolate) complex to the NiII-phenoxyl radical complex occurs via the proton transfer-electron transfer (PT-ET) type mechanism of the phenol moiety weakly coordinated to the nickel ion.
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Affiliation(s)
- Takashi Suzuki
- Graduate School of Science and Engineering, Ibaraki University, Mito 310-8512, Japan.
| | - Akari Sato
- Graduate School of Science and Engineering, Ibaraki University, Mito 310-8512, Japan.
| | - Hiromi Oshita
- Faculty of Chemistry of Functional Molecules, Konan University, Higashinada-ku, Kobe 658-8501, Japan
| | - Tatsuo Yajima
- Faculty of Chemistry, Materials and Bioengineering, Kansai University, Suita, Osaka 564-8680, Japan
| | - Fumito Tani
- Institute for Materials Chemistry and Engineering, Kyushu University, Nishi-Ku, Fukuoka 819-0395, Japan
| | - Hitoshi Abe
- Graduate School of Science and Engineering, Ibaraki University, Mito 310-8512, Japan. and Institute of Materials Structure Science (IMSS), High Energy Accelerator Research Organization (KEK) 1-1 Oho, Tsukuba, Ibaraki 305-0801, Japan and Department of Materials Structure Science, School of High Energy Accelerator Science, SOKENDAI (the Graduate University for Advanced Studies), 1-1 Oho, Tsukuba, Ibaraki 305-0801, Japan
| | - Kaoru Mieda-Higa
- Graduate School of Life Science, University of Hyogo, Kamigori, Hyogo 678-1297, Japan
| | - Sachiko Yanagisawa
- Graduate School of Life Science, University of Hyogo, Kamigori, Hyogo 678-1297, Japan
| | - Takashi Ogura
- Graduate School of Life Science, University of Hyogo, Kamigori, Hyogo 678-1297, Japan
| | - Yuichi Shimazaki
- Graduate School of Science and Engineering, Ibaraki University, Mito 310-8512, Japan.
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25
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Guo Y, Baschieri A, Amorati R, Valgimigli L. Synergic antioxidant activity of γ-terpinene with phenols and polyphenols enabled by hydroperoxyl radicals. Food Chem 2020; 345:128468. [PMID: 33341300 DOI: 10.1016/j.foodchem.2020.128468] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 10/16/2020] [Accepted: 10/20/2020] [Indexed: 01/09/2023]
Abstract
Antioxidant interactions of γ-terpinene with α-tocopherol mimic 2,2,5,7,8-pentamethyl-6-chromanol (PMHC) and caffeic acid phenethyl ester (CAPE), used as models, respectively, of mono- and poly-phenols were demonstrated by differential oximetry during the inhibited autoxidation of model substrates: stripped sunflower oil, squalene, and styrene. With all substrates, γ-terpinene acts synergistically regenerating the chain-breaking antioxidants PMHC and CAPE from their radicals, via the formation of hydroperoxyl radicals. The inhibition duration for mixtures PMHC/γ-terpinene and CAPE/γ-terpinene increased with γ-terpinene concentration, while rate constants for radical-trapping were unchanged by γ-terpinene, being 3.1 × 106 and 4.8 × 105 M-1s-1 for PMHC and CAPE in chlorobenzene (30 °C). Using 3,5-di-tert-butylcatechol and 3,5-di-tert-butyl-1,2-bezoquinone we demonstrate that γ-terpinene can reduce quinones to catechols enabling their antioxidant activity. The different synergy mechanism of γ-terpinene with mono- and poly-phenolic antioxidants is discussed and its relevance is proven in homogenous lipids using natural α-tocopherol and hydroxytyrosol as antioxidants, calling for further studies in heterogenous food products.
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Affiliation(s)
- Yafang Guo
- University of Bologna, Department of Chemistry "G. Ciamician", Via S. Giacomo 11, 40126 Bologna, Italy
| | - Andrea Baschieri
- University of Bologna, Department of Chemistry "G. Ciamician", Via S. Giacomo 11, 40126 Bologna, Italy
| | - Riccardo Amorati
- University of Bologna, Department of Chemistry "G. Ciamician", Via S. Giacomo 11, 40126 Bologna, Italy
| | - Luca Valgimigli
- University of Bologna, Department of Chemistry "G. Ciamician", Via S. Giacomo 11, 40126 Bologna, Italy.
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26
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27
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Zeng P, Zheng Y, Chen S, Liu H, Li R, Peng T. Asymmetric zinc porphyrin derivatives bearing three pseudo-pyrimidine meso-position substituents and their photosensitization for H 2 evolution. NEW J CHEM 2020. [DOI: 10.1039/d0nj02056g] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
ZnPy-6 has lower steric hindrance than ZnPy-5 when the N atoms of the pseudo-pyrimidines combine with g-C3N4 and AA, and thus it exhibits better photosensitization.
