Vladimir Chobot1, Franz Hadacek. 1. Department of Chemical Ecology and Ecosystem Research, University of Vienna, Vienna, Austria. vladimir.chobot@univie.ac.at
Abstract
OBJECTIVES: Flavonoids are ubiquitous phenolic plant metabolites. Many of them are well known for their pro- and antioxidant properties. Myricetin has been reported to be either a potent antioxidant or a pro-oxidant depending on the conditions. The reaction conditions for the pro- and antioxidant activities were therefore investigated using variations of the deoxyribose degradation assay systems. METHODS: The deoxyribose degradation assay systems were conducted as follows; H(2)O(2)/Fe(III)/ascorbic acid, H(2)O(2)/Fe(III), Fe(III)/ascorbic acid, and Fe(III). Each system was carried out in two variants, FeCl(3) (iron ions added as FeCl(3)) and FeEDTA (iron added in complex with ethylenediaminetetraacetic acid). RESULTS: When ascorbic acid was present, myricetin showed antioxidant properties, especially when it occurred in complex with iron. In ascorbic acid-free systems, pro-oxidant activities prevailed, which where enhanced if iron was in complex with EDTA. DISCUSSION: Myricetin's antioxidant activity depends on both the reactive oxygen species (ROS) scavenging and iron ions chelation properties. The pro-oxidative properties are caused by reduction of molecular oxygen to ROS and iron(III) to iron(II). Myricetin is able to substitute for ascorbic acid albeit less efficiently.
OBJECTIVES:Flavonoids are ubiquitous phenolic plant metabolites. Many of them are well known for their pro- and antioxidant properties. Myricetin has been reported to be either a potent antioxidant or a pro-oxidant depending on the conditions. The reaction conditions for the pro- and antioxidant activities were therefore investigated using variations of the deoxyribose degradation assay systems. METHODS: The deoxyribose degradation assay systems were conducted as follows; H(2)O(2)/Fe(III)/ascorbic acid, H(2)O(2)/Fe(III), Fe(III)/ascorbic acid, and Fe(III). Each system was carried out in two variants, FeCl(3) (iron ions added as FeCl(3)) and FeEDTA (iron added in complex with ethylenediaminetetraacetic acid). RESULTS: When ascorbic acid was present, myricetin showed antioxidant properties, especially when it occurred in complex with iron. In ascorbic acid-free systems, pro-oxidant activities prevailed, which where enhanced if iron was in complex with EDTA. DISCUSSION: Myricetin's antioxidant activity depends on both the reactive oxygen species (ROS) scavenging and iron ions chelation properties. The pro-oxidative properties are caused by reduction of molecular oxygen to ROS and iron(III) to iron(II). Myricetin is able to substitute for ascorbic acid albeit less efficiently.
Authors: Rodrigo A Mendes; Shawan K C Almeida; Iuri N Soares; Cristina A Barboza; Renato G Freitas; Alex Brown; Gabriel L C de Souza Journal: J Mol Model Date: 2019-03-08 Impact factor: 1.810
Authors: Rodrigo A Mendes; Shawan K C Almeida; Iuri N Soares; Cristina A Barboza; Renato G Freitas; Alex Brown; Gabriel L C de Souza Journal: J Mol Model Date: 2018-05-11 Impact factor: 1.810
Authors: Marília F Manchope; Nayara A Artero; Victor Fattori; Sandra S Mizokami; Dimitrius L Pitol; João P M Issa; Sandra Y Fukada; Thiago M Cunha; José C Alves-Filho; Fernando Q Cunha; Rubia Casagrande; Waldiceu A Verri Journal: Inflamm Res Date: 2018-10-28 Impact factor: 4.575