Industrial Crops and Products 43 (2013) 132–140 Contents lists available at SciVerse ScienceDirect Industrial Crops and Products journa l h o me pag e: www.elsevier.com/locate/indcrop Loss of artemisinin produced by Artemisia annua L. to the soil environment Karina K. Jessing a,∗ , Nina Cedergreen a , Philipp Mayer a,b , Lynn Libous-Bailey c , Bjarne W. Strobel a , Agnes Rimando d , Stephen O. Duke d a Department of Basic Science and Environment, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark b Department of Environmental Science, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark c United States Department of Agriculture, Crop Protection Systems Research Unit, 141 Experiment Station Rd. Stoneville, MS 38776-0350, USA d United States Department of Agriculture, Natural Product Utilization Research, University of Mississippi, University, MS, 38677-8048, USA a r t i c l e i n f o Article history: Received 7 March 2012 Received in revised form 19 June 2012 Accepted 22 June 2012 Keywords: Production Yield Environment In situ silicone microextraction a b s t r a c t 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. © 2012 Elsevier B.V. All rights reserved. 1. Introduction 1.1. Cultivation of Artemisia annua as a medicinal plant Artemisia annua L. (sweet wormwood, annual wormwood, sweet annie, sweet sagewort) synthesizes and accumulates the secondary metabolite artemisinin (Klayman, 1985), a sesquiterpene lactone with an endoperoxide bridge (Liu et al., 1979). A. annua and artemisinin have gained considerable attention during the last three decades due to the antimalarial properties of artemisinin against chloroquine-resistant strains of Plasmodium falciparum (Klayman, 1985). At present, total chemical synthesis (Abdin et al., 2003) or in vitro production of artemisinin (Arsenault et al., 2008) is not economically feasible, and cultivation of the plant is still the only cost effective source of artemisinin. Synthesis of artemisinin is now possible from artemisinic acid (Levesque and Seeberger, 2012), making artemisinin medication cheaper, but the only source of artemisinic acid is extraction from field grown A. annua. A. annua is cropped in large scale in China, Vietnam, Turkey, Iran, Afghanistan and Australia for medicinal purposes (Bhakuni et al., 2001), and the A. annua area in Africa covers at least 5000 ha, while ∗ Corresponding author. E-mail address: jessing@life.ku.dk (K.K. Jessing). the cropped area worldwide for medicinal purposes is estimated to be 12,000 ha. In Eastern Europe the plant is also cropped for extraction of essential oils (Heemskerk et al., 2006). In addition, A. annua is cultivated for experimental purposes in The Netherlands, Switzerland, Finland (Laughlin et al., 2002) and Denmark. Com- mercial A. annua is cultivated in monocultures to produce as much artemisinin as possible, and much effort is invested into enhancing the artemisinin yield (Abdin et al., 2003). The plants are harvested before flowering and left on the field to dry before the dry plant material is transported to extraction facilities. 1.2. Artemisinin distribution in A. annua Artemisinin is stored in glandular trichomes on the surface of the leaves and stem (Duke and Paul, 1993) and on the corolla and on receptacles of the florets. The majority of artemisinin is, however, located in trichomes on the leaves (Janick and Ferreira, 1996). The glandular trichomes consist of 10 cells where the two most apical cells form a bilobed sac by the filling and expansion of the space between the external cell walls and cuticle with secre- tory products. The subcuticular space in this sac stores secondary metabolites, including artemisinin. The trichomes burst as they mature and artemisinin is leaked to the leaf surface (Duke and Paul, 1993). Younger leaves have greater trichome density and produce more artemisinin per unit of fresh or dry weight than old leaves 0926-6690/$ – see front matter © 2012 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.indcrop.2012.06.033