Hydrogen abstraction ability of different aromatic nitroxides.
Indolinonic aromatic nitroxides have been shown to efficiently inhibit free radical mediated oxidation reactions in biological systems. Since all antioxidants also possess pro-oxidant activity, possibly through a hydrogen abstraction process from suitable substrates, the relative hydrogen abstraction abilities of these compounds were evaluated. Different hydrogen donors were reacted with an indolinic and two indolinonic nitroxides and the rates of hydrogen abstraction were determined using UV-Vis spectroscopy. From the data obtained, a structure-activity relationship was found. In addition, the hydrogen abstraction ability of these compounds was found to be much greater than that of the aliphatic nitroxide TEMPO, despite existing reports indicating that these two classes of compounds show similar antioxidant activities in biological systems.
Damiani
Elisabetta
E
Dipartimento di Scienze dei Materiali e della Terra, Università Politecnica delle Marche, Via Brecce Bianchi, I-60131 Ancona, Italy.
Astolfi
Paola
P
Benaglia
Massimo
M
Alberti
Angelo
A
Greci
Lucedio
L
D003497:Cyclic N-Oxides / Q000737:chemistry*; D005663:Furans / Q000737:chemistry; D006859:Hydrogen / Q000737:chemistry*; D019811:Hydroxylamine / Q000737:chemistry; D006898:Hydroxylamines / Q000737:chemistry; D007211:Indoles / Q000737:chemistry; D007700:Kinetics; D013056:Spectrophotometry, Ultraviolet; D013329:Structure-Activity Relationship
D003497:Cyclic N-Oxides; D005663:Furans; D006898:Hydroxylamines; D007211:Indoles; D019811:Hydroxylamine; C033314:N,N-diethylhydroxylamine; C018674:tetrahydrofuran; D006859:Hydrogen; C003959:TEMPO