Insights into the HO· and HOO· radical scavenging activity of aryl carbamate derivative: a computational mechanistic and kinetic investigation

Aryl carbamates exhibit significant utility due to their diverse range of biological activities, including anticancer, antituberculosis, and antioxidant properties. This study will focus on a comparative evaluation of the antioxidant capabilities of two aryl carbamate derivatives, namely Methyl(Z)-(1-(hydroxyamino) ethyl)-5-(methoxycarbonyl) amino)-2-methyl-1H-indole 1 carboxylate (Compound 1) and Dimethyl (1,3-dioxo-2,3-dihydro-1H-indene-2,2-diyl) bis (4,1 phenylene) dicarbamate (Compound 2). To assess the anti-oxidant capacity, two distinct reactive oxygen species, such as highly reactive hydroxyl (HO·) and moderately reactive hydroperoxyl (HOO·), have been taken into consideration. Four distinct scavenging processes, including RAF, HAT, SETPT, and SPLET, have been investigated here. The RAF mechanism was determined to be the most effective anti-oxidant pathway, regardless of the compounds or free radicals investigated here. For both HO· and HOO·, compound 1 demonstrated more potent scavenging capabilities than compound 2. Compounds 1 and 2 react with the HO· radical very quickly due to its extraordinarily high reactivity; in contrast, the less reactive HOO· provides a rather moderate rate. The calculated values of overall rate constant of Comp. 1 reaction with HOO· are 3.7 × 103 M−1 s−1 (gas phase), 5.3 × 101 M−1 s−1 (water), and 3.6 × 100 M−1 s−1 (pentyl ethanoate). With this context it is clear both of the compounds can work as strong and mild antioxidant against HO· and HOO· radical, respectively.