Two undescribed bisabolane-type sesquiterpenoids from the endophytic fungus Penicillium herquei

Sixteen compounds, including two undescribed bisabolane-type sesquiterpenoids (1, 2), four aromatic derivatives (3–6), two cyclopeptides (7, 8), two acyclic sesquiterpenes (9–10), four fatty acid esters (11–14) and two fatty acids (15–16), were separated from the endophytic fungus Penicillium herquei. Their structures were established by analysis of spectroscopic data, HRESIMS spectra, NMR data and comparison with data in relevant literature. It is the first time that all of these compounds were isolated from P. herquei. The in vitro cytotoxicity of all isolated was evaluated against four tumor cell lines (HCT116, A549, HeLa, and Hepg2 cells) by the MTT assay, and compounds 1, 2, 4, 7 and 8 exhibited cytotoxicity with IC50 values ranging from 9.7 ± 0.8 to 37.4 ± 2.5 μM.