An overview of the density functional theory on antioxidant bioactivity predictive feasibilities: Insights from natural antioxidant products.

• Antioxidant activity, a critical molecular characteristic, contributes to free-radical scavenging in the oxidatively-stressed biosystems and outside. • Natural and synthetic products antioxidant potentials are predicted through theoretically (DFT), and experimentally through use of DPPH, FRAP and ABTS-assays. • HOMO-LUMO, molecular-electrostatic-potential, hydrogen-transfer, single-electron-proton-transfers, sequential-proton-loss-electron-transfer, thermochemical parameters, i.e., free-energy change, enthalpy-change bond-dissociation enthalpy, proton-dissociation-enthalpy, ionization potential, proton-affinity, electron-transfer-enthalpy, inductive and resonance effects have been attributed towards contributing to the prediction of antioxidant activity. • Fundamentals and comparative have been drawn to validate the theoretical and experimental approach. Antioxidants play a crucial role in protecting biological systems from oxidative stress, which is implicated in a wide range of diseases. Computational methods have become increasingly valuable in studying the mechanisms of antioxidants, with density functional theory (DFT) being a popular approach. This review provides an overview of the theoretical basis of DFT and its application to molecular systems. It discusses the advantages and limitations of using DFT for studying antioxidants and explores the relationship between antioxidant activity and molecular structure. The paper also highlights the importance of solvation effects in determining antioxidant efficacy and suggests DFT-based methods for incorporating solvation effects into calculations. Case studies of specific antioxidants are presented to illustrate the role of the solvent environment in determining the antioxidant efficacy. Finally, it discusses the relationship between antioxidant activity and certain DFT parameters, and suggests future directions for research. Overall, this review provides valuable insights into the use of DFT in studying antioxidants, and sheds light on the future of computational studies in this field. [ABSTRACT FROM AUTHOR]