New sesquiterpene and thiophene derivatives from Artemisia rupestris

A new sesquiterpene, rupestrisin A (1), and three new thiophene derivatives, rupestrienes A–C (2–4), were isolated from Artemisia rupestris. Their structures were determined by analyses of MS and NMR spectroscopic data, and the absolute configuration of 1 was established by calculated ECD spectra using time-dependent density functional theory. In in vitro bioassays, compounds 1–4 showed inhibitory effects on LPS-stimulated NO production in BV-2 microglial cells with IC₅₀ values of 24.3, 20.3, 8.5, and 5.3 μM, respectively.