Sesquiterpenes from the aerial parts of Artemisia vachanica krasch. ex poljakov and their anti-inflammatory and anti-diabetic activities

Eleven undescribed sesquiterpenes, vachanins A−K covering types of germacrane, eudesmane, guaiacane, and cadinane, along with fifteen known analogs were isolated from the aerial parts of Artemisia vachanica Krasch. ex Poljakov. Their structures were established on the basis of HRMS and NMR data, and their absolute configurations were successfully determined by single-crystal X-ray diffraction analysis, ¹³C-NMR calculations and DP4+ probability analysis, and ECD data in corporation with quantum chemical calculations. Vachanin A is the first example of germacrane bearing an uncommon C₅, C₁₀-oxygen bridge. All isolated compounds were assayed for anti-inflammatory and anti-diabetic activities. Compounds 15 and 22 presented weak anti-inflammatory activity by inhibiting the release of NO in RAW 264.7 cells induced by LPS with IC₅₀ values of 42.82 ± 1.43, and 63.37 ± 3.28 μM.