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Bencze F, Bognár B, Kálai T, Kollár L, Nagymihály Z, Kunsági-Máté S. A New Application of Spin and Fluorescence Double-Sensor Molecules. Molecules 2023; 28:molecules28072978. [PMID: 37049741 PMCID: PMC10096054 DOI: 10.3390/molecules28072978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 03/24/2023] [Accepted: 03/25/2023] [Indexed: 03/29/2023] Open
Abstract
EPR imaging techniques are known to be successful tools for mapping living bodies, especially because of the high transparency of tissues in the microwave range. This technique assumes the presence of radicals whose in vivo transport is also controlled by serum albumins. Accordingly, in this study, the interactions between 3-hydroxymethyl-1-oxyl-4-(pyren-1-yl)-2,2,5,5-tetramethyl-2,5-dihydro-1H-pyrrole radical and the human serum albumin molecules were investigated. To clarify the adsorption processes of this radical onto the surface of human serum albumin (HSA), the interaction of the OMe derivative of the radical was also examined parallel with the studies on the radical—HSA interactions. Considering the solubility issues and also to modulate the transport, inclusion complexes of the radical with a cavitand derivative were also studied. The latter interactions were observed through fluorescence spectroscopy, fluorescence polarization, and by EPR spectroscopy. As a double-sensor molecule, we found that the fluorophore nitroxide is a good candidate as it gave further information about host-guest interactions (fluorescence, fluorescence polarization, and EPR). We also found that in the presence of a cavitand, a complex with greater stability was formed between the sensor molecule and the human serum albumin. Based on these observations, we can conclude that applying this double-sensor (spin, fluorescent) molecule is useful in cases when different interactions can affect the EPR measurements.
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Affiliation(s)
- Flórián Bencze
- Department of Organic and Medicinal Chemistry, Faculty of Pharmacy, University of Pécs, Honvéd Street 1, H-7624 Pécs, Hungary
| | - Balázs Bognár
- Department of Organic and Medicinal Chemistry, Faculty of Pharmacy, University of Pécs, Honvéd Street 1, H-7624 Pécs, Hungary
| | - Tamás Kálai
- Department of Organic and Medicinal Chemistry, Faculty of Pharmacy, University of Pécs, Honvéd Street 1, H-7624 Pécs, Hungary
- János Szentágothai Research Center, University of Pécs, Ifjúság útja 20, H-7624 Pécs, Hungary
| | - László Kollár
- János Szentágothai Research Center, University of Pécs, Ifjúság útja 20, H-7624 Pécs, Hungary
- ELKH-PTE Research Group for Selective Syntheses, Ifjúság útja 6, H-7624 Pécs, Hungary
| | - Zoltán Nagymihály
- János Szentágothai Research Center, University of Pécs, Ifjúság útja 20, H-7624 Pécs, Hungary
| | - Sandor Kunsági-Máté
- Department of Organic and Medicinal Chemistry, Faculty of Pharmacy, University of Pécs, Honvéd Street 1, H-7624 Pécs, Hungary
- János Szentágothai Research Center, University of Pécs, Ifjúság útja 20, H-7624 Pécs, Hungary
- Department of Physical Chemistry and Materials Science, Faculty of Sciences, University of Pécs, Ifjúság 6, H-7624 Pécs, Hungary
- Correspondence:
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Różanowska MB, Pawlak A, Różanowski B. Products of Docosahexaenoate Oxidation as Contributors to Photosensitising Properties of Retinal Lipofuscin. Int J Mol Sci 2021; 22:ijms22073525. [PMID: 33805370 PMCID: PMC8037991 DOI: 10.3390/ijms22073525] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 03/24/2021] [Accepted: 03/25/2021] [Indexed: 12/16/2022] Open
Abstract
Retinal lipofuscin which accumulates with age in the retinal pigment epithelium (RPE) is subjected to daily exposures to high fluxes of visible light and exhibits potent photosensitising properties; however, the molecules responsible for its photoreactivity remain unknown. Here, we demonstrate that autooxidation of docosahexaenoate (DHE) leads to the formation of products absorbing, in addition to UVB and UVA light, also visible light. The products of DHE oxidation exhibit potent photosensitising properties similar to photosensitising properties of lipofuscin, including generation of an excited triplet state with similar characteristics as the lipofuscin triplet state, and photosensitised formation of singlet oxygen and superoxide. The quantum yields of singlet oxygen and superoxide generation by oxidised DHE photoexcited with visible light are 2.4- and 3.6-fold higher, respectively, than for lipofuscin, which is consistent with the fact that lipofuscin contains some chromophores which do contribute to the absorption of light but not so much to its photosensitising properties. Importantly, the wavelength dependence of photooxidation induced by DHE oxidation products normalised to equal numbers of incident photons is also similar to that of lipofuscin—it steeply increases with decreasing wavelength. Altogether, our results demonstrate that products of DHE oxidation include potent photosensitiser(s) which are likely to contribute to lipofuscin photoreactivity.