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Affiliation(s)
- Peng Zeng
- School of Food and Pharmaceutical Engineering
- Zhaoqing University
- Zhaoqing 526061
- P. R. China
- College of Chemistry and Molecular Sciences
| | - Ya Zheng
- College of Chemistry and Molecular Sciences
- Wuhan University
- Wuhan 430072
- P. R. China
| | - Shengtao Chen
- College of Chemistry and Molecular Sciences
- Wuhan University
- Wuhan 430072
- P. R. China
| | - Haoran Liu
- College of Chemistry and Molecular Sciences
- Wuhan University
- Wuhan 430072
- P. R. China
| | - Renjie Li
- College of Chemistry and Molecular Sciences
- Wuhan University
- Wuhan 430072
- P. R. China
| | - Tianyou Peng
- College of Chemistry and Molecular Sciences
- Wuhan University
- Wuhan 430072
- P. R. China
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Viglianisi C, Scarlini A, Tofani L, Menichetti S, Baschieri A, Amorati R. Magnetic nanoantioxidants with improved radical-trapping stoichiometry as stabilizers for inhibition of peroxide formation in ethereal solvents. Sci Rep 2019; 9:17219. [PMID: 31748620 PMCID: PMC6868006 DOI: 10.1038/s41598-019-53531-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 10/31/2019] [Indexed: 01/22/2023] Open
Abstract
Graphite-coated magnetic cobalt nanoparticles (CoNPs) decorated with hindered phenolic antioxidant analogues of 2,6-di-tert-butyl-4-methylphenol (BHT, E321) provided easily removable nanoantioxidants capable of preventing the autoxidation of organic solvents as tetrahydrofuran (THF).
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Affiliation(s)
- Caterina Viglianisi
- Department of Chemistry "U. Schiff", University of Florence, Via della Lastruccia 3-13, 50019, Sesto Fiorentino, Firenze, Italy.
| | - Alessia Scarlini
- Department of Chemistry "U. Schiff", University of Florence, Via della Lastruccia 3-13, 50019, Sesto Fiorentino, Firenze, Italy
| | - Lorenzo Tofani
- Department of Chemistry "U. Schiff", University of Florence, Via della Lastruccia 3-13, 50019, Sesto Fiorentino, Firenze, Italy
| | - Stefano Menichetti
- Department of Chemistry "U. Schiff", University of Florence, Via della Lastruccia 3-13, 50019, Sesto Fiorentino, Firenze, Italy
| | - Andrea Baschieri
- Department of Chemistry "G. Ciamician", University of Bologna, Via S. Giacomo 11, 40126, Bologna, Italy
| | - Riccardo Amorati
- Department of Chemistry "G. Ciamician", University of Bologna, Via S. Giacomo 11, 40126, Bologna, Italy
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Fontana A, Guernelli S, Di Crescenzo A, Di Profio P, Palomba F, De Crescentini L, Baschieri A, Amorati R. Cardanol-like co-surfactants solubilized in pegylated micelles keep their antioxidant activity and preserve polyethylene glycol chains from oxidation. J Mol Liq 2019. [DOI: 10.1016/j.molliq.2019.111465] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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Abstract
The rationale and scope of the main issues of antioxidant measurement are presented, with basic definitions and terms in antioxidant research (such as reactive species and related antioxidative defenses, oxidative stress, and antioxidant activity and capacity) in a historical background. An overview of technical problems and expectations is given in terms of interpretation of results, precision and comparability of methods, capability of simulating physical reality, and analytical performance (sensitivity, selectivity, etc.). Current analytical methods for measuring antioxidant and antiradical activity are classified from various viewpoints. Reaction kinetics and thermodynamics of current analytical methods are discussed, describing physicochemical aspects of antioxidant action and measurement. Controversies and limitations of the widely used antioxidant assays are elaborated in detail. Emerging techniques in antioxidant testing (e.g., nanotechnology, sensors, electrochemistry, chemometry, and hyphenated methods) are broadly introduced. Finally, hints for the selection of suitable assays (i.e., preferable for a specific purpose) and future prospects are given.
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Affiliation(s)
- Reşat Apak
- Department of Chemistry, Faculty of Engineering , Istanbul University-Cerrahpasa , Avcilar, 34320 Istanbul , Turkey
- Turkish Academy of Sciences (TUBA) , Piyade Street 27 , Cankaya, 06690 Ankara , Turkey
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Baschieri A, Pizzol R, Guo Y, Amorati R, Valgimigli L. Calibration of Squalene, p-Cymene, and Sunflower Oil as Standard Oxidizable Substrates for Quantitative Antioxidant Testing. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2019; 67:6902-6910. [PMID: 31132263 DOI: 10.1021/acs.jafc.9b01400] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The autoxidation kinetics of stripped sunflower oil (SSO), squalene (SQ), and p-cymene ( p-C) initiated by 2,2'-azobis(isobutyronitrile) at 303 K were investigated under controlled conditions by differential oximetry in order to build reference model systems that are representative of the natural variability of oxidizable materials, for quantitative antioxidant testing. Rate constants for oxidative chain propagation ( kp) and chain termination (2 kt) and the oxidizability ( kp/√2 kt) were measured using 2,6-di- tert-butyl-4-methoxyphenol, 2,2,5,7,8-pentamethyl-6-chromanol, BHT, and 4-methoxyphenol as reference antioxidants. Measured values of kp (M-1 s-1)/2 kt (M-1 s-1)/oxidizability (M-1/2 s-1/2) at 303 K in chlorobenzene were 66.9/3.45 × 106/3.6 × 10-2, 68.0/7.40 × 106/2.5 × 10-2, and 0.83/2.87 × 106/4.9 × 10-4, respectively, for SSO, SQ, and p-C. Quercetin, magnolol, caffeic acid phenethyl ester, and 2,4,6-trimethylphenol were investigated to validate calibrations. The distinctive usefulness of the three substrates in testing antioxidants is discussed.
