Penicinoid A, an undescribed sesterterpenoid with cytotoxic activity from Penicillium herquei

Penicinoid A (1), a previously undescribed sesterterpenoid, and ten known compounds, variculanol (2), citreoanthrasteroid A (3), ergosta-7,22E-diene-2β,3α,9α-triol (4), (22E,24R)-23-methylergosta-7,22-diene-3β,5α,6β,9α-tetrol (5), 9,11-dehydroergosterol peroxide (6), (22E,24R)-3β,5α,9α-trihydroxy-ergosta-7,22-dien-6-one (7), gymnasterone C (8), cyathisterol (9), demethylincisterol A3 (10), volemolide (11), were obtained from Aconitum carmichaelii endophytic fungus Penicillium herquei. Their structures were characterised by NMR, HRESIMS, ECD calculations and comparison with the reported literatures. All isolates were screened on their cytotoxicity against A549, Hepg2, HeLa, and HCT116 cells. Compounds 1-11 exhibited significant to weak cytotoxic effects (IC₅₀ values: 1.5 ± 0.1-37.3 ± 3.0 μM). Additionally, their inhibitory activity on NO production in LPS stimulated RAW 264.7 macrophages were evaluated. Compounds 1-11 showed moderate to weak inhibitory activity (IC₅₀ values: 10.9 ± 1.0-35.1 ± 3.1 μM). This is the first time that sesterterpenoids were found from the secondary metabolites of P. herquei.