One novel sesquiterpenoid from the fungus Pestalotiopsis clavata JSQ 12 isolated from the mushroom Lanmaoa asiatica

A novel sesquiterpenoid, designated as pestaloclactone (1), along with four previously reported compounds, namely pestaloporinate E (2), pestalotiopsin F (3), pestalotiopsin J (4), and pestaloporinate B (5), was isolated from the culture of the fungus Pestalotiopsis clavata JSQ 12. The structures of these compounds were elucidated primarily through a comprehensive analysis of MS, NMR, and specific rotation data. Furthermore, X-ray diffraction experiment was performed to confirm the absolute configuration of compound 1. Notably, the skeleton structure of pestaloclactone (1) is reported here for the first time. The isolated compounds were evaluated for their cytotoxic and antibacterial activities. Compound 1 demonstrated stronger inhibitory effects on BV2 and SH-SY5Y cells at a concentration of 40 µM, with IC50 values of 28.59 and 37.97 µM, respectively.