Extraction and Quantification of Artemisinin Compounds

To prepare an extract of A. annua, 35 g of dried plant leaves (combined harvested lots 2012–2015 for DLAeS and 2013–2014 for DLAeG) were aliquoted into 1 g samples in separate 50 mL test tubes to which 20 mL of methylene chloride were added prior to water bath sonication for 30 min at room temperature. Extract was separated from residual plant solids, pooled and evaporated under N₂ at 30 ℃. Extraction was repeated twice, pooled, filtered through glass wool in a Pasteur pipette, evaporated under N₂ and stored at −4 ℃ until use. AN was analyzed using GC-MS and quantified using authentic AN according to the method detailed in Martini et al. (16 (link)). Artemisinin (AN), artemether (AM), artesunate (AS), and dihydroartemisinin (DHA) were ordered from Cayman Chemical and solubilized in 100% filter sterilized DMSO to produce master stock solutions of 70 mM for Candida experiments.