摘要Teucrifarides A-D(1-4),four previously unreported neo-clerodane-type diterpenoids,combined with sixteen known analogs(5-20),were purified from Teucrium quadrifarium.The absolute forma of compounds 1-4 were determined via spectroscopic and ECD calculation methods,together with X-ray crystallography experiments.Among them,compound 1 possessed a 5,20-epoxy ring featuring a unique cage-like 12-oxatricyclo[5.3.2.01,6]undecane skeleton.Meanwhile,2 incorporated a 6,20-epoxy ring with a novel 12-oxatricyclo[6.2.2.02,7]undecane skeleton.Compounds 1 and 12 exhibited significant inhibitory effects against HT-22 cells ferroptosis induced by RSL3,with EC50 values of 11.8±1.0 μM,and 4.52±1.24 μM,respectively.Moreover,ROS accumulation in HT22 cells treated with compound 1 was also observed.