Five Sesquiterpenes from Paraconiothyrium sp. and Their Anti-inflammatory Activity

Five eremophilane sesquiterpenes including three new ones, named paraconions A-C (1-3), were isolated from an endophytic fungus, Paraconiothyrium sp. from Artemisia selengensis. The structures of these new compounds were established based on spectroscopic methods, including nuclear magnetic resonance (NMR), ultraviolet (UV), and infrared (IR) spectroscopy, as well as high resolution electrospray ionization mass spectrometry (HR-ESI-MS). An anti-inflammatory assay indicated that paraconion B (2) inhibited lipopolysaccharide-induced nitric oxide (NO) production in RAW 264.7 cells, with an IC₅₀ value of 51.7 μM. The compounds discovered in this study will enrich the structural types of secondary metabolites of the endophytic fungus Paraconiothyrium sp.