Structural effects on the reactivity 1,4-dihydropyridines with alkylperoxyl radicals and ABTS radical cation.
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.
Yáñez
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Laboratory of Bioelectrochemistry, Faculty of Chemical and Pharmaceutical Sciences, University of Chile, PO Box 233, 8380492 Santiago, Chile.
López-Alarcón
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Camargo
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Valenzuela
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Squella
J A
JA
Núñez-Vergara
L J
LJ
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*
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