Euphraticanoids N–T: Aromadendrane-Type Diterpenes and Sesquiterpenes with Fungicidal Activities from Populus euphratica Resins

Seven previously undescribed terpenoids, including five prenylaromadendrane-type diterpenes euphraticanoids N–R (1–5) and two aromadendrane-type sesquiterpenes, euphraticanoids S and T (6 and 7), were isolated from Populus euphratica resins. Their structures, including their absolute configurations, were elucidated by HRESIMS and spectroscopic analysis, ECD calculations, and crystallographic methods. In addition, an evaluation of the fungicidal activities of compound 1 was carried out, resulting in the discovery of 1 as a fungicidal candidate lead compound with an EC50 of 15.7 and 68.6 mg/L against Curvularia mebaldsii and Fusarium graminearum, respectively.