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Kinetic Reaction Mechanism of Sinapic Acid Scavenging NO2 and OH Radicals: A Theoretical Study.

ABSTRACT: The mechanism and kinetics underlying reactions between the naturally-occurring antioxidant sinapic acid (SA) and the very damaging ·NO2 and ·OH were investigated through the density functional theory (DFT). Two most possible reaction mechanisms were studied: hydrogen atom transfer (HAT) and radical adduct formation (RAF). Different reaction channels of neutral and anionic sinapic acid (SA-) scavenging radicals in both atmosphere and water medium were traced independently, and the thermodynamic and kinetic parameters were calculated. We find the most active site of SA/SA- scavenging ·NO2 and ·OH is the -OH group in benzene ring by HAT mechanism, while the RAF mechanism for SA/SA- scavenging ·NO2 seems thermodynamically unfavorable. In water phase, at 298 K, the total rate constants of SA eliminating ·NO2 and ·OH are 1.30×108 and 9.20×109 M-1 S-1 respectively, indicating that sinapic acid is an efficient scavenger for both ·NO2 and ·OH.

SUBMITTER: Lu Y

PROVIDER: S-EPMC5021273 | biostudies-literature | 2016

REPOSITORIES: biostudies-literature

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Kinetic Reaction Mechanism of Sinapic Acid Scavenging NO2 and OH Radicals: A Theoretical Study.

Lu Yang Y Wang AiHua A Shi Peng P Zhang Hui H Li ZeSheng Z

PloS one 20160913 9

The mechanism and kinetics underlying reactions between the naturally-occurring antioxidant sinapic acid (SA) and the very damaging ·NO2 and ·OH were investigated through the density functional theory (DFT). Two most possible reaction mechanisms were studied: hydrogen atom transfer (HAT) and radical adduct formation (RAF). Different reaction channels of neutral and anionic sinapic acid (SA-) scavenging radicals in both atmosphere and water medium were traced independently, and the thermodynamic ...[more]

PMID: 27622460

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