Zeppilli Davide, Pedergnana Veronica, Filippi Matteo, Orian Laura
Dipartimento di Scienze Chimiche, Università degli Studi di Padova, Via Marzolo 1, 35131 Padova, Italy.
Molecules. 2025 Mar 21;30(7):1408. doi: 10.3390/molecules30071408.
Phenolic compounds are important antioxidants with great ROS scavenging potential and the presence of the hydroxyl groups is fundamental for this chemical activity. Therefore, changing the chalcogen atom (oxygen) with any of its siblings of group 16 (sulfur, selenium and tellurium) may affect the reactivity of these compounds. In this work, the ROS scavenging activity and mechanism of phenyl chalcogenols was evaluated in silico, unravelling better performance with heavier chalcogens, both thermodynamically and kinetically. Furthermore, a scavenging mechanism switch is reported, moving from Concerted Proton Electron Transfer (CPET) in phenols to Hydrogen Atom Transfer (HAT) in the other phenyl chalcogenols. Both kinetic trends and mechanistic features are rationalized in the framework of Activation Strain Analysis (ASA). Lastly, the role of aromaticity is evidenced by analyzing the differences between the phenol/phenoxyl and methanol/methoxyl self-exchange reactions, as well as between the corresponding processes with the other chalcogens.
酚类化合物是重要的抗氧化剂，具有很强的活性氧清除潜力，羟基的存在是这种化学活性的基础。因此，用第16族的任何一个同族元素（硫、硒和碲）取代硫族原子（氧）可能会影响这些化合物的反应活性。在这项工作中，通过计算机模拟评估了苯基硫族醇的活性氧清除活性和机理，揭示了较重硫族元素在热力学和动力学方面具有更好的性能。此外，还报道了一种清除机理的转变，从酚类中的协同质子电子转移（CPET）转变为其他苯基硫族醇中的氢原子转移（HAT）。动力学趋势和机理特征在活化应变分析（ASA）框架内得到了合理的解释。最后，通过分析酚/酚氧基和甲醇/甲氧基自交换反应之间的差异，以及与其他硫族元素的相应过程之间的差异，证明了芳香性的作用。
