A new cytotoxic phenalenone derivative from Penicillium oxalicum

From the supernatant of the fermentation broth of Penicillium oxalicum, we isolated a previously undescribed peniciphenalenin G (1) and three known compounds 2-4. Their chemical structures were established through spectroscopic analysis as well as comparing with data in the literature. Compound 1 displayed a moderate cytotoxicity with IC50 value 21.4 μM (positive drug regorafenib with IC50 value of 8.2 μM) against Caco2 cells while compounds 2 and 3 showed weak cytotoxicities with IC50 value of 52.1 and 39.2 μM, respectively.