The Influence of Non-Covalent Complexation of ε-Viniferin on Its Antioxidant Activity: A Computational Investigation

We carefully selected a stable conformation of ε-viniferin as a representative model within the oligostilbene family to evaluate the influence of non-covalent association on its antioxidant activity, using Density Functional Theory (DFT). We calculated the Bond Dissociation Enthalpies (BDEs) in different positions and, in both gaseous and methanol phases. We noted that non-covalent complexation enhanced the antioxidant potential of ε-viniferin, particularly at positions where hydrogen bonding interactions are prevalent. Conversely, an increase in BDE values has been observed at positions where hydrogen bonding hinders effective electron donation, indicating reduced antioxidant activity upon complexation. We also found that positions that do not actively participate in hydrogen bonding within the complex maintain stable BDE values, preserving the antioxidant activity. Additionally, we explored the electro-molecular characteristics of ε-viniferin as single and complex forms. We found that non-covalent complexation has a limited impact on the molecule's electronic structure and reactivity. Our results emphasize the remarkable potential of non-covalent associations involving ε-viniferin as an enhanced antioxidant. This finding is anticipated to significantly contribute to the exploration and discovery of new, potent antioxidants.

Keywords:

ε-Viniferin , non-covalent complexation , Antioxidant Activity , Bond Dissociation Enthalpies , spin density distribution , Optoelectronic properties