DIRECT SCAVENGING ACTIVITY OF 4,7-DIHYDROXYCOUMARIN DERIVATIVE TOWARDS SERIES OF CHLOROMETHYLPEROXY RADICALS

Abstract

In this study, the mechanisms of antiradical activity of the previously synthesized 4,7- dihydroxycoumarin derivative:(E)-3-(1-((4-hydroxyphenyl)amino)ethylidene)-2,4- dioxochroman-7-yl acetate (A-4OH) according to the series of chloromethylperoxy radicals: •OOCH2Cl (chloromethylperoxy), •OOCHCl2 (dichloromethylperoxy) and •OOCCl3 (trichloromethyl peroxy) were investigated. To assess the mechanisms of antiradical activity of A-4OH against chloromethylperoxy radicals, the following mechanistic pathways were examined: Hydrogen Atom Transfer (HAT), Single-Electron Transfer followed by Proton Transfer (SET-PT), and Radical Adduct Formation (RAF). The investigations were performed in water using sophisticated computational methods. The results of the study show that the activity against selected radicals decreases in series •OOCCl3 > •OOCHCl2 > •OOCH2Cl. The results of thermodynamic and kinetic parameters indicate that A-4OH inactivates selected radicals via the HAT mechanism.