o:28941 Antioxidative activity of caffeic acid – mechanistic DFT study en Abstract: This paper reports the results of comprehensive mechanistic investigations of the hydrogen atom transfer (HAT), radical adduct formation (RAF), single electron transfer – proton transfer (SET-PT), and sequential proton loss electron transfer (SPLET) mechanisms of caffeic acid (CA). The goals of the work were achieved by simulating the reactions of CA with hydroxyl radical in benzene and water solutions. It was found that SET-PT is not a favourable antioxidative mechanism of CA. On the other hand, HAT and RAF are competitive, because HAT pathways yield thermodynamically more stable radical products, and RAF pathways require smaller activation barriers. In polar basic environment SPLET is a probable antioxidative mechanism of CA, with exceptionally large rate. Keywords: activation energies, reaction energies, rate constants, M06-2X/6-311++G(d,p) theoretical model, CPCM solvation model 1552099 10.5937/KgJSci1739109R 1552101 1450-9636 2023-04-26T07:10:01.273Z 44 no 46 Izudin Redžepović Državni univerzitet u Novom Pazaru 0000-0003-4956-0407 Svetlana Marković person Jelena Tošović person application/pdf 566730 https://phaidrabg.bg.ac.rs/o:28941 no yes 1 70 92000001 20A01 Kragujevac Journal of Science 39 109 122 2017