Chemical constituents from Artemisia rupestris and their neuraminidase inhibitory activity.

Two new thiophene derivatives (1 and 2), a new sesquiterpene (3), and 15 known compounds (4-18) were isolated from the whole plants of Artemisia rupestris. The new compounds (1-3) were elucidated by extensive spectroscopic techniques including 1 D (1H and 13C) and 2 D NMR experiments (COSY, HSQC, HMBC and NOESY), and HR-ESI-MS. Most of the isolates (1-6, 8, 10-18) exhibited the neuraminidase inhibitory activity with IC50 values ranging from 74.07-986.54 µM by a fluorescence-based assay. Two known flavonoids (chrysosplenetin B and luteolin) showed a comparable activity to oseltamivir acid on neuraminidase inhibition.