Chemical investigation of metabolites produced by an endophytic <i>Aspergillus</i> sp. isolated from <i>Limonia acidissima</i>

<div><p>Endophytic fungi are considered as a good source to produce important secondary metabolites with interesting bioactivities. In a continuation of our studies towards the search for environmentally friendly bioactive compounds from Sri Lankan flora, we investigated the secondary metabolites produced by the endophytic fungi <i>Aspergillus sp.</i> isolated from the seeds of the popular edible fruit <i>Limonia acidissima</i> L. of the family Rutaceae. The pure culture of the <i>Aspergillus</i> sp. was grown on potato dextrose broth media. After 4 weeks fermentation, fungal media were extracted with organic solvents. Chromatographic separation of the fungal extracts over silica gel, Sephadex LH-20 and RP-HPLC furnished flavasperone (<b>1</b>), rubrofusarin B (<b>2</b>), aurasperone A (<b>3</b>), fonsecinone D (<b>4</b>) and aurasperone B (<b>5</b>). Compounds <b>1</b>–<b>4</b> showed moderate activities in brine shrimp toxicity assay. This is the first report of the ¹³C NMR data of compounds <b>4</b> and <b>5</b>.</p></div