Our
previous work identified a series of 12 xanthoquinodin analogues
and 2 emodin-dianthrones with broad-spectrum activities against Trichomonas vaginalis, Mycoplasma
genitalium, Cryptosporidium parvum, and Plasmodium falciparum. Analyses
conducted in this study revealed that the most active analogue, xanthoquinodin
A1, also inhibits Toxoplasma gondii tachyzoites and the liver stage of Plasmodium berghei, with no cross-resistance to the known antimalarial targets PfACS,
PfCARL, PfPI4K, or DHODH. In Plasmodium, inhibition
occurs prior to multinucleation and induces parasite death following
12 h of compound exposure. This moderately fast activity has impeded
resistance line generation, with xanthoquinodin A1 demonstrating an
irresistible phenotype in both T. gondii and P. falciparum.