Development of a Singlet Oxygen Absorption Capacity (SOAC) Assay Method. Measurements of the SOAC Values for Carotenoids and α-Tocopherol in an Aqueous Triton X-100 Micellar Solution
| Autor: | Nagao Azuma, Kazuo Mukai, Shingo Takahashi, Aya Ouchi, Koichi Aizawa, Shin-ichi Nagaoka |
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| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
Absorption spectroscopy Octoxynol alpha-Tocopherol Analytical chemistry Photochemistry Fluorescence spectroscopy Antioxidants 03 medical and health sciences chemistry.chemical_compound Micelles 030109 nutrition & dietetics Aqueous solution Chloroform Spectroscopy Near-Infrared Singlet Oxygen Singlet oxygen General Chemistry Carotenoids Solvent Kinetics 030104 developmental biology chemistry Micellar solutions Triton X-100 General Agricultural and Biological Sciences |
| Zdroj: | Journal of agricultural and food chemistry. 65(4) |
| ISSN: | 1520-5118 |
| Popis: | Recently, a new assay method for the quantification of the singlet oxygen absorption capacity (SOAC) of antioxidants (AOs) and food extracts in homogeneous organic solvents was proposed. In this study, second-order rate constants (kQ) for the reaction of singlet oxygen (1O2) with eight different carotenoids (Cars) and α-tocopherol (α-Toc) were measured in an aqueous Triton X-100 (5.0 wt %) micellar solution (pH 7.4, 35 °C), which was used as a simple model of biomembranes. The kQ and relative SOAC values were measured using ultraviolet–visible (UV–vis) spectroscopy. The UV–vis absorption spectra of Cars and α-Toc were measured in both a micellar solution and chloroform, to investigate the effect of solvent on the kQ and SOAC values. Furthermore, decay rates (kd) of 1O2 were measured in 0.0, 1.0, 3.0, and 5.0 wt % micellar solutions (pH 7.4), using time-resolved near-infrared fluorescence spectroscopy, to determine the absolute kQ values of the AOs. The results obtained demonstrate that the kQ values of AO... |
| Databáze: | OpenAIRE |
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