[en] glutathione peroxidase ; diselenide and selenide derivatives ; Ebselen ; electron paramagnetic resonance ; lipid peroxidation
[en] Four analogues of Ebselen were synthesized and their glutathione peroxidase activity and antioxidant property evaluated and compared to Ebselen. Among the studied compounds, only diselenide  exhibited both glutathione peroxidase activity and radical-scavenging capability. Compounds  and  showed a strong inhibitory effect (53% and 43%, respectively) on the lipid peroxidation of linoleic acid compared to Ebselen and selenide derivatives ( and ) which were less active (28%, 26% and 18% inhibition, respectively). A concentration-dependent inhibitory effect was also found in the model of the formation of ABTS*+ radical cation: 65% and 89% inhibition for compound  at 10(-4) M and 5 x 10(-5) M, respectively, and 68% and 90% for compound , compared to 14% and 52% inhibition for Ebselen and the diselenides  and  (29%, 46% and 45%, 68%, respectively). By EPR spin trapping technique, the following inhibitory profile of the Ebselen analogues was observed towards the formation of thiyl radicals: Ebselen = >>>. Studies with compound  are in progress on oxidative stress cell models.