Loss of artemisinin produced by Artemisia annua L. to the soil environment

Artemisia annua L synthesizes and accumulates the secondary metabolite artemisinin, a compound with antimalarial properties. As cultivation of the plant is still the only cost effective source of artemisinin, the production takes place in monocultures of A. annua. Artemisinin is known to have insecticidal and herbicidal effects, and also of being toxic to A. annua. Knowing the magnitude of the different routes of loss of artemisinin from A. annua to the soil environment makes it possible to reduce the risk of decrease in yield as well as reducing the impact on soil organisms including plants, and reducing the risk of leaching. The largest contributor (86-108%) of artemisinin loss to the soil environment was found to be from dead leaves. In the case with A. annua production, the risks can hence be limited by paying attention to the harvest and drying process, where risk of loss of plant material to the surrounding environment is the largest. Artemisinin is also lost from A. annua by rain runoff (<0.5%) and root excretion, but to a minor degree. The in situ silicone tube microextraction method was here successfully applied for the first time to monitor artemisinin from roots in an A. annua soil-plant system. (C) 2012 Elsevier B.V. All rights reserved.