Antiparasitic agent-28 is an orally active and selective inhibitor of Toxoplasma gondii phenylalanine tRNA synthetase (TgcPheRS), capable of crossing the blood-brain barrier. It effectively inhibits the growth of T. gondii tachyzoites (TgME49-Fluc strain) with an EC50 of 1 nM, as well as alkaline-induced T. gondii bradyzoites (Tg68nLuc strain) with an EC50 of 3 nM, and glutamine-rich medium-induced bradyzoites with an EC50 of 0.1 nM. Antiparasitic agent-28 demonstrates significant anti-toxoplasmosis efficacy in mice infected with TgME49-Fluc tachyzoites and is utilized in studies involving Toxoplasma gondii infections.