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Affiliation(s)
- Małgorzata B. Różanowska
- School of Optometry and Vision Sciences, Cardiff University, Cardiff CF24 4HQ, Wales, UK
- Cardiff Institute for Tissue Engineering and Repair (CITER), Cardiff University, Cardiff CF24 4HQ, Wales, UK
- Correspondence: ; Tel.: +44-292087-5057
| | - Anna Pawlak
- Department of Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland;
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Mravljak J, Ojsteršek T, Pajk S, Sollner Dolenc M. Coumarin-based dual fluorescent spin-probes. Tetrahedron Lett 2013. [DOI: 10.1016/j.tetlet.2013.07.084] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Yan GP, Fairfull-Smith KE, Smith CD, Hanson GR, Bottle SE. Porphyrin containing isoindoline nitroxides as potential fluorescence sensors of free radicals. J PORPHYR PHTHALOCYA 2012. [DOI: 10.1142/s1088424611003203] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
A series of new spin-labeled porphyrin containing isoindoline nitroxide moieties were synthesized and characterized as potential free radical fluorescence sensors. Fluorescence-suppression was observed in the free-base monoradical porphyrins, whilst the free-base biradical porphyrins exhibited highly suppressed fluorescence about three times greater than the monoradical porphyrins. The observed fluorescence-suppression was attributed to enhanced intersystem crossing resulting from electronexchange between the doublet nitroxide and the excited porphyrin fluorophore. Notably, fluorescencesuppression was not as strong in the related metalated porphyrins, possibly due to insufficient spin coupling between the nitroxide and the porphyrin. Continuous wave EPR spectroscopy of the diradical porphyrins in fluid solution suggests that the nitroxyl-nitroxyl interspin distance is long enough and tumbling is fast enough not to detect dipolar coupling.
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Affiliation(s)
- Guo-Ping Yan
- School of Material Science and Engineering, Wuhan Institute of Technology, Wuhan 430073, P.R. China
- ARC Centre of Excellence for Free Radical Chemistry and Biotechnology, Chemistry Discipline, Faculty of Science and Technology, Queensland University of Technology, Brisbane, QLD 4001, Australia
| | - Kathryn E. Fairfull-Smith
- ARC Centre of Excellence for Free Radical Chemistry and Biotechnology, Chemistry Discipline, Faculty of Science and Technology, Queensland University of Technology, Brisbane, QLD 4001, Australia
| | - Craig D. Smith
- ARC Centre of Excellence for Free Radical Chemistry and Biotechnology, Chemistry Discipline, Faculty of Science and Technology, Queensland University of Technology, Brisbane, QLD 4001, Australia
| | - Graeme R. Hanson
- Centre for Advanced Imaging, The University of Queensland, St. Lucia, QLD 4072, Australia
| | - Steven E. Bottle
- ARC Centre of Excellence for Free Radical Chemistry and Biotechnology, Chemistry Discipline, Faculty of Science and Technology, Queensland University of Technology, Brisbane, QLD 4001, Australia
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Morris JC, McMurtrie JC, Bottle SE, Fairfull-Smith KE. Generation of Profluorescent Isoindoline Nitroxides Using Click Chemistry. J Org Chem 2011; 76:4964-72. [DOI: 10.1021/jo200613r] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Jason C. Morris
- ARC Centre of Excellence for Free Radical Chemistry and Biotechnology and ‡Chemistry Discipline, Faculty of Science and Technology, Queensland University of Technology, Queensland 4001, Australia
