Electrochemical analysis of the properties of benzene-1,2,4-triol
1,2,4-benzenetriol is an aromatic chemical compound used in direct hair colouring products at a maximum use concentration of 3.0%. In plants it can be found as a product of the degradation of some organic compounds, while in humans it can be detected after poisoning with benzene because it is a metabolite of the biotransformation of benzene. In the human organism, 1,2,4-benzenetriol causes harmful effects such as DNA damage and there is possibility that 1,2,4-benzenetriol-induced DNA damage is one of the primary reactions in carcinogenesis induced by benzene. In nature, this compound is found in coffee extracts inhibiting the anti-hypertensive effect of chlorogenic acid. Hydroxyhydroquinone or 1,2,4-benzenetriol (BT) detected in the beverages has a structure that coincides with the water-soluble form of a sesame lignan, sesamol and further studies are required to confirm the importance of the cellular antioxidant activity of BT.
Materials and methods: In this study we examined the electrochemical properties of 1,2,4-benzenetriol by using cyclic voltammetry and square-wave voltammetry. Cyclic voltammetry (CV) is widely used for the study of redox processes, for understanding the reaction mechanisms, and for obtaining stability of reaction products.
To perform this study, we used a three-electrode system, graphite rod was used as a working electrode, the reference electrode was silver / silver chloride (Ag / AgCl), while the auxiliary electrode was Pt-electrode.
Results: The electrochemical response of the aqueous solution of 1,2,4-benzenetriol at different pH (3 to 9) depends mainly on pH. The calculated diffusion coefficient indicates that the process of diffusion of this substance is relatively low. The complexes between benzenetriol the Fe2+ and Mg2+ ions are the type 1:1 (one ligand and one metal ion are complexed). The values of the stability constants show that the complex of magnesium ions and benzenetriol is weak, while the complex with iron ions is moderately stable complex. In strong alkaline environment there is a chemical transformation and it is assumed that the new compound has four OH groups. For examination of the anti-oxidative potential we compared the native 1,2,4-benzenetriol, re-titrated benzentriol and vitamin C using ABTS. It has been confirmed that the tetra-hydroxy compound has the highest antioxidant potential.
Conclusion: The results obtained of the study will help in further investigations of antioxidant properties of 1,2,4-benzenetriol and the potential use of this compound as an antioxidant.
Keywords: 1,2,4-benzentriol, Anti-oxidative potential, Cyclic voltammetry, Complexes with metal ions.