title: Structural effects on the reactivity 1,4-dihydropyridines with alkylperoxyl radicals and ABTS radical cation.
abstract: A series of eight commercial C-4 substituted 1,4-dihydropyridines and other synthesized related compounds were tested for direct potential scavenger effect towards alkylperoxyl radicals and ABTS radical cation in aqueous Britton-Robinson buffer pH7.4. A direct quenching radical species was established. The tested 1,4-dihydropyridines were 8.3-fold more reactive towards alkylperoxyl radicals than ABTS cation radical, expressed by their corresponding kinetic rate constants. Furthermore, NPD a photolyte of nifedipine and the C-4 unsubstituted 1,4-DHP were the most reactive derivatives towards alkylperoxyl radicals. The pyridine derivative was confirmed by GC/MS technique as the final product of reaction. In consequence, the reduction of alkylperoxyl and ABTS radicals by 1,4-dihydropyridines involved an electron transfer process. Also, the participation of the hydrogen of the 1-position appears as relevant on the reactivity. Results of reactivity were compared with Trolox.
authors.affiliation: Laboratory of Bioelectrochemistry, Faculty of Chemical and Pharmaceutical Sciences, University of Chile, PO Box 233, 8380492 Santiago, Chile.
authors.forename: C
authors.initials: C
authors.lastname: Yáñez
authors.forename: C
authors.initials: C
authors.lastname: López-Alarcón
authors.forename: C
authors.initials: C
authors.lastname: Camargo
authors.forename: V
authors.initials: V
authors.lastname: Valenzuela
authors.forename: J A
authors.initials: JA
authors.lastname: Squella
authors.forename: L J
authors.initials: LJ
authors.lastname: Núñez-Vergara
mesh_terms: D052160:Benzothiazoles; D002412:Cations; D004095:Dihydropyridines / Q000737:chemistry*; D005609:Free Radicals; D013058:Mass Spectrometry; D010545:Peroxides / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D013451:Sulfonic Acids / Q000737:chemistry*
chemical_list: D052160:Benzothiazoles; D002412:Cations; D004095:Dihydropyridines; D005609:Free Radicals; D010545:Peroxides; D013451:Sulfonic Acids; C002502:2,2'-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid; C038806:1,4-dihydropyridine