Artemisinin is a drug used to treat multi-drug resistant strains of falciparum malaria. The compound (a sesquiterpene lactone) is isolated from the shrub Artemisia annua long used in traditional Chinese medicine. Not all shrubs of this species contain artemisinin. Apparently it's only produced when the plant is subjected to certain conditions, most likely biotic or abiotic stress. It can be synthesized from artemisinic acid. History Artemisia has been used by Chinese herbalists for more than… (More on Artemisinin)