Relative reactivity of dihydropyridine derivatives to electrogenerated superoxide ion in DMSO solutions: a voltammetric approach.
OBJECTIVE
To evaluate the reaction of a large series of pharmacologically significant 1,4-dihydropyridine (1,4-DHP) compounds with superoxide (O2.-) in dimethylsulfoxide using differential pulse voltammetry and controlled potential electrolysis.


METHODS
Differential pulse voltammetry was used to track the consumption of O2.-, and controlled potential electrolysis was used to electrogenerate O2.-.


RESULTS
With the addition of 1,4-DHP, the oxidation peak current of O2.- decreased concentration dependently, suggesting that 1,4-DHP reacts with O2.-, that is, 1,4-DHP scavenges O2.- in dimethylsulfoxide.


CONCLUSIONS
very easy and direct voltammetric procedure to study the relative reactivity of different 1,4-DHP with O2.- is proposed. Using the proposed method we have found that all commercial 1,4-DHP reacts with O2.-. The following order of rates was obtained: felodipine > or = vitamin E > isradipine > nimodipine > furnidipine > nitrendipine > nisoldipine > nifedipine. Furthermore, it was demonstrated that the hydrogen at the N-position of 1,4-DHP compounds could be released as a proton in the presence of O2.-, thus the electrogenerated O2.- worked as a proton acceptor to 1,4-DHP.
Oriz
María Eugenia
ME
Bioelectrochemistry Laboratory, Chemical, and Pharmaceutical Sciences Faculty, University of Chile, PO Box 233, Santiago 1, Chile.
Núñez-Vergara
Luis Joaquin
LJ
Squella
Juan Arturo
JA
D004095:Dihydropyridines / Q000737:chemistry* / Q000378:metabolism; D004121:Dimethyl Sulfoxide / Q000737:chemistry* / Q000378:metabolism; D004572:Electrolysis / Q000379:methods*; D013481:Superoxides / Q000737:chemistry* / Q000378:metabolism
D004095:Dihydropyridines; D013481:Superoxides; D004121:Dimethyl Sulfoxide