The prediction of antioxidant properties is not straightforward due to the complexity of the in vivo systems. Here, we use theoretical descriptors, including the potential of ionization, the electrodonating power and the spin density distribution, to characterize the antioxidant capacity of edaravone (EDV) derivatives. Our computations reveal the relationship between these parameters and their potential bioactivity as free radical scavengers. We conclude that more efficient antioxidants could be synthesized by tuning the R-1 and R-2 positions of the EDV structure, rather than modifying the R-3 group. Such modifications might improve the antioxidant activity in neutral and deprotonated forms. (C) 2014 Elsevier B. V. All rights reserved.