Study on the specialized metabolites from the endophytic fungus Cercophora sp. UJN-EF001 in Vaccinium bracteatum

Thirteen compounds (1-13) were isolated from the ethanol extract of an endophytic fungus Cercophora sp. UJN-EF001 derived from Vaccinium bracteatum, using normal-phase silica gel column chromatography (CC), reversed-phase C₁₈ CC and high-performance liquid chromatography. The structures of these isolates were elucidated through spectroscopic methods including high-resolution mass spectrometry, nuclear magnetic resonance and electronic circular dichroism. Among them, two (1 and 2) were previously unreported molecules, two (3 and 4) were obtained for the first time as natural products, and nine (5-13) were isolated for the first time from the genus Cercophora. All 13 compounds were evaluated for their inhibitory activities against α-glucosidase and nitric oxide (NO) production. As a result, none of them exhibited significant inhibition toward α-glucosidase, while compound 13 displayed moderate inhibition against lipopolysaccharide-induced release of NO in RAW264.7 macrophages with an IC₅₀ value of 34.3 ± 3.8 μmol·L^-1.