| | - John C. McMurtrie
- ARC Centre of Excellence for Free Radical Chemistry and Biotechnology and ‡Chemistry Discipline, Faculty of Science and Technology, Queensland University of Technology, Queensland 4001, Australia
| | - Steven E. Bottle
- ARC Centre of Excellence for Free Radical Chemistry and Biotechnology and ‡Chemistry Discipline, Faculty of Science and Technology, Queensland University of Technology, Queensland 4001, Australia
| | - Kathryn E. Fairfull-Smith
- ARC Centre of Excellence for Free Radical Chemistry and Biotechnology and ‡Chemistry Discipline, Faculty of Science and Technology, Queensland University of Technology, Queensland 4001, Australia
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Pajk S, Garvas M, Štrancar J, Pečar S. Nitroxide–fluorophore double probes: a potential tool for studying membrane heterogeneity by ESR and fluorescence. Org Biomol Chem 2011; 9:4150-9. [DOI: 10.1039/c0ob01173h] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Hideg E, Kálai T, Hideg K. Direct detection of free radicals and reactive oxygen species in thylakoids. Methods Mol Biol 2011; 684:187-200. [PMID: 20960131 DOI: 10.1007/978-1-60761-925-3_16] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
In plants, reactive oxygen species (ROS), also known as active oxygen species (AOS), are associated with normal, physiologic processes as well as with responses to adverse conditions. ROS are connected to stress in many ways: as primary elicitors, as products and propagators of oxidative damage, or as signal molecules initiating defense or adaptation. The photosynthetic electron transport is a major site of oxidative stress by visible or ultraviolet light, high or low temperature, pollutants or herbicides. ROS production can be presumed from detecting oxidatively damaged lipids, proteins, or pigments as well as from the alleviating effects of added antioxidants. On the contrary, measuring ROS by special sensor molecules provides more direct information. This chapter focuses on the application of spin trapping electron paramagnetic resonance (EPR) spectroscopy for detecting ROS: singlet oxygen and oxygen free radicals in thylakoid membrane preparations.
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Affiliation(s)
- Eva Hideg
- Institute of Plant Biology, Biological Research Center, Hungarian Academy of Sciences, Szeged, Hungary,
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Wang J, Dang V, Zhao W, Lu D, Rivera BK, Villamena FA, Wang PG, Kuppusamy P. Perchlorotrityl radical-fluorophore conjugates as dual fluorescence and EPR probes for superoxide radical anion. Bioorg Med Chem 2009; 18:922-9. [PMID: 19963389 DOI: 10.1016/j.bmc.2009.11.034] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2009] [Revised: 11/11/2009] [Accepted: 11/14/2009] [Indexed: 11/24/2022]
Abstract
Perchlorotrityl radicals, mono-substituted with a fluorophore using an amide linker of varying chain length, were synthesized and characterized. Electron paramagnetic resonance (EPR) spectroscopic study indicated free-electron coupling with the aromatic hydrogen nuclei and long-range coupling with the methylene hydrogens of the linker group. Reactivity of the fluorophore-conjugated trityls with superoxide radical anion showed quenching of EPR signal and enhancement of fluorescence emission spectrum. This work presents the first example of a perchlorotrityl-fluorophore conjugate that can potentially be employed as a dual probe for the detection of superoxide under oxidative stress-mediated conditions in biological systems.
