Chemical Constituents from Termite‐associated Xylaria acuminatilongissima YMJ623

Abstract Three previously unreported benzofurans, namely acumifurans A–C (1–3), along with five known compounds, 2‐(isopropyl‐1′‐ol)‐2,3‐dihydrobenzofuran‐5‐carbinol (4), fomannoxin alcohol (5), fomannoxin (6), acremine S (7) and cyclo(L‐Pro‐L‐Leu) (8), were isolated from the ethyl acetate extracts of the fermented broths of termite n est associated Xylaria acuminatilongissima YMJ623. Compound 4, a synthe tic benzofuran analogue of 1–3, was isolated for the first time from natural resources. The str uctures of 1–8 were determined through spectroscopic data analyses. The absolute configurations of 1–4 were established based mainly on ROESY experiment and Mosher’s reaction, and compared the optical rotation data with the literatures. The effects of these compounds on the inhibition of NO production in lipopolysaccharide (LPS)‐activated murine macrophage RAW264.7 cells were also evaluated. Of the compounds tested, 6 showed a mild NO production inhibitory activity without any cytotoxicity, and its mean maximum inhibition (Emax) at 100 μM was 42.98±0.87 %.