Volvalerenone A, a new type of mononorsesquiterpenoid with an unprecedented 3,12-oxo bridge from Valeriana officinalis

Volvalerenone A (1), a new type of mononorsesquiterpenoid with an unprecedented 5/6/6 tricyclic ring system, was isolated from the roots of Valeriana officinalis, the official species of valerian used in Europe. The structure of volvalerenone A was elucidated based on its spectroscopic and single-crystal X-ray crystallography data. The absolute configuration was assigned by the computational method. A possible biosynthetic pathway of volvalerenone A was also proposed. Preliminary biological studies showed that volvalerenone A had weak inhibitory activity on acetylcholine esterase (AChE), and no enhancing activity on nerve growth factor (NGF)-mediated neurite outgrowth in PC12 cells was observed at 50 μM.