Terpenoids from the endophytic fungus Microdiplodia sp. and their anti-inflammatory activities

Motivated by the potential anti-inflammatory effect of the crude extract of endophytic fungus Microdiplodia sp. CJ01 derived from Camellia sinensis, chemical investigation of the extract of Microdiplodia sp. CJ01 led to the isolation and identification of sixteen terpenoids, including five undescribed eremophilane sesquiterpenoids named microdiplodins A-E (1–5), one undescribed meroterpenoid 13-carboxymacrophorin A (13), seven known eremophilane sesquiterpenoids (6–12), and three known meroterpenoids (14–16). The structures of these compounds were elucidated based on extensive spectroscopic analysis, including nuclear magnetic resonance (NMR) and high-resolution mass spectrometry (HRMS) data. Their absolute configurations were determined by calculational and experimental electronic circular dichroism (ECD) data. Anti-inflammatory activity assays revealed that compounds 3, 4, 14–16 exhibited moderate inhibitory effects on the production of nitric oxide (NO) in the lipopolysaccharide (LPS)-induced RAW 264.7 macrophage cells.