Artemilavanolides A and B, two sesquiterpenoids with a 6-oxabicyclo[3.2.1]octane scaffold from Artemisia lavandulaefolia

Artemilavanolides A (1) and B (2), two unprecedented sesquiterpenoids with 6-oxabicyclo[3.2.1]octane scaffold, as well as one known biogenetically related sesquiterpenoid, 11β,13-dihydrosantamarin (3), were isolated from the aerial parts of Artemisia lavandulaefolia. The structures and absolute configurations of 1 and 2 were characterized by analysis of HRESIMS, NMR spectroscopic, single crystal X-ray diffraction, and electronic circular dichroism (ECD) data. The plausible biogenetic pathway for 1 and 2 was also proposed. Compound 1 was found to enhance the neurite outgrowth of NGF-mediated PC12 cells at a concentration of 10 μM.