Influence of cis–trans isomerization induced by photoexcitation on the antioxidant properties of piceatannol and its derivatives

Abstract

In recent years, free radicals have been identified as key contributors to various diseases, with UV irradiation significantly accelerating their proliferation. Consequently, the search for molecules with enhanced antiradical properties under photoexcitation has become urgent. Notably, we are pioneering the use of molecules with unique photoisomerization reactions to initiate a new chapter in the development of novel antioxidants. Herein, this study examines the influence of cis–trans isomerization induced by photoexcitation on the antioxidant properties of piceatannol and its derivatives. Using systematic quantum chemistry calculation methods, we assessed thermodynamic parameters, ionization potential, frontier molecular orbitals, and global descriptive parameters to simulate their antioxidant capabilities in the cis- and trans-forms at the S₀ and S₁ states. Thermodynamic analysis revealed that among the candidate molecules, the hydrogen atom transfer (HAT) mechanism is the most favorable reaction pathway. Thrillingly, we found that the photoexcitation can enhance the antioxidant activity of the studied molecules. Remarkably, in contrast to the S₀ state, cis-structures exhibit superior antioxidant properties in the S₁ state. On the whole, our findings would provide new insights and theoretical guidance for the development of antioxidant molecules.