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Affiliation(s)
- Andrea Baschieri
- Department of Chemistry "G. Ciamician" , University of Bologna , Via S. Giacomo 11 , 40126 Bologna , Italy
| | - Romeo Pizzol
- Department of Chemistry "G. Ciamician" , University of Bologna , Via S. Giacomo 11 , 40126 Bologna , Italy
| | - Yafang Guo
- Department of Chemistry "G. Ciamician" , University of Bologna , Via S. Giacomo 11 , 40126 Bologna , 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
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Baschieri A, Amorati R, Benelli T, Mazzocchetti L, D'Angelo E, Valgimigli L. Enhanced Antioxidant Activity under Biomimetic Settings of Ascorbic Acid Included in Halloysite Nanotubes. Antioxidants (Basel) 2019; 8:E30. [PMID: 30691231 PMCID: PMC6406349 DOI: 10.3390/antiox8020030] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2018] [Revised: 01/21/2019] [Accepted: 01/24/2019] [Indexed: 12/31/2022] Open
Abstract
Antioxidant activity of native vitamin C (ascorbic acid, AH₂) is hampered by instability in solution. Selective loading of AH₂ into the inner lumen of natural halloysite nanotubes (HNT) yields a composite nanoantioxidant (HNT/AH₂), which was characterized and investigated for its reactivity with the persistent 1,1-diphenyl-2-picrylhydrazyl (DPPH•) radical and with transient peroxyl radicals in the inhibited autoxidation of organic substrates, both in organic solution (acetonitrile) and in buffered (pH 7.4) water in comparison with native AH₂. HNT/AH₂ showed excellent antioxidant performance being more effective than native ascorbic acid by 131% in acetonitrile and 290% (three-fold) in aqueous solution, under identical settings. Reaction with peroxyl radicals has a rate constant of 1.4 × 10⁶ M-1 s-1 and 5.1 × 10⁴ M-1 s-1, respectively, in buffered water (pH 7.4) and acetonitrile, at 30 °C. Results offer physical understanding of the factors governing HNT/AH₂ reactivity. Improved performance of HNT/AH₂ is unprecedented among forms of stabilized ascorbic acid and its relevance is discussed on kinetic grounds.
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Affiliation(s)
- Andrea Baschieri
- Department of Chemistry "G. Ciamician", University of Bologna, Via S. Giacomo 11, I-40126 Bologna, Italy.
| | - Riccardo Amorati
- Department of Chemistry "G. Ciamician", University of Bologna, Via S. Giacomo 11, I-40126 Bologna, Italy.
| | - Tiziana Benelli
- Department of Industrial Chemistry "Toso Montanari", University of Bologna, Viale Risorgimento 4, I-40136 Bologna, Italy.
| | - Laura Mazzocchetti
- Department of Industrial Chemistry "Toso Montanari", University of Bologna, Viale Risorgimento 4, I-40136 Bologna, Italy.
| | - Emanuele D'Angelo
- Department of Industrial Chemistry "Toso Montanari", University of Bologna, Viale Risorgimento 4, I-40136 Bologna, Italy.
| | - Luca Valgimigli
- Department of Chemistry "G. Ciamician", University of Bologna, Via S. Giacomo 11, I-40126 Bologna, Italy.
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Foti MC, Amorati R, Baschieri A, Rocco C. Singlet oxygen quenching- and chain-breaking antioxidant-properties of a quercetin dimer able to prevent age-related macular degeneration. Biophys Chem 2018; 243:17-23. [PMID: 30352336 DOI: 10.1016/j.bpc.2018.10.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Revised: 09/18/2018] [Accepted: 10/03/2018] [Indexed: 01/07/2023]
Abstract
A dimer of quercetin prepared through a Mannich reaction protects pyridinium bisretinoid A2E from photooxidation at 430 nm in aqueous medium at pH 7.4. In the presence of light and O2, A2E is quickly attacked by 1O2 produced in situ (by excited A2E) to give nonaoxirane and other oxygenated compounds which can be involved in diseases of the macula. Peroxyl radicals might have only a marginal role on the photooxidation of A2E. The dimer is actually a potent quencher of 1O2 with a rate constant kQ of 8.5 × 108 M-1 s-1 in methanol at room temperature. On the other hand, its antioxidant abilities against ROO· radicals are quite limited since kROO· = 7.3 × 105 M-1 s-1 (in buffer solution at pH 7.4), the value being essentially identical to that of quercetin. The quenching of 1O2 by the dimer is therefore the main reason for the A2E protection and prevention of age-related macular degeneration.
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Affiliation(s)
- Mario C Foti
- Istituto di Chimica Biomolecolare del CNR, via P. Gaifami 18, I-95126 Catania, Italy.
