Electrochemistry of 2,2‐Diphenyl‐1‐picrylhydrazyl (DPPH) in Acetonitrile in Presence of Ascorbic Acid ‐ Application for Antioxidant Properties Evaluation

Abstract

The electrochemistry of 2,2-diphenyl-1-picrylhydrazyl (DPPH) in acetonitrile was studied in presence of ascorbic acid (AAH 2 ) as model antioxidant. In the presence of AAH 2 , the intensities of the two characteristic systems of DPPH decreases and an intense oxidation peak at 1.07 V assigned to the oxidation of reduced DPPH was observed. The currents associated to these electrochemical processes showed excellent correlation with the amount of AAH 2 added and were used for determining its free radicals scavenger activity. Chronoamperometry was found more suitable for a real time monitoring of the chemical reaction between DPPH and an antioxidant, and thus to evaluate their efficiencies by determining the corresponding half-maximal inhibitory concentration (IC 50 ) values. Comparison of the reactivity of the antioxidants tested was possible by comparing the times necessary for the stabilization of the residual DPPH reduction currents. The method was subsequently applied to the evaluation of antioxidant properties of lemon and orange samples.[a] Dr.

Insights into the Antioxidant Mechanism of Newly Synthesized Benzoxazinic Nitrones: In Vitro and In Silico Studies with DPPH Model Radical

“…Moreover, in Figure 4 , the cyclic voltammogram of DPPH (D) shows a reversible one-electron oxidation and two reductions processes of the relatively stable DPPH radical, in agreement with previous literature reports [ 55 , 56 , 57 ], with half-wave potentials (E 1/2 ) of +0.76 V, +0.23 V, and −1.30 V, respectively. The voltametric features of the second reduction process reveal a sluggish electron transfer process.…”

Electrochemical Methods to Evaluate the Antioxidant Activity and Capacity of Foods: A Review

“…This leaded to a decrease of the anodic current, which was directly related to the concentration of antioxidants in the bulk solution [216]. A similar approach was later applied for the determination of the antioxidant activity of olive oils [217], antioxidant standards (gallic acid, ascorbic acid), and extracts from food samples (lemon and orange extract) [218], and the methods was also claimed very suitable for future advance of biomedicine [219].…”

Radical Scavenging Activity of Antioxidants by Cyclic Voltammetry

“…Deutchoua et al. used chronoamperometry to investigate the reaction of ascorbic acid with 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radicals [20]. Another study used voltammetry and coulometry to investigate antioxidants in human plasma [21], while Ivanova and colleagues proposed a potentiometry method to study the interaction of antioxidants with peroxyl radicals [22].…”