Antioxidant Properties of Adrenaline in the Presence of Ge-132

G.E. Filonova (1) , E.N. Nikolaevskaya (1) , A.V. Kansuzyan (2) , I.V. Krylova (1) , M.P. Egorov (1) , V.V. Jouikov (2) , M.A. Syroeshkin (1)

1 RAS - Russian Academy of Sciences [Moscow]
2 ISCR - Institut des Sciences Chimiques de Rennes

Using cyclic voltammetry, UV and 1 H NMR spectroscopy, we have investigated the effect of 2-carboxyethylgermanium (Ge-132), the most common germanium-containing dietary supplement, on the antioxidant activity of adrenaline in aqueous solutions. The complex formed by adrenaline and Ge-132 is oxidizable at 400 mV more positive potentials compared to non-coordinated adrenaline which corresponds to its 9 kcal/mol more difficult oxidation. An equilibrium constant of the complex formation was estimated (1300 M-1). It was shown that at the concentrations <10-3 M the complex Ge-132-adrenaline is mostly dissociated to the initial compounds, and the influence of Ge-132 on the antioxidant properties of adrenaline becomes significant only when the former is in an excess. Considering that such concentrations are typical for physiological conditions, this fact can be significant in identifying the mechanism of the biological action of Ge-132 and its interference with the biological catechols.

Keywords: Adrenaline; Antioxidants; Cyclic voltammetry; NMR spectroscopy; Germanium

Domains: Chemical Sciences

G.E. Filonova, E.N. Nikolaevskaya, A.V. Kansuzyan, I.V. Krylova, M.P. Egorov, et al.. Antioxidant Properties of Adrenaline in the Presence of Ge-132. European Journal of Organic Chemistry, 2019, 2019 (26), pp.4128-4132. ⟨10.1002/ejoc.201900331⟩. ⟨hal-02181834⟩