Antimalarial Endoperoxides: from Natural Sesquiterpene Drugs to a Rising Generation of Synthetic Congeners

Malaria is a vector-borne tropical disease caused by protozoans belonging to the genus Plasmodium, which has been scourging mankind for hundreds of millions of years. Despite the masterful progress in preventing disease transmission and reducing morbidity and fatal outcomes, malaria is on the rise again. Global concerns are focused on the spread of resistance to current drugs in the management of severe or ultimately lethal P. falciparum infection. To fully exploit the potential of existing agents and overcome their critical drawbacks, novel synthetic and formulation approaches have been explored. In this field, the clinical value of the natural drug artemisinin (ART) and its derivatives have been firmly established, and ART combination therapies (ACTs) have been recommended as first-line treatment against infection caused by chloroquine-resistant (CQR) P. falciparum strains. Over time, however, ART treatment options have become inadequate, and strict demand for new and effective agents has emerged. In this chapter, the medicinal chemistry aspects of artemisinins will be discussed, covering their unique mode of action and their structural features in relation to stability, pharmacokinetic profile, and antiplasmodial activity. Beyond ACT strategies, significant classes of compounds obtained through both ART covalent bitherapy and dimerization approaches will be presented as well. Furthermore, a special section will focus on the most recent endoperoxide-based synthetic antimalarials as new powerful and cost-effective alternatives to the “golden drug”. It is expected that reported results will provide a strong incentive for further studies, and that unceasing research efforts will succeed in reaching the eventual eradication of this endemic plague.