title: Relative reactivity of dihydropyridine derivatives to electrogenerated superoxide ion in DMSO solutions: a voltammetric approach.
abstract: 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.
authors.affiliation: Bioelectrochemistry Laboratory, Chemical, and Pharmaceutical Sciences Faculty, University of Chile, PO Box 233, Santiago 1, Chile.
authors.forename: María Eugenia
authors.initials: ME
authors.lastname: Oriz
authors.forename: Luis Joaquin
authors.initials: LJ
authors.lastname: Núñez-Vergara
authors.forename: Juan Arturo
authors.initials: JA
authors.lastname: Squella
mesh_terms: D004095:Dihydropyridines / Q000737:chemistry* / Q000378:metabolism; D004121:Dimethyl Sulfoxide / Q000737:chemistry* / Q000378:metabolism; D004572:Electrolysis / Q000379:methods*; D013481:Superoxides / Q000737:chemistry* / Q000378:metabolism
chemical_list: D004095:Dihydropyridines; D013481:Superoxides; D004121:Dimethyl Sulfoxide