Secondary Metabolites from the Endophytic Fungus Xylaria cubensis

Seven new metabolites, including three sesquiterpenoids, 10-hydroxythujopsene (1), akotriol (2), and xylaritriol (3), one diterpenoid, cubentriol (4), one aliphatic derivative, akoenic acid (5), one alkaloid, akodionine (6), and one isocoumarin, akolitserin (7), together with seven known compounds, 8 - 14, were isolated from the AcOEt-soluble fraction of the fermentation broth of the endophytic fungus Xylaria cubensis, derived from the leaves of Litsea akoensis Hayata (Lauraceae). Their structures were elucidated by spectroscopic analyses, including 1D- and 2D-NMR experiments, and by HR-ESI-MS mass spectrometry. Among the isolates, (-)-(R)-7-hydroxymellein showed IL-6 inhibitory activity with an IC50 value of 9.41 mu m.