New Iron Twist to Chloroquine─Upgrading Antimalarials with Immunomodulatory and Antimicrobial Features.

Herein, upgraded chloroquine (CQ) derivatives capable of overcoming resistance and, at the same time, suppressing excessive immune response and risk of concurrent bacteremia were developed. Twelve new ferrocene- hybrids tethered with a small azathia heterocycle (1,3-thiazolidin-4-one, 1,3-thiazinan-4-one, or 5-methyl-1,3-thiazolidin-4-one) were synthesized and fully characterized. All hybrids were evaluated for their in vitro antiplasmodial, antimicrobial, and immunomodulatory activities. Additional assays were performed on selected hybrids to gain insights into their mode of action. Although only hybrid was more potent than the parent drug toward -resistant Dd2 strain, several other hybrids (such as , , and ) manifested substantially improved antimicrobial and immunomodulatory properties. Interesting structure-activity relationship data were obtained, hinting at future research for the development of new multitarget chemotherapies for malaria and other infectious diseases complicated by drug resistance, bacterial co-infection, and immune-driven pathology issues.