A DFT study on the mechanism and kinetics of reactions of pterostilbene with hydroxyl and hydroperoxyl radicals

The mechanism and kinetics of pterostilbene reactions with (OH)-O-center dot and (OOH)-O-center dot radicals were studied in gas and aqueous phases through Density Functional Theory (DFT). For the pterostilbene +(OH)-O-center dot reaction in gas phase, the addition of (OH)-O-center dot to unsaturated carbons is kinetically favored with respect to the direct hydrogen-abstraction from the hydroxyl group. In aqueous solution,(OH)-O-center dot should react at diffusion controlled rate with pterostilbene via hydrogen abstraction or adduct formation. For pterostilbene +(OOH)-O-center dot reaction in gas phase, the highest rate constant was obtained for hydrogen abstraction pathway in the hydroxyl group. In solution, only the hydrogen-abstraction mechanism is thermodynamically favored. (C) 2015 Elsevier B.V. All rights reserved.