Isolation of Sesquiterpenoids and Trypanocidal Constituents from Artemisia adamsii

Abstract The Mongolian Artemisia adamsii (A. adamsii) plant is of particular interest from both medicinal and ecological perspectives. In this study, three previously undescribed sesquiterpenoids (1–3) were isolated, along with 25 known compounds, from naturally dried and browned aerial parts of A. adamsii, which were collected in the autumn from the pasturelands of Bayan Soum, Tuv Province, Mongolia. The chemical structures of the isolated undescribed compounds, including their relative and absolute configurations, were elucidated by high-resolution mass spectrometry, nuclear magnetic resonance spectroscopy, and single crystal X-ray crystallography. The trypanocidal activities of the isolated compounds against six species, namely Trypanosoma brucei brucei, T. b. gambiense, T. b. rhodesiense, T. equiperdum, Trypanosoma congolense, and Trypanosoma evansi were evaluated. Consequently, a coumarin (fraxetin) and a flavonoid (jaceosidin) were identified as exhibiting relatively potent activities. Quantitative analysis by high-performance liquid chromatography confirmed relatively high contents of these compounds in A. adamsii, indicating that they represent the main functional components of this plant. These results further demonstrate the potential medicinal and ecological significance of A. adamsii.