A density functional theory study of the reactivity descriptors and antioxidant behavior of Crocin

The molecular characteristics of Crocin (digentiobiosyl-8,8′-diapocarotene-8,8′-oate; C44H64O24), naturally occurring carotenoid pigment compound, such as: the ionization potential (I), electron affinity (A), electronegativity (χ), electrophicility (ω), and hardness have been calculated using Density Functional Theory (DFT) approach with B3LYP/6-31G(d,p) level of theory. The plots of Frontier Molecular Orbital and molecular electrostatic potential (MEP) for Crocin molecule along with the spin density distribution for its cation radical have been demonstrated. For the first time, we indicated the chemically active sites of the Crocin molecule by Fukui functions. Calculated components of polarizability tensor illustrate that sugar moiety in Crocin molecule has a vital role in its chemical reactivity. To conclude, our calculations are in accordance with the previous experimental reports (Papandreou et al. [5]) which reveal Crocin is an effective antioxidant and its gentiobiose terminals affect its antioxidant performance.