Determination of superoxide dismutase-like activity of copper(II) complexes. Relevance of the speciation for the correct interpretation of in vitro O2- scavenger activity.
The superoxide dismutase activity of several copper(II) complexes of linear and cyclic dipeptides has been measured. The results of a classic indirect method (xanthine-xanthine oxidase) have been compared with those obtained by generation of the superoxide radical through 2-(3-benzoylphenyl)propionic acid (ketoprofen) photolysis. A simulation approach, based on the knowledge of the stability constants of the different complex species existing in experimental conditions, has allowed us to obtain the correct speciation and to use these data to calculate the pertinent catalytic constants.
Costanzo
L L
LL
Dipartimento di Scienze Chimiche, Università di Catania, Italy.
De Guidi
G
G
Giuffrida
S
S
Rizzarelli
E
E
Vecchio
G
G
D002384:Catalysis; D003300:Copper; D004151:Dipeptides; D016166:Free Radical Scavengers; D007700:Kinetics; D013329:Structure-Activity Relationship; D013482:Superoxide Dismutase / Q000378:metabolism*
D004151:Dipeptides; D016166:Free Radical Scavengers; D003300:Copper; D013482:Superoxide Dismutase