| | - Riccardo Amorati
- 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
| | - Concetta Rocco
- Istituto di Chimica Biomolecolare del CNR, via P. Gaifami 18, I-95126 Catania, Italy
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pH Effect and Chemical Mechanisms of Antioxidant Higenamine. Molecules 2018; 23:molecules23092176. [PMID: 30158440 PMCID: PMC6225313 DOI: 10.3390/molecules23092176] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Revised: 08/22/2018] [Accepted: 08/25/2018] [Indexed: 02/07/2023] Open
Abstract
In this article, we determine the pH effect and chemical mechanism of antioxidant higenamine by using four spectrophotometric assays: (1) 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide radical (PTIO•)-scavenging assay (at pH 4.5, 6.0, and 7.4); (2) Fe3+-reducing power assay; (3) Cu2+-reducing power assay; and (4) 1,1-diphenyl-2-picryl-hydrazyl (DPPH•)-scavenging assay. The DPPH•-scavenging reaction product is further analyzed by ultra-performance liquid chromatography, coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UPLC-ESI-Q-TOF-MS/MS) technology. In the four spectrophotometric assays, higenamine showed good dose-response curves; however, its IC50 values were always lower than those of Trolox. In UPLC-ESI-Q-TOF-MS/MS analysis, the higenamine reaction product with DPPH• displayed three chromatographic peaks (retention time = 0.969, 1.078, and 1.319 min). The first gave m/z 541.2324 and 542.2372 MS peaks; while the last two generated two similar MS peaks (m/z 663.1580 and 664.1885), and two MS/MS peaks (m/z 195.9997 and 225.9971). In the PTIO•-scavenging assays, higenamine greatly decreased its IC50 values with increasing pH. In conclusion, higenamine is a powerful antioxidant—it yields at least two types of final products (i.e., higenamine-radical adduct and higenamine-higenamine dimer). In aqueous media, higenamine may exert its antioxidant action via electron-transfer and proton-transfer pathways. However, its antioxidant action is markedly affected by pH. This is possibly because lower pH value weakens its proton-transfer pathway via ionization suppression by solution H+, and its electron-transfer pathway by withdrawing the inductive effect (-I) from protonated N-atom. These findings will aid the correct use of alkaloid antioxidants.
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Baschieri A, Valgimigli L, Gabbanini S, DiLabio GA, Romero-Montalvo E, Amorati R. Extremely Fast Hydrogen Atom Transfer between Nitroxides and HOO· Radicals and Implication for Catalytic Coantioxidant Systems. J Am Chem Soc 2018; 140:10354-10362. [DOI: 10.1021/jacs.8b06336] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Andrea Baschieri
- 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
| | - Simone Gabbanini
- R&D division, BeC s.r.l. Via C. Monteverdi 49, 47122 Forlì, Italy
| | - Gino A. DiLabio
- Department of Chemistry, University of British Columbia, 3247 University Way, Kelowna, British Columbia V1V 1V7, Canada
- Faculty of Management, University of British Columbia, 1137 Alumni Avenue, Kelowna, British Columbia V1V 1V7, Canada
| | - Eduardo Romero-Montalvo
- Department of Chemistry, University of British Columbia, 3247 University Way, Kelowna, British Columbia V1V 1V7, Canada
| | - Riccardo Amorati
- Department of Chemistry “G. Ciamician”, University of Bologna, Via S. Giacomo 11, 40126 Bologna, Italy
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Li X, Chen B, Zhao X, Chen D. 2-Phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide Radical (PTIO•) Trapping Activity and Mechanisms of 16 Phenolic Xanthones. Molecules 2018; 23:molecules23071692. [PMID: 29997352 PMCID: PMC6100357 DOI: 10.3390/molecules23071692] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Revised: 07/08/2018] [Accepted: 07/10/2018] [Indexed: 12/26/2022] Open
Abstract
This study used the 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide radical (PTIO•) trapping model to study the antioxidant activities of 16 natural xanthones in aqueous solution, including garcinone C, γ-mangostin, subelliptenone G, mangiferin, 1,6,7-trihydroxy-xanthone, 1,2,5-trihydroxyxanthone, 1,5,6-trihydroxyxanthone, norathyriol, 1,3,5,6-tetrahydroxy-xanthone, isojacareubin, 1,3,5,8-tetrahydroxyxanthone, isomangiferin, 2-hydroxyxanthone, 7-O-methylmangiferin, neomangiferin, and lancerin. It was observed that most of the 16 xanthones could scavenge the PTIO• radical in a dose-dependent manner at pH 4.5 and 7.4. Among them, 12 xanthones of the para-di-OHs (or ortho-di-OHs) type always exhibited lower half maximal inhibitory concentration (IC50) values than those not of the para-di-OHs (or ortho-di-OHs) type. Ultra-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UPLC-ESI-Q-TOF-MS/MS) analysis revealed that most of these xanthones gave xanthone-xanthone dimers after incubation with PTIO•, except for neomangiferin. Based on these data, we concluded that the antioxidant activity of phenolic xanthone may be mediated by electron-transfer (ET) plus H⁺-transfer mechanisms. Through these mechanisms, some xanthones can further dimerize unless they bear huge substituents with steric hindrance. Four substituent types (i.e., para-di-OHs, 5,6-di-OHs, 6,7-di-OHs, and 7,8-di-OHs) dominate the antioxidant activity of phenolic xanthones, while other substituents (including isoprenyl and 3-hydroxy-3-methylbutyl substituents) play a minor role as long as they do not break the above four types.
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Affiliation(s)
- Xican Li
- School of Chinese Herbal Medicine, Guangzhou University of Chinese Medicine, Waihuan East Road No. 232, Guangzhou Higher Education Mega Center, Guangzhou 510006, China.
- Innovative Research & Development Laboratory of TCM, Guangzhou University of Chinese Medicine, Waihuan East Road No. 232, Guangzhou Higher Education Mega Center, Guangzhou 510006, China.
| | - Ban Chen
- School of Chinese Herbal Medicine, Guangzhou University of Chinese Medicine, Waihuan East Road No. 232, Guangzhou Higher Education Mega Center, Guangzhou 510006, China.
