<p>Four previously undescribed isochromanes were isolated from the fermentation broth of an endophytic fungus <i>Aspergillus fumigatus</i>, which was obtained from the fruiting body of <i>Cordyceps sinensis</i>. Their structures were elucidated through extensive spectroscopic analyses. One racemic isochromane was further purified by chiral HPLC to yield a pair of enantiomers and their absolute configurations were determined by quantum chemical ECD calculations. These isolated compounds were evaluated for cytotoxicity against two cell lines (MV4-11 and MDA-ME-231) and the result showed that compounds <b>1a</b> and <b>2</b> exhibited moderate growth inhibition against MV4-11 cell line.</p
