|Jessing, Karina -|
|Cedergreen, Nina -|
|Mayer, Philipp -|
|Strobel, Bjarne -|
Submitted to: Industrial Crops and Products
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 22, 2012
Publication Date: August 8, 2012
Citation: Jessing, K.K., Cedergreen, N., Mayer, P., Libous Bailey, L.M., Strobel, B.W., Rimando, A.M., Duke, S.O. 2012. Loss of artemisinin produced by Artemisia annua L. to the soil environment. Industrial Crops and Products. 43:132-140. Interpretive Summary: Artemisinin, an important drug, is produced by the plant Artemisia annua (annual wormwood). This plant is grown in monocultures to produce the drug. Artemisinin is known to be phytotoxic to both annual wormwood and other plants. This work was conducted to determine the route of artemisinin from the crop to the soil in order to design strategies for reducing loss of this valuable compound during production. The largest source of loss was found to be leaching from dead leaves. Thus, harvesting of plant material as soon as possible is recommended to maximize yield and to reduce incorporation of this phytotoxic material into the soil where it might cause autotoxicity.
Technical Abstract: 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 dead leave decay. 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 and root excretion but to a minor degree. The in situ silicone tube microextraction method was here successfully applied for the first time to artemisinin and to the A. annua soil-plant system.