A structural analog of EUK 8 and EUK 134 with significantly reduced activity. Acts as a synthetic catalytic scavenger of reactive oxygen species with superoxide dismutase (SOD) and catalase mimetic activity. Superoxide-mediated reduction of an electron acceptor (i.e., SOD mimetic activity) was inhibited by EUK 118 with an IC₅₀ value of 2.0 µm.