Terpenoid and phenolic metabolites from the fungus xylaria sp. associated with termite nests

Abstract

Three new sesquiterpene acids, xylaric acids A-C (1-3, resp.), and a new tetralone (=3,4-dihydronaphthalen-1(2H)-one) derivative, 4, along with nine known compounds, xylaric acid D (5), hydroheptelidic acid (6), gliocladic acid (7), chlorine heptelidic acid (8), trichoderonic acid A (9), 16-(α-D-mannopyranosyloxy)isopimar-7-en-19-oic acid (10), 16-(α-D-glucopyranosyloxy)isopimar-7-en-19-oic acid (11), 5-carboxymellein (12), and naphthalen-1,8-diol 1-O-α-D-glucopyranoside (13) have been isolated from the solid culture of the ascomycete fungus Xylaria sp. associated with termite nest. The structures of these compounds were elucidated primarily by NMR experiments. The absolute configurations of compounds 1-3 and 5-9 were determined by combination of X-ray data and CD spectral analysis. The absolute configuration of 4 was assigned by Snatzke's method. Compounds 8 and 11 showed slight cytotoxicities against two cell lines A549 and SGC7901.