A new terpestacin-type sesterterpenoid with tricyclic 3/15/5 scaffold from an endophytic fungus <i>Neofusicoccum</i> sp. J019

Chemical investigation of an endophytic fungus, <i>Neofusicoccum</i> sp. J019, isolated from the plant species <i>Cynanchum chinense</i> R. Br., has led to the identification of an undescribed terpestacin-type sesterterpenoid, neofusistacin (<b>1</b>), together with two analogues (<b>2</b> and <b>3</b>). The structure of <b>1</b> was elucidated by extensive spectroscopic analyses including UV, IR, 1D, and 2D NMR, HRESIMS, and its absolute configuration was unambiguously confirmed by a single crystal X-ray diffraction analysis. Compound <b>1</b> is featured by a rare 3/15/5-fused tricyclic scaffold in terpestacin-type sesterterpenoid. The anti-inflammatory activities of compounds <b>1–3</b> were evaluated <i>in vitro</i>, but none of them showed obvious anti-inflammatory activities at the concentration of 100 μM. No antibacterial activity against <i>Escherichia coli</i> ATCC 25922, <i>Salmonella enterica</i> subsp. <i>enterica</i> ATCC 14028, and <i>Staphylococcus aureus</i> subsp. <i>aureus</i> ATCC 29213 was found for compounds <b>1–3</b> at the concentration of 100 μM.