Seven sesquiterpenoids, named nebucanes A-G (<b>1</b>-<b>7</b>), featuring a rare alliacane scaffold with unprecedented furan or pyrrole functions, were isolated from the fermentation broth of <i>Clitocybe nebularis</i>. Their structures were established on the basis of 1D/2D NMR spectroscopic analyses, HR-(+)-ESIMS spectra, and comparison of measured and calculated CD spectra for determination of the absolute configuration. Assessing the biological activities, nebucane D (<b>4</b>) exhibited antifungal effects against <i>Rhodotorula glutinis</i>, while nebucane G (<b>7</b>) displayed significant cytotoxicity against MCF-7 and A431 cell lines.