Malaria is a very serious infectious disease caused by protozoans of the genus Plasmodium and is
transmitted through the bite of infected female Anopheles mosquitoes. Every year, over one million
people die from malaria, especially in tropical and subtropical areas. Most of the deaths are attributed
to the parasite species Plasmodium falciparum. Many drugs have been investigated for their efficacy in
the treatment of the disease, but strains of P. falciparum resistant to some of these drugs have
appeared. Hence, the discovery of new classes of more potent compounds to treat the disease is
necessary [1–6]. Artemisinin (qinghaosu) has been used in traditional Chinese medicine to treat
disease for more than two million years. The medicine is extracted from the plant Artemisia annua L.
and is used to combat 52 species of diseases in the People’s Republic of China [7]. Artemisinin has a
unique structure with a stable endoperoxide lactone (1, 2, 13-trioxane) that is totally different from
previous antimalarials in its structure and mode of action. Artemisinin is remarkably effective against
Plasmodium falciparum and cerebral malaria [8]. Currently, semi-synthetic artemisinin derivatives play
an important role in the treatment of P. falciparum malaria [9–11]. Although the true mechanism of
their biological activity against malaria has not been completely elucidated, various studies suggest
that the trioxane ring is essential for antimalarial activity due to the properties displayed by the
endoperoxide linkage. The literature also suggests that free heme could be the target of artemisinin in
biological systems and that Fe2+ interacts with the peroxide when artemisinin reacts with heme [12–15].
Artemisinin and its derivatives induce a rapid reduction in the number of parasites when compared
with other known drugs. Consequently, they are of particular interest for severe cases of malaria. The
initial decline in the number of parasites is also beneficial for combination therapies. Therefore, there
is an enormous interest in the mechanism of action, chemistry and drug development of this new class
of antimalarials. The endoperoxide group is essential for the antimalarial activity and is mediated by
activated oxygen (superoxide, H2O2 and/or hydroxyl radicals) or carbon free radicals [16–19].