- Innovative Research & Development Laboratory of TCM, Guangzhou University of Chinese Medicine, Waihuan East Road No. 232, Guangzhou Higher Education Mega Center, Guangzhou 510006, China.
| | - Xiaojun Zhao
- School of Chinese Herbal Medicine, Guangzhou University of Chinese Medicine, Waihuan East Road No. 232, Guangzhou Higher Education Mega Center, Guangzhou 510006, China.
- Innovative Research & Development Laboratory of TCM, Guangzhou University of Chinese Medicine, Waihuan East Road No. 232, Guangzhou Higher Education Mega Center, Guangzhou 510006, China.
| | - Dongfeng Chen
- School of Basic Medical Science, Guangzhou University of Chinese Medicine, Waihuan East Road No. 232, Guangzhou Higher Education Mega Center, Guangzhou 510006, China.
- The Research Center of Basic Integrative Medicine, Guangzhou University of Chinese Medicine, Waihuan East Road No. 232, Guangzhou Higher Education Mega Center, Guangzhou 510006, China.
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Mukai K, Bandoh Y, Ito J, Kobayashi E, Nakagawa K, Nagaoka SI. Kinetic Study of the Scavenging Reaction of the Aroxyl Radical by Eight Kinds of Vegetable Oils in Solution. J AM OIL CHEM SOC 2018. [DOI: 10.1002/aocs.12076] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Kazuo Mukai
- Department of Chemistry, Faculty of Science; Ehime University, Bunkyo-cho 2-5; Matsuyama 790-8577 Japan
| | - Yuki Bandoh
- Department of Chemistry, Faculty of Science; Ehime University, Bunkyo-cho 2-5; Matsuyama 790-8577 Japan
| | - Junya Ito
- Food and Biodynamic Chemistry Laboratory, Graduate School of Agricultural Science; Tohoku University, 1 - 1 Tsutsumidori-Amamiyamachi, Aobaku; Sendai 980-0845 Japan
| | - Eri Kobayashi
- Food and Biodynamic Chemistry Laboratory, Graduate School of Agricultural Science; Tohoku University, 1 - 1 Tsutsumidori-Amamiyamachi, Aobaku; Sendai 980-0845 Japan
| | - Kiyotaka Nakagawa
- Food and Biodynamic Chemistry Laboratory, Graduate School of Agricultural Science; Tohoku University, 1 - 1 Tsutsumidori-Amamiyamachi, Aobaku; Sendai 980-0845 Japan
| | - Shin-ichi Nagaoka
- Department of Chemistry, Faculty of Science; Ehime University, Bunkyo-cho 2-5; Matsuyama 790-8577 Japan
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Amorati R, Valgimigli L. Methods To Measure the Antioxidant Activity of Phytochemicals and Plant Extracts. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2018; 66:3324-3329. [PMID: 29557653 DOI: 10.1021/acs.jafc.8b01079] [Citation(s) in RCA: 84] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Measurement of antioxidant properties in plant-derived compounds requires appropriate methods that address the mechanism of antioxidant activity and focus on the kinetics of the reactions involving the antioxidants. Methods based on inhibited autoxidations are the most suited for chain-breaking antioxidants and for termination-enhancing antioxidants, while different specific studies are needed for preventive antioxidants. A selection of chemical testing methods is critically reviewed, highlighting their advantages and limitations and discussing their usefulness to investigate both pure molecules and raw extracts. The influence of the reaction medium on antioxidants' performance is also addressed.
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Affiliation(s)
- Riccardo Amorati
- University of Bologna , Department of Chemistry "G. Ciamician" , Via S. Giacomo 11 , 40126 Bologna , Italy
| | - Luca Valgimigli
- University of Bologna , Department of Chemistry "G. Ciamician" , Via S. Giacomo 11 , 40126 Bologna , Italy
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Abstract
Nanomaterials represent one of the most promising frontiers in the research for improved antioxidants. Some nanomaterials, including organic (i.e. melanin, lignin) metal oxides (i.e. cerium oxide) or metal (i.e. gold, platinum) based nanoparticles, exhibit intrinsic redox activity that is often associated with radical trapping and/or with superoxide dismutase-like and catalase-like activities. Redox inactive nanomaterials can be transformed into antioxidants by grafting low molecular weight antioxidants on them. Herein, we propose a classification of nanoantioxidants based on their mechanism of action, and we review the chemical methods used to measure antioxidant activity by providing a rationale of the chemistry behind them.
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Affiliation(s)
- Luca Valgimigli
- Department of Chemistry "G. Ciamician", University of Bologna, Via S. Giacomo 11, Bologna 40126, Italy.
