Alkaloids with anti-inflammatory activity from the endophytic fungus Penicillium sp. HZ-5

A chemical investigation of the ethyl acetate extract of the endophytic fungus Penicillium sp. HZ-5 derived from the leaf of Hypericum wilsonii N. Robson, led to the discovery of four alkaloids, including two undescribed compounds, penibutanoic A (1), a suspected extracting artefact, and penibutanoic B (2), along with two known compounds (3 and 4). Their structures were characterised by extensive spectroscopic and ECD calculations. Remarkably, the anti-inflammatory activities evaluation results revealed that compounds 1 and 2 possessed a moderate NO production inhibitory effects with the IC₅₀ values of 14.6 ± 0.2 and 13.9 ± 0.8 µM, respectively.