Artemisinin and a new generation of antimalarial drugs

Malaria is caused by the bite of a female mosquito (Anopheles), resulting in the malaria parasite, Plasmodium,  entering the human blood stream. Once a red blood cell has become invaded with the parasite, several rounds of asexual reproduction ensue, leading to its eventual rupture. It is the cyclic release of parasites from the red blood cells which causes the intermittent symptoms of fever, shivering and anaemia that are characteristic of malaria.

Of the four species of Plasmodium  that infect humans, the most dangerous is P. falciparum. This parasite accumulates in the capillaries of vital organs such as the brain, kidney, intestine and lungs. Cerebral malaria, the accumulation of P. falciparum  in the brain, is responsible for most of the deaths associated with malaria. 

During the red-cell cycle, the parasite uses the host's haemoglobin as food. The haemoglobin protein is broken down by enzymes and the parasite assimilates the amino acids which are released. The digestive process also liberates haem, the iron-containing porphyrin which is normally buried within the haemoglobin molecule. It is this free haem molecule, bearing an exposed Fe(II) atom at its centre, which provides the unique line of attack for the drug artemisinin (1).