Penicinoid A, an undescribed sesterterpenoid with cytotoxic activity from <i>Penicillium herquei</i>

Penicinoid A (<b>1</b>), a previously undescribed sesterterpenoid, and ten known compounds, variculanol (<b>2</b>), citreoanthrasteroid A (<b>3</b>), ergosta-7,22<i>E</i>-diene-2<i>β</i>,3<i>α</i>,9<i>α</i>-triol (<b>4</b>), (22<i>E</i>,24<i>R</i>)-23-methylergosta-7,22-diene-3<i>β</i>,5<i>α</i>,6<i>β</i>,9<i>α</i>-tetrol (<b>5</b>), 9,11-dehydroergosterol peroxide (<b>6</b>), (22<i>E</i>,24<i>R</i>)-3<i>β</i>,5<i>α</i>,9<i>α</i>-trihydroxy-ergosta-7,22-dien-6-one (<b>7</b>), gymnasterone C (<b>8</b>), cyathisterol (<b>9</b>), demethylincisterol A3 (<b>10</b>), volemolide (<b>11</b>), were obtained from <i>Aconitum carmichaelii</i> endophytic fungus <i>Penicillium herquei</i>. 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 <b>1</b>-<b>11</b> exhibited significant to weak cytotoxic effects (IC₅₀ values: 1.5 ± 0.1-37.3 ± 3.0 <i>μ</i>M). Additionally, their inhibitory activity on NO production in LPS stimulated RAW 264.7 macrophages were evaluated. Compounds <b>1</b>-<b>11</b> showed moderate to weak inhibitory activity (IC₅₀ values: 10.9 ± 1.0-35.1 ± 3.1 <i>μ</i>M). This is the first time that sesterterpenoids were found from the secondary metabolites of <i>P. herquei</i>.