Terretonin O: a new meroterpenoid from <i>Aspergillus terreus</i>

Abstract

Terretonin O (<b>1</b>), a new meroterpenoid, was isolated individually from both methanolic extracts of thermophilic <i>Aspergillus terreus</i> TM8 and marine <i>Aspergillus terreus</i> LGO13. The recently reported terretonins M (<b>2</b>) and N (<b>3)</b> were further isolated from the fungus LGO13 along with nine known compounds, terrelumamide A (<b>4</b>), terrein (<b>5</b>), methyl-3,4,5-trimethoxyl-2-[2-(nicotinamide)benzamido] benzoate (<b>6</b>), butyrolactones I-III (<b>7</b>-<b>9</b>), aspulvinone O (<b>10</b>), ergosterol, ergost-4-ene-3-one and methyl linoleate. Structure of terretonin O (<b>1</b>) was established on the bases of HRESIMS, 1D and 2D NMR spectra and comparison with its analogues in literatures. The relative stereochemistry of <b>1</b> was assigned on the basis of NOESY spectra and comparison with reported configuration of its congener compounds <b>2</b> and <b>3</b>. The antimicrobial and cytotoxic activities of the fungal extracts and obtained compounds were assayed using a set of microorganisms, and cervix carcinoma cell line (KB-3-1), respectively. Isolation and taxonomical characterization of the producing strains are reported.