Artemisia annua L.: a source of novel antimalarial drugs.

Artemisia annua L. contains artemisinin, an endoperoxide sesquiterpene lactone, mainly in its leaves and inflorescences. This compound and a series of derivatives have attracted attention because of their potential value as antimalarial drugs. In this review a survey of the currently available literature data is given. It includes phytochemical aspects, such as constituents of A. annua, the artemisinin content during the development of the plant and its biosynthesis, isolation, analysis and stability. Total chemical synthesis of artemisinin is referred to, as well as structure-activity relationships of derivatives and simplified analogues. Pharmacological studies are summarized, including the mechanism of action, interaction of the antimalarial activity with other drugs, possible occurrence of resistance to artemisinin, clinical results, toxicological aspects, metabolism and pharmacokinetics. Finally, plant cell biotechnology is mentioned as a possible means to obtain plants and cell cultures with higher artemisinin contents, allowing an industrial production of pharmaceuticals containing this novel drug.