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 tech-niques,and the absolute configurations were confirmed via ECD calculations and single-crystal X-ray diffractions.A putative biosyn-thetic 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.