Amidines: The Main Discoveries in the Synthesis and Anti-Leishmanial Effects of New Chemotherapeutic Agents

Leishmaniasis is an infectious disease caused by protozoan parasites of the Leishmania genus and affects more than 90 countries, especially in tropical and subtropical regions. The first treatment for these diseases involves pentavalent antimonial derivatives, which are very toxic and cause severe side effects. The other chemotherapeutic drugs used as second-line agents include different organic compound classes, such as pentamidine, which also cause severe side effects. Thus, new, safer, and efficient antileishmaniasis agents are urgently needed to control and treat these diseases. This mini review, which considered the last two decades of related research, highlighted the principal synthetic methodologies used to access amidine derivatives, focusing on more eco-friendly methods. Furthermore, the results obtained from evaluations of the anti-Leishmania activity and several molecular targets of the amidine derivatives are highlighted.