title: Antioxidant capacity of pure compounds and complex mixtures evaluated by the ORAC-pyrogallol red assay in the presence of Triton X-100 micelles.
abstract: The protective effect of different antioxidants and complex mixtures on the consumption of pyrogallol red (PGR) induced by peroxyl radicals was studied in the absence and presence of Triton X-100 micelles. The presence of micelles decreased significantly the protection of PGR afforded by lipophilic antioxidants (β-carotene, octyl gallate), while no effect of micelles was observed for hydrophilic antioxidants such as Trolox, caffeic acid, gallic acid, and ascorbic acid. In the presence of complex mixtures a clear effect of Triton X-100 micelles was also observed in the protection afforded by wines, tea infusions, and seed extracts of Eugenia jambolana and Myrciaria cauliflora. On the other hand, no effect of micelles was observed for orange juice and pulp fruit extracts. The ORAC (Oxygen Radical Absorbance Capacity) index was evaluated in the absence (ORAC-PGR) and presence of Triton X-100 micelles (ORAC-PGR(MIC)). Triton X-100 micelles affect ORAC-PGR values of antioxidants in a lipophilicity-dependent way. From the obtained results, we conclude that ORAC-PGR and ORAC-PGR(MIC) assays could be considered as an alternative to estimate the antioxidant ability (ORAC-PGR) and to infer the association to Triton X-100 micelles (ORAC-PGR/ORAC-PGR(MIC)) of pure antioxidants and their complex mixtures.
authors.affiliation: Departamento de Farmacia, Facultad de Química, Pontificia Universidad Católica de Chile, Santiago, Chile. msromero@uc.cl
authors.forename: Max
authors.initials: M
authors.lastname: Romero
authors.forename: Benjamin
authors.initials: B
authors.lastname: Rojano
authors.forename: Jaime
authors.initials: J
authors.lastname: Mella-Raipán
authors.forename: Carlos David
authors.initials: CD
authors.lastname: Pessoa-Mahana
authors.forename: Eduardo
authors.initials: E
authors.lastname: Lissi
authors.forename: Camilo
authors.initials: C
authors.lastname: López-Alarcón
mesh_terms: D000975:Antioxidants / Q000494:pharmacology*; D004396:Coloring Agents; D045424:Complex Mixtures; D057927:Hydrophobic and Hydrophilic Interactions; D008722:Methods; D008823:Micelles; D017830:Octoxynol; D011748:Pyrogallol / Q000031:analogs & derivatives* / Q000737:chemistry
chemical_list: D000975:Antioxidants; D004396:Coloring Agents; D045424:Complex Mixtures; D008823:Micelles; D011748:Pyrogallol; C058731:pyrogallol sulfonphthalein; D017830:Octoxynol