首页|On the free radical scavenging and metallic ion chelating activities of pyridoxal - Could the pro-oxidant risk be competitive?

On the free radical scavenging and metallic ion chelating activities of pyridoxal - Could the pro-oxidant risk be competitive?

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? 2022 Elsevier LtdPrimary and secondary antioxidant activities of pyridoxal have been investigated by using density functional theory (DFT) at the M05–2X level combined with 6–311++G(d,p) basis set for non-metallic atoms and LanL2DZ for metallic ions. The former has been examined by its free radical scavenging activity towards HOO●, HO●, and NO2● via different mechanisms including formal hydrogen transfer (FHT), proton transfer (PT), single electron transfer (SET), and radical adduct formation (RAF). The latter has been accomplished through its transition metal-chelating ability with Fe(III)/Fe(II) and Cu(II)/Cu(I) ions. The results show that pyridoxal illustrates as an efficient radical scavenger, especially, for HO● and NO2● in water. The overall rate constants (koverall) for the reactions with HOO●, HO●, and NO2● radicals are 1.30 × 104, 5.76 × 109, and 1.43 × 109 M?1s?1, respectively. The SET from the anionic state is the most dominant for the HOO● and NO2● scavenging reactions, while both RAF and SET contribute largely to the reaction with highly reactive HO● radicals. Moreover, the anionic form of pyridoxal demonstrates a better role as a metal chelator than the neutral. However, the pro-oxidant risks of the formed complexes could be observed if there are superoxide radical anion (O2●–) and ascorbate (Asc–) in aqueous media.

AntioxidantDFT calculationsFree radicalsMetal chelatingPro-oxidantPyridoxalVitamin B6

Ngo T.C.、Truong D.H.、Dao D.Q.、Nguyen T.T.N.、Quang D.T.

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Institute of Research and Development Duy Tan University

Faculty of Pharmacy Duy Tan University

Department of Chemistry University of Education Hue University

2022

Phytochemistry

Phytochemistry

CCR
ISSN:0031-9422
年,卷(期):2022.199
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