Three previously unreported benzofurans, namely acumifurans A-C (1–3), along with five known compounds, 2-(isopropyl-I'-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 associated Xylaria acuminatilongissima YMJ623. Compound 4, a synthetic benzofuran analogue, was isolated for the first time from natural resources. The structures of 1-8 were determined through spectroscopic data analysis. The absolute configurations of 1-4 were established based mainly on ROESY experiment and Mosher's reaction, and compared with the optical rotation data of 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 average maximum inhibition (Emax) at 100 µM was 42.98±0.87%.
