Xylaropyrones B and C, new γ-pyrones from the endophytic fungus <i>Xylaria</i> sp. SC1440

<p>Two new γ-pyrones, xylaropyrones B (<b>1</b>) and C (<b>2</b>), together with three known compounds, xylaropyrone (<b>3</b>), annularin A (<b>4</b>) and annularin C (<b>5</b>), were isolated from solid cultures of the endophytic fungus <i>Xylaria</i> sp. SC1440. The structures of these compounds were determined mainly by analysis of their NMR spectroscopic data. The relative configurations of <b>1</b> and <b>2</b> were assigned on the basis of <i>J</i>-based configurational analysis, and the absolute configurations were established by experimental and TDDFT calculated ECD spectra. The isolated compounds were evaluated for cytotoxic and tyrosinase inhibitory activity.</p>