N- and O-Prenylated Quinolones: Syntheses and <i>In Vitro</i> and <i>In Vivo</i> Antischistosomal Evaluation

Schistosomiasis is a parasitic disease that affects millions of people but has only one treatment option (praziquantel) available. There is concern about the emergence of praziquantel-resistant schistosomes and the need for the development of new molecules to complement and/or act as an alternative to praziquantel. Prenylated quinolones are natural products generally produced by bacteria, wherein they are used as quorum-sensing molecules. Inspired by nature, we have synthesized 37 mimetics of these naturally produced molecules and established their in vitro antischistosomal activity against schistosomula and adult Schistosoma mansoni worms. Several hits with low micromolar (<3 μM) activity against both schistosomula and adult S. mansoni worms were identified. These hits are fast-acting, demonstrating greater than 50% inhibition of adult worms within 4 h at a concentration of 10 μM. Among them, KK37, a diprenylated quinolone, showed moderate in vivo activity, achieving 48% worm burden reduction at 200 mg/kg.