Anisotanols A—D, Four Norsesquiterpenoids with an Unprecedented Sesquiterpenoid Skeleton from Anisodus tanguticus‡

Main observation and conclusion Anisotanols A—D (1—4), four new compounds possessing an unprecedented sesquiterpenoid skeleton with a congested tricyclic 6/3/5 ring system, were obtained from Anisodus tanguticus . Their structures were elucidated by comprehensive spectroscopic techniques, and the absolute configurations were confirmed via ECD calculations and single‐crystal X‐ray diffractions. A putative biosynthetic pathway for these compounds was proposed. Biological evaluation disclosed that compound 3 showed anti‐angiogenic activity by inhibiting the viability, migration, and tube formation in HUVECs.