Sensitized photo-oxidation of gadusol species mediated by singlet oxygen
| Autor: | Dalila E. Orallo, Sonia G. Bertolotti, Nayla Jimena Lores, Ernesto Maximiliano Arbeloa, María Sandra Churio |
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| Rok vydání: | 2020 |
| Předmět: |
Double bond
Ultraviolet Rays Biophysics Photochemistry Antioxidants Mass Spectrometry chemistry.chemical_compound Reaction rate constant Molecule Radiology Nuclear Medicine and imaging Micelles Fluorescent Dyes chemistry.chemical_classification Radiation Aqueous solution Quenching (fluorescence) Photolysis Radiological and Ultrasound Technology Singlet Oxygen Singlet oxygen Cyclohexanols Enol Oxygen Kinetics Spectrometry Fluorescence chemistry Models Chemical Phosphorescence Oxidation-Reduction |
| Zdroj: | Journal of photochemistry and photobiology. B, Biology. 213 |
| ISSN: | 1873-2682 |
| Popis: | Gadusols are efficient nature UV sunscreens with antioxidant capacity. The kinetics of the quenching reactions of singlet oxygen O2(1∆g) by gadusol species was evaluated in aqueous solution as well as in the presence of direct charged micelles. Time-resolved phosphorescence detection of O2(1∆g) indicated that gadusolate, the main species under biological pH, is a more efficient quencher than the enol form with a rate constant of ca. 1.3 × 108 L mol−1 s−1. The deactivation proceeds via a collisional mechanism with clear dominance of chemical pathways, according to the rates of gadusol and oxygen consumptions, and typical photooxidation quantum yields of ca. 7%. The relative contributions of the chemical and physical quenching steps were not affected by the presence of anionic or cationic micelles emulating simple pseudo-biological environments. The products of the photo-oxidative quenching support a type II mechanism initiated by the addition of O2(1∆g) to the C-C double bond of gadusolate. These results point to the relevance of considering the role of sacrifice antioxidant along with the UV-screening function for gadusol, particularly in the context of potential biotechnological applications of this natural molecule. |
| Databáze: | OpenAIRE |
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