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Affiliation(s)
- Jinhua Wang
- Davis Heart and Lung Research Institute, Department of Chemistry, The Ohio State University, Columbus, OH 43210, USA
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Fairfull-Smith KE, Bottle SE. The Synthesis and Physical Properties of Novel Polyaromatic Profluorescent Isoindoline Nitroxide Probes. European J Org Chem 2008. [DOI: 10.1002/ejoc.200800597] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Han SK, Bilski P, Karriker B, Sik RH, Chignell CF. Oxidation of flame retardant tetrabromobisphenol A by singlet oxygen. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2008; 42:166-72. [PMID: 18350892 PMCID: PMC2376276 DOI: 10.1021/es071800d] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Wide use of flame retardants can pose an environmental hazard, and it is of interest to investigate how they may degrade. We report here that 3,3',5,5'-tetrabromobisphenol A (TBBPA) is subject to photosensitized oxidation involving singlet molecular oxygen ((1)O2). By using visible light and rose bengal or methylene blue as 102 photosensitizers, we have found that TBBPA is a 102 quencher. The quenching rate constant, k(q), depends on TBBPA ionization (pK = 7.4). In acetonitrile, where TBBPA is undissociated, the kq value is 6.1 x 10(5) M(-1) s(-1) for a TBBPA monomer and decreases to 2.9 x 10(4) M(-1) s(-1) for TBBPA dimers and/or aggregates. TBBPA dissociates in aqueous solutions, and its kq value is 1.44 x 10(9) M(-1) s(-1) in alkaline solution, decreasing to 3.9 x 10(8) M(-1) s(-1) at pH 7.2. The strong 102 quenching by TBBPA anion initiates an efficient oxidation of TBBPA, which results in oxygen consumption in aqueous micellar (e.g., Triton X-100) solutions containing photosensitizer. This oxygen consumption is mediated by transient radical species, which we detected by using EPR spectroscopy. We observed two major radicals and one minor radical generated from TBBPA by reaction with 102 at pH 10. One was identified as the 2,6-dibromo-p-benzosemiquinone radical (a2H = 2.36 G, g = 2.0056). A second radical (aH = 2.10 G, g = 2.0055) could not be identified butwas probably a 2,6-dibromo-p-benzosemiquinone radical containing an EPR-silent substituent at the 3-position. Spin trapping with 5,5-dimethyl-1-pyrroline N-oxide (DPMO) showed that other minor radicals (hydroxyl, carbon-centered) are also generated during the reaction of TBBPA with (1)O2. The photosensitized production of radicals and oxygen consumption were completely inhibited by the azide anion, an efficient physical (1)O2 quencher. Because TBBPA is a stable compound that at neutral pH does not absorb much of the atmosphere-filtered solar radiation, its photosensitized oxidation by (1)O2 may be the key reaction initiating or mediating TBBPA degradation in the natural environment.
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Affiliation(s)
- S K Han
- Department of Marine Environmental Engineering, Mokpo National Maritime University, 571-2 Chukkyo-dong, Mokpo 530-729, South Korea
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Bognár B, Øz E, Hideg K, Kálai T. Synthesis of new double (spin and fluorescence) sensor reagents and labels. J Heterocycl Chem 2006. [DOI: 10.1002/jhet.5570430113] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Keddie DJ, Johnson TE, Arnold DP, Bottle SE. Synthesis of profluorescent isoindoline nitroxides via palladium-catalysed Heck alkenylation. Org Biomol Chem 2005; 3:2593-8. [PMID: 15999192 DOI: 10.1039/b504354a] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The synthesis of a new structural class of isoindoline nitroxides (aminoxyls), accessible via the palladium-catalysed Heck reaction, is presented. Reaction of the aryl bromoamine, 5-bromo-1,1,3,3-tetramethylisoindoline (4) or dibromoamine, 5,6-dibromo-1,1,3,3-tetramethylisoindoline (5) or the analogous bromonitroxides 6 and 7 with methyl acrylate gives the acrylate substituted tetramethylisoindoline amines 8 and 10 and nitroxides 12 and 14. Similarly, the reaction of the aryl bromides and dibromides 4-7 with methyl 4-vinylbenzoate gives the carboxystyryl substituted tetramethylisoindoline amines 9 and 11 and the analogous nitroxides 13 and 15. The carboxystyryl tetramethylisoindoline nitroxides demonstrate strongly suppressed fluorescence, which is revealed upon removal of the free radical by reduction or radical coupling.
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Affiliation(s)
- Daniel J Keddie
- School of Physical and Chemical Sciences, Queensland University of Technology, GPO Box 2434, Q4001 Australia
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