Shang, Ya-Jing; Qian, Yi-Ping; Liu, Xiao-Da; Dai, Fang; Shang, Xian-Ling; Jia, Wen-Qiang; Liu, Qiang; Fang, Jian-Guo; Zhou, Bo published the artcile< Radical-Scavenging Activity and Mechanism of Resveratrol-Oriented Analogues: Influence of the Solvent, Radical, and Substitution>, Related Products of 112-63-0, the main research area is radical scavenging resveratrol oriented analog solvent substitution.
Resveratrol (3,5,4′-trihydroxy-trans-stilbene, 3,5,4′-THS) is a known natural antioxidant and cancer chemopreventive agent that has attracted much interest in the past decade. To find a more active antioxidant and study the antioxidative mechanism with resveratrol as the lead compound, the authors synthesized 3,5-dihydroxy-trans-stilbene (3,5-DHS), 4-hydroxy-trans-stilbene (4-HS) 3,4-dihydroxy-trans-stilbene (3,4-DHS), 4,4′-dihydroxy-trans-stilbene (4,4′-DHS), 4-hydroxy-3-methoxy-trans-stilbene (3-MeO-4-HS), 4-hydroxy-4′-methoxy-trans-stilbene (4′-MeO-4-HS), 4-hydroxy-4′-methyl-trans-stilbene (4′-Me-4-HS), 4-hydroxy-4′-nitro-trans-stilbene (4′-NO2-4-HS), and 4-hydroxy-4′-trifluoromethyl-trans-stilbene (4′-CF3-4-HS). The radical-scavenging activity and detailed mechanism of resveratrol and its analogs (ArOHs) were studied by the reaction kinetics with galvinoxyl (GO·) and 2,2-diphenyl-1-picrylhydrazyl (DPPH·) radicals in ethanol and Et acetate at 25 °C, using UV-visible spectroscopy. The reaction rates increase with increasing the electron-rich environment in the mols., and the compound bearing o-dihydroxyl groups (3,4-DHS) is the most reactive one among the examined resveratrol analogs. The effect of added acetic acid on the measured rate constant for GO·-scavenging reaction reveals that in ethanol that supports ionization solvent besides hydrogen atom transfer (HAT), the kinetics of the process is partially governed by sequential proton loss electron transfer (SPLET). In contrast to GO·, DPPH· has a relatively high reduction potential and therefore enhances the proportion of SPLET in ethanol. The relatively low rate constants for the reactions of ArOHs with GO· or DPPH· in Et acetate compared with the rate constants in ethanol prove that in Et acetate these reactions occur primarily by the HAT mechanism. The contribution of SPLET and HAT mechanism depends on the ability of the solvent to ionize ArOH and the reduction potential of the free radical involved. Also, the fate of the ArOH-derived radicals, i.e., the phenoxyl radicals, was studied by the oxidative product anal. of ArOHs and GO· in ethanol. The major products were dihydrofuran dimers in the case of resveratrol, 4,4′-DHS, and 4-HS and a dioxane-like dimer in the case of 3,4-DHS. It is suggested from the oxidative products of these ArOHs that the hydroxyl group at the 4-position is much easier to subject to oxidation than other hydroxyl groups, and the dioxane-like dimer is formed via an o-quinone intermediate.
Journal of Organic Chemistry published new progress about Antioxidants. 112-63-0 belongs to class esters-buliding-blocks, and the molecular formula is C19H34O2, Related Products of 112-63-0.
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