Penicisepene, A New Sesquiterpenoid from the Fungus Penicillium sp. LPFH-Q3

The secondary metabolites of the strain Penicillium sp. LPFH-Q3 isolated from the sea sediment were investigated. A new eremophilane sesquiterpene, named penicisepene (1), along with seven known compounds (2-8) was obtained. The structures of the metabolites were elucidated based on spectroscopic analysis including 1H NMR, 13C NMR, 1H-1H COSY, HSQC, HMBC, NOESY, and the MS data. The absolute configuration of 1 was established via comparison of the experimental and density functional theory predicted ECD data. Compound 1, an eremophilane sesquiterpene containing a hexenic acid, was scarcely found in nature. Besides, the NMR data of 3 and 4 in methanol-d4 were reported for the first time. Biological evaluation showed that compounds 1, 3, and 4 showed inhibitory activity comparable to the positive control quercetin (16.7 uM) on NO production in LPS-activated RAW 264.7 macrophages with IC50 values of 13.2, 10.6, 17.9 uM, respectively.