Conceptual DFT study of antioxidant activity of carotenoids and its radicals

Here, we report the conceptual density functional theory reactivity indexes, electronegativity, hardness, and electrophilicity calculated from carotene molecules. Carotenoids are lipophilic pigments produced by plants with a sizeable conjugated polyene chain. Computational chemistry proposes two mechanisms of antioxidant activity: donating a hydrogen atom and donating an electron to the radical. The bond dissociation enthalpy characterizes the first mechanism, and ionization energy helps the analysis through the second mechanism. This article discusses the antioxidant activity of carotenoids and their radicals through conceptual density functional theory reactivity indexes, such as ionization energy, electronegativity, hardness, and electrophilicity. Graphics of molecular orbitals are also useful to explain the reactivity.