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Griesser M, Shah R, Van Kessel AT, Zilka O, Haidasz EA, Pratt DA. The Catalytic Reaction of Nitroxides with Peroxyl Radicals and Its Relevance to Their Cytoprotective Properties. J Am Chem Soc 2018; 140:3798-3808. [PMID: 29451786 DOI: 10.1021/jacs.8b00998] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Sterically-hindered nitroxides such as 2,2,6,6-tetramethylpiperidin- N-oxyl (TEMPO) have long been ascribed antioxidant activity that is thought to underlie their chemopreventive and anti-aging properties. However, the most commonly invoked reactions in this context-combination with an alkyl radical to give a redox inactive alkoxyamine or catalysis of superoxide dismutation-are unlikely to be relevant under (most) physiological conditions. Herein, we characterize the kinetics and mechanisms of the reactions of TEMPO, as well as an N-arylnitroxide and an N, N-diarylnitroxide, with alkylperoxyl radicals, the propagating species in lipid peroxidation. In each of aqueous solution and lipid bilayers, they are found to be significantly more reactive than Vitamin E, Nature's premier radical-trapping antioxidant (RTA). Inhibited autoxidations of THF in aqueous buffers reveal that nitroxides reduce peroxyl radicals by electron transfer with rate constants ( k ≈ 106 to >107 M-1 s-1) that correlate with the standard potentials of the nitroxides ( E° ≈ 0.75-0.95 V vs NHE) and that this activity is catalytic in nitroxide. Regeneration of the nitroxide occurs by a two-step process involving hydride transfer from the substrate to the nitroxide-derived oxoammonium ion followed by H-atom transfer from the resultant hydroxylamine to a peroxyl radical. This reactivity extends from aqueous solution to phosphatidylcholine liposomes, where added NADPH can be used as a hydride donor to promote nitroxide recycling, as well as to cell culture, where the nitroxides are shown to be potent inhibitors of lipid peroxidation-associated cell death (ferroptosis). These insights have enabled the identification of the most potent nitroxide RTA and anti-ferroptotic agent yet described: phenoxazine- N-oxyl.
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Affiliation(s)
- Markus Griesser
- Department of Chemistry and Biomolecular Sciences , University of Ottawa , Ottawa , Ontario K1N 6N5 , Canada
| | - Ron Shah
- Department of Chemistry and Biomolecular Sciences , University of Ottawa , Ottawa , Ontario K1N 6N5 , Canada
| | - Antonius T Van Kessel
- Department of Chemistry and Biomolecular Sciences , University of Ottawa , Ottawa , Ontario K1N 6N5 , Canada
| | - Omkar Zilka
- Department of Chemistry and Biomolecular Sciences , University of Ottawa , Ottawa , Ontario K1N 6N5 , Canada
| | - Evan A Haidasz
- Department of Chemistry and Biomolecular Sciences , University of Ottawa , Ottawa , Ontario K1N 6N5 , Canada
| | - Derek A Pratt
- Department of Chemistry and Biomolecular Sciences , University of Ottawa , Ottawa , Ontario K1N 6N5 , Canada
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Baschieri A, Ajvazi MD, Tonfack JLF, Valgimigli L, Amorati R. Explaining the antioxidant activity of some common non-phenolic components of essential oils. Food Chem 2017; 232:656-663. [DOI: 10.1016/j.foodchem.2017.04.036] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Revised: 04/03/2017] [Accepted: 04/04/2017] [Indexed: 02/06/2023]
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42
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De Simone A, Bartolini M, Baschieri A, Apperley KYP, Chen HH, Guardigni M, Montanari S, Kobrlova T, Soukup O, Valgimigli L, Andrisano V, Keillor JW, Basso M, Milelli A. Hydroxy-substituted trans-cinnamoyl derivatives as multifunctional tools in the context of Alzheimer's disease. Eur J Med Chem 2017; 139:378-389. [PMID: 28810189 DOI: 10.1016/j.ejmech.2017.07.058] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 05/29/2017] [Accepted: 07/24/2017] [Indexed: 11/25/2022]
Abstract
Alzheimer's disease (AD) is a multifactorial pathology that requires multifaceted agents able to address its peculiar nature. In recent years, a plethora of proteins and biochemical pathways has been proposed as possible targets to counteract neurotoxicity. Although the complex scenario is not completely elucidated, close relationships are emerging among some of these actors. In particular, increasing evidence has shown that aggregation of amyloid beta (Aβ), glycogen synthase kinase 3β (GSK-3β) and oxidative stress are strictly interconnected and their concomitant modulation may have a positive and synergic effect in contrasting AD-related impairments. We designed compound 3 which demonstrated the ability to inhibit both GSK-3β (IC50 = 24.36 ± 0.01 μM) and Aβ42 self-aggregation (IC50 = 9.0 ± 1.4 μM), to chelate copper (II) and to act as exceptionally strong radical scavenger (kinh = 6.8 ± 0.5 · 105 M-1s-1) even in phosphate buffer at pH 7.4 (kinh = 3.2 ± 0.5 · 105 M-1s-1). Importantly, compound 3 showed high-predicted blood-brain barrier permeability, did not exert any significant cytotoxic effects in immature cortical neurons up to 50 μM and showed neuroprotective properties at micromolar concentration against toxic insult induced by glutamate.
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Affiliation(s)
- Angela De Simone
- Department for Life Quality Studies, Alma Mater Studiorum-University of Bologna, Corso d'Augusto 237, 47921 Rimini, Italy
| | - Manuela Bartolini
- Department of Pharmacy and Biotechnology, Alma Mater Studiorum-University of Bologna, Via Belmeloro 6, 40126 Bologna, Italy
| | - Andrea Baschieri
- Department of Chemistry "G. Ciamician", Alma Mater Studiorum-University of Bologna, Via S. Giacomo 11, 40126 Bologna, Italy
| | - Kim Y P Apperley
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, 10 Marie-Curie, Ottawa, ON, K1N 6N5, Canada
| | - Huan Huan Chen
- Department for Life Quality Studies, Alma Mater Studiorum-University of Bologna, Corso d'Augusto 237, 47921 Rimini, Italy
| | - Melissa Guardigni
- Department for Life Quality Studies, Alma Mater Studiorum-University of Bologna, Corso d'Augusto 237, 47921 Rimini, Italy
| | - Serena Montanari
- Department for Life Quality Studies, Alma Mater Studiorum-University of Bologna, Corso d'Augusto 237, 47921 Rimini, Italy
| | - Tereza Kobrlova
- Biomedical Research Center, University Hospital, Sokolska 581, 500 05 Hradec Kralove, Czech Republic
| | - Ondrej Soukup
- Biomedical Research Center, University Hospital, Sokolska 581, 500 05 Hradec Kralove, Czech Republic
| | - Luca Valgimigli
- Department of Chemistry "G. Ciamician", Alma Mater Studiorum-University of Bologna, Via S. Giacomo 11, 40126 Bologna, Italy
| | - Vincenza Andrisano
- Department for Life Quality Studies, Alma Mater Studiorum-University of Bologna, Corso d'Augusto 237, 47921 Rimini, Italy
| | - Jeffrey W Keillor
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, 10 Marie-Curie, Ottawa, ON, K1N 6N5, Canada
| | - Manuela Basso
- Laboratory of Transcriptional Neurobiology, Centre for Integrative Biology, University of Trento, Via Sommarive 9, 38123 Trento, Italy
| | - Andrea Milelli
- Department for Life Quality Studies, Alma Mater Studiorum-University of Bologna, Corso d'Augusto 237, 47921 Rimini, Italy.
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43
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Amorati R, Baschieri A, Cowden A, Valgimigli L. The Antioxidant Activity of Quercetin in Water Solution. Biomimetics (Basel) 2017; 2:E9. [PMID: 31105172 PMCID: PMC6352608 DOI: 10.3390/biomimetics2030009] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 06/19/2017] [Accepted: 06/22/2017] [Indexed: 01/11/2023] Open
Abstract
Despite its importance, little is known about the absolute performance and the mechanism for quercetin's antioxidant activity in water solution. We have investigated this aspect by combining differential oxygen-uptake kinetic measurements and B3LYP/6311+g (d,p) calculations. At pH = 2.1 (30 °C), quercetin had modest activity (kinh = 4.0 × 103 M-1 s-1), superimposable to catechol. On raising the pH to 7.4, reactivity was boosted 40-fold, trapping two peroxyl radicals in the chromen-4-one core and two in the catechol with kinh of 1.6 × 105 and 7.0 × 104 M-1 s-1. Reaction occurs from the equilibrating mono-anions in positions 4' and 7 and involves firstly the OH in position 3, having bond dissociation enthalpies of 75.0 and 78.7 kcal/mol, respectively, for the two anions. Reaction proceeds by a combination of proton-coupled electron-transfer mechanisms: electron⁻proton transfer (EPT) and sequential proton loss electron transfer (SPLET). Our results help rationalize quercetin's reactivity with peroxyl radicals and its importance under biomimetic settings, to act as a nutritional antioxidant.
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Affiliation(s)
- Riccardo Amorati
- University of Bologna, Department of Chemistry "G. Ciamician", Via S. Giacomo 11, 40126 Bologna, Italy.
| | - Andrea Baschieri
- University of Bologna, Department of Chemistry "G. Ciamician", Via S. Giacomo 11, 40126 Bologna, Italy.
| | - Adam Cowden
- School of Chemistry (Rm 267), University of Edinburgh, West Mains Road, Edinburgh EH9 3FJ, UK.
| | - Luca Valgimigli
- University of Bologna, Department of Chemistry "G. Ciamician", Via S. Giacomo 11, 40126 Bologna, Italy.
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Chauvin JPR, Griesser M, Pratt DA. Hydropersulfides: H-Atom Transfer Agents Par Excellence. J Am Chem Soc 2017; 139:6484-6493. [DOI: 10.1021/jacs.7b02571] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Jean-Philippe R. Chauvin
- Department of Chemistry and
Biomolecular Sciences, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada
| | - Markus Griesser
- Department of Chemistry and
Biomolecular Sciences, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada
| | - Derek A. Pratt
- Department of Chemistry and
Biomolecular Sciences, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada
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45
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Cartoni A, Catone D, Bolognesi P, Satta M, Markus P, Avaldi L. HSO2
+
Formation from Ion-Molecule Reactions of SO2
⋅+
with Water and Methane: Two Fast Reactions with Reverse Temperature-Dependent Kinetic Trend. Chemistry 2017; 23:6772-6780. [DOI: 10.1002/chem.201700028] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Indexed: 11/11/2022]
Affiliation(s)
- Antonella Cartoni
- Dipartimento di Chimica; Sapienza Università di Roma; Pl.e Aldo Moro 5 00185 Roma Italy
- Istituto di Struttura della Materia (ISM); Consiglio Nazionale delle Ricerche (CNR), Area della Ricerca di Roma 1; via Salaria Km 29,300 Monterotondo Scalo (RM) 00016 Italy
| | - Daniele Catone
- Istituto di Struttura della Materia (ISM); Consiglio Nazionale delle Ricerche (CNR), Area della Ricerca di Roma 2; via del Fosso del Cavaliere 10 00133 Roma Italy
| | - Paola Bolognesi
- Istituto di Struttura della Materia (ISM); Consiglio Nazionale delle Ricerche (CNR), Area della Ricerca di Roma 1; via Salaria Km 29,300 Monterotondo Scalo (RM) 00016 Italy
| | - Mauro Satta
- Istituto per lo Studio dei Materiali Nanostrutturati (ISMN); Dipartimento di Chimica; Sapienza Università di Roma; P.le Aldo Moro 5 00185 Roma Italy
| | - Pal Markus
- Istituto di Struttura della Materia (ISM); Consiglio Nazionale delle Ricerche (CNR), Area della Ricerca di Roma 1; via Salaria Km 29,300 Monterotondo Scalo (RM) 00016 Italy
| | - Lorenzo Avaldi
- Istituto di Struttura della Materia (ISM); Consiglio Nazionale delle Ricerche (CNR), Area della Ricerca di Roma 1; via Salaria Km 29,300 Monterotondo Scalo (RM) 00016 Italy
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46
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Amorati R, Valgimigli L, Viglianisi C, Schmallegger M, Neshchadin D, Gescheidt G. Proton-Coupled Electron Transfer from Hydrogen-Bonded Phenols to Benzophenone Triplets. Chemistry 2017; 23:5299-5306. [DOI: 10.1002/chem.201605931] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Indexed: 01/15/2023]
Affiliation(s)
- Riccardo Amorati
- University of Bologna; Department of Chemistry “G. Ciamician”; Via S. Giacomo 11 40126 Bologna Italy
| | - Luca Valgimigli
- University of Bologna; Department of Chemistry “G. Ciamician”; Via S. Giacomo 11 40126 Bologna Italy
| | - Caterina Viglianisi
- Department of Chemistry “Ugo Schiff”; University of Florence; Via della Lastruccia 3-13 50019 Sesto Fiorentino Italy
| | - Max Schmallegger
- Institute of Physical and Theoretical Chemistry; Graz University of Technology, NAWI Graz; Stremayrgasse 9 8010 Graz Austria
| | - Dmytro Neshchadin
- Institute of Physical and Theoretical Chemistry; Graz University of Technology, NAWI Graz; Stremayrgasse 9 8010 Graz Austria
| | - Georg Gescheidt
- Institute of Physical and Theoretical Chemistry; Graz University of Technology, NAWI Graz; Stremayrgasse 9 8010 Graz Austria
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47
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Affiliation(s)
- Muhammad Torequl Islam
- Postgraduate Program in Biotechnology, Northeast Biotechnology Network (RENORBIO), Federal University of Piauí, Teresina (Paiui), Brazil
- Department of Pharmacy, Southern University Bangladesh, Chittagong (Mehedibag), Bangladesh
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48
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Pérez-González A, Alvarez-Idaboy JR, Galano A. Dual antioxidant/pro-oxidant behavior of the tryptophan metabolite 3-hydroxyanthranilic acid: a theoretical investigation of reaction mechanisms and kinetics. NEW J CHEM 2017. [DOI: 10.1039/c6nj03980d] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Potent antioxidant in the absence of metal ions, responsible for the activity usually attributed to tryptophan. Pro-oxidant in the presence of metal ions; this effect increases with the pH.
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Affiliation(s)
| | - Juan Raúl Alvarez-Idaboy
- Facultad de Química
- Departamento de Física y Química Teórica
- Universidad Nacional Autónoma de México
- México DF 04510
- Mexico
| | - Annia Galano
- Departamento de Química
- Universidad Autónoma Metropolitana-Iztapalapa
- México D. F
- Mexico
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49
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Zheng Y, Wang J, Zhang J, Peng T, Li R. Syntheses of asymmetric zinc porphyrins bearing different pseudo-pyridine substituents and their photosensitization for visible-light-driven H2 production activity. Dalton Trans 2017; 46:8219-8228. [DOI: 10.1039/c7dt01029j] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Asymmetric zinc porphyrins bearing different pseudo-pyridine substituents were synthesized and used to sensitize Pt/g-C3N4 for photocatalytic H2 production.
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Affiliation(s)
- Ya Zheng
- College of Chemistry and Molecular Sciences
- Wuhan University
- Wuhan 430072
- P. R. China
| | - Jinming Wang
- College of Chemistry and Molecular Sciences
- Wuhan University
- Wuhan 430072
- P. R. China
| | - Jing Zhang
- College of Chemistry and Molecular Sciences
- Wuhan University
- Wuhan 430072
- P. R. China
| | - Tianyou Peng
- College of Chemistry and Molecular Sciences
- Wuhan University
- Wuhan 430072
- P. R. China
| | - Renjie Li
- College of Chemistry and Molecular Sciences
- Wuhan University
- Wuhan 430072
- P. R. China
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50
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Measuring Antioxidant Activity in Bioorganic Samples by the Differential Oxygen Uptake Apparatus: Recent Advances. J CHEM-NY 2017. [DOI: 10.1155/2017/6369358] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The measure of O2 consumption during the inhibited autoxidation of an easily oxidizable substrate is one of the most reliable and predictive methods to assess antioxidant activity, especially for structure-activity relationship studies, for food and industrial applications. The differential oxygen uptake apparatus described herein represents a powerful and cost-effective way to obtain antioxidant activity from inhibited autoxidation studies. These experiments provide the rate constant and the stoichiometry of the reaction between antioxidants and peroxyl radicals (ROO∙), which are involved in the propagation of radical damage. We show the operation principles and the utility of this instrumentation in the bioorganic laboratory, with regard to the recent advances in this field, ranging from the study of natural antioxidants in biomimetic system, to the use of substrates generating hydroperoxyl radicals, and to the evaluation of novel nanoantioxidants.
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