SET-12 is a highly active and selective antiparasitic agent against Leishmania amazonensis. It demonstrates outstanding activity against the promastigote form of the parasite, with an IC₅₀ of 10.89 μM and a selectivity index (SI) of up to 12.1. Additionally, SET-12 is effective against intracellular amastigotes, with an IC₅₀ of 3.81 μM and an SI that increases to 34.5. SET-12 also induces signs of apoptosis in the parasites, such as mitochondrial damage and the accumulation of reactive oxygen species (ROS).