Neuraminidase Inhibitory Constituents From <i>Artemisia rupestris</i> L.

Artemisia rupestris L. has been utilized as a traditional Uygur herb for the treatment of colds and fevers. In this study, six novel compounds, including three sesquiterpenoids (1-3), a thiophene (4), an acetylenic spiroketal enol ether (5), and a chromone glycoside (6), along with 20 known compounds (7-26), were successfully isolated from the entire plant of the herb. The structural elucidation of these new compounds (1-6) was achieved through a comprehensive application of spectroscopic techniques, encompassing 1D and 2D NMR experiments, which included ¹H-¹H COSY, HSQC, HMBC, and NOESY, complemented by HRESIMS. All the isolates were assessed for their neuraminidase inhibitory activity using a fluorescence-based assay. Most of the isolated compounds demonstrated the potential activity, with IC₅₀ values ranging from 40.30 to 186.43 µM. Notably, a known flavonoid glycoside, tilianin, exhibited potent activity, with a IC₅₀ values of 40.30 µM.