The mode of action of the antimalarial artemisinin and its derivatives.

1. Atremisinin (qinghaosu) is a sesquiterpene endoperoxide derived from a plant which was used in Chinese herbal medicine for thousands of years. 2. Artemisinin and its derivatives have potent antimalarial activity, and are now being used clinically in much of the world. 3. The artemisinin derivatives have an unusual mode of action involving the iron-catalyzed generation of a carbon-centered free radical followed by the alkylation of malaria-specific proteins.