Derived from sweet wormwood, artemisinin is a sesquiterpene lactone, a member of the terpenoids, a major class of highly variable organic chemicals found extensively in flowering plants and familiar to us for their aromatic qualities.
Along with related compounds, artemisinin is an effective drug against Malaria, a devatating disease caused by the mosquito-borne parasite, Plasmodium, widespread in areas with summer temperatures of at least 27-28°C.
Since the 1700s quinine, derived from the tropical tree Cinchona, has been used to provide some control of the disease but with prolonged use, Plasmodium has gradually developed resistance. Recently, new anti-malarial drugs have been developed from wormwood.
This annual plant grows rapidly to harvestable age, yielding much cheaper drugs. However, its exclusive use as a monotherapy is discouraged by the World Health Organisation as there is evidence that some malarial parasites are already developing resistance.
Artemisinin (or qinghaosu) has traditionally been used in Chinese medicine to treat many illnesses, including skin diseases and malaria, with the earliest references around 200 BC.