Heptacyclic oligophenalenones from the soil fungus Talaromyces bacillisporus BCC17645

Abstract Four new oxaphenalenone dimers (bacillisporins I and J, duclauxamides B and C) together with four known compounds (bacillisporins A – C and duclauxamide A1) were isolated from the soil fungus Talaromyces bacillisporus BCC17645. Duclauxamides B and C were the rare N-containing oxaphenalenone dimers isolated from this fungus. Chemical structures were determined based on the evidence from NMR spectral information and mass spectral analysis. Their absolute configurations were identified by comparison of CD spectra with the related compounds. These isolated compounds exhibited broad antibacterial activity against Mycobacterium tuberculosis H37Ra, Bacillus cereus, and Staphylