engleski

Free radical scavenging activity of morin 2’-O− phenoxide anion

Due to intramolecular H-atom transfer deprotonation of the most acidic 3-OH group of morin yields 2’-O− phenoxide anion. The reaction enthalpies related to mechanisms of free radical scavenging activity of this dominant species at physiological pH of 7.4, were calculated by PM6 and DFT methods in gas-phase, water, benzene and DMSO. Obtained results indicate 4’-OH group of 2’-O− phenoxide anion as active site for radical inactivation. Thermodynamically favored mechanism depends on the polarity of reaction media: in polar solvents (water and DMSO) sequential proton loss electron transfer (SPLET) mechanism is preferred while in non-polar benzene (and in gas-phase) hydrogen atom transfer (HAT) mechanism is responsible for the free radical scavenging activity of morin phenoxide anion. Obtained results show that fast semiempirical PM6 method fairly mimics more accurate time consuming DFT results.

Morin ; Phenoxide anion ; Radical scavenging ; HAT ; SPLET ; SET-PT

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