Fifteen new cadinane sesquiterpenoids, amorphaenes A-O (1-15), along with one known compound, were isolated from an endophytic fungus Penicillium sp. HZ-5 collected from Hypericum wilsonii N. Robson. Notably, compound 7 was the first example of 11-nor cadinane sesquiterpenoid via the oxidative cleavage between C-11 and C-13. Their structures were elucidated by extensive spectroscopic analysis, singlecrystal X-ray diffraction and ECD calculation and comparison. Significantly, compounds 1, 5, 8, 13 and 16 exhibited glutamic oxaloacetate transaminase 1 (GOT1) inhibitory effects, with IC