On the Electrochemical Oxidation of Resveratrol

Abstract

Resveratrol (3,5,4'-trihydroxystilbene) is an organic metabolite produced by plants in response to fungal infection. It is found in various plant fruits and is abundant in the skins of unripe grapes and related products. This photosensitive molecule exists in two isomeric forms, trans and cis-resveratrol. The antioxidant activity of resveratrol, both trans and cis forms, was evaluated by means of cyclic, differential pulse and square-wave voltammetry over a wide pH range, using a glassy carbon electrode. Voltammograms of resveratrol presented two oxidation peaks; the first oxidation peak corresponds to the oxidation of the phenol group and was shown to undergo an irreversible oxidation reaction. The second oxidation peak corresponds to the oxidation of the resorcinol moiety and is also irreversible. The influence of pH on the electrochemical oxidation process of resveratrol was investigated.

Electrochemical Detection of Amyloid-Beta Aggregation in the Presence of Resveratrol

“…The presence of small molecule inhibitors and accelerators of Aβ aggregation have also been monitored using voltammetry. [42][43][44] As reported by several groups, [42][43][44][45][46] the innate tyrosine residue found in both Aβ 40 and Aβ 42 , displayed an oxidation potential around 0.75 V vs. Ag/AgCl. 42,44,47 Therefore, the aggregation process of Aβ could be traced by the tyrosine oxidation peak over time.…”

“…Aβ 40 aggregation in the presence of resveratrol.-EIS measurements were performed using oligomer-modified electrodes that were incubated with solutions of 50 μM Aβ 40 , 50 μM resveratrol and 50 μM Aβ 40 with 50 μM resveratrol. A schematic of the Au electrode preparation process is displayed in Figure 1.…”

“…[1][2][3][4] Pathological hallmarks of AD include the accumulation of senile plaques and neurofibrillary tangles in the brain, both of which have been associated with neuronal death. The major constituents of these plaques have been found to be amyloid-β (Aβ), with the most abundant isoforms being amyloid-β 1-40 (Aβ 40 ) and amyloid-β 1-42 (Aβ 42 ). [5][6][7] A characteristic feature of Aβ is their propensity to aggregate and form toxic species over time.…”

“…Incubation with Aβ 40 and EIS measurements.-Incubating solutions of 50 μM Aβ 40 and 50 μM resveratrol, or 50 μM Aβ 40 alone, or 50 μM resveratrol alone were aliquoted at 100 μL volumes into separate micro-centrifuge tubes and incubated with the modified Au electrodes (one electrode per tube) at 37…”

Solid State Electrochemical Behavior of Usnic Acid at a Glassy Carbon Electrode

“…Solid state electroanalysis has become an important step in the direct analysis of well defined solid powders without further pretreatment or time-consuming deposition procedures (Grygar et al 2002), and has been used to study the electrochemistry of a variety of insoluble solid compounds (Scholz and Meyer 1994;Janeiro and Oliveira-Brett 2005;Corduneanu, Janeiro, and Oliveira-Brett 2006).…”