Ferriprotoporphyrin IX (FPIX) (FPIX)

Ferriprotoporphyrin IX (FPIX), also known as heme, is a toxic byproduct generated during the digestion of host hemoglobin by Plasmodium falciparum within its acidic food vacuole. To survive, the parasite detoxifies FPIX by sequestering it into an insoluble crystalline form called hemozoin (synthetic equivalent: beta-hematin). This biocrystallization process is a critical survival mechanism for the malaria parasite and serves as a primary target for several classes of antimalarial drugs. Quinolines, such as chloroquine, work by binding to FPIX or the growing crystal surface of hemozoin, thereby preventing further crystallization. The resulting accumulation of free, toxic FPIX leads to oxidative stress, membrane damage, and ultimately the death of the parasite.

Other names

HemeHematinHemozoinMalaria pigmentbeta-hematinFerrihemeFe(III)PPIX

Inhibition of hemozoin (beta-hematin) formation/crystallization, leading to the accumulation of toxic free ferriprotoporphyrin IX (FPIX) which causes oxidative stress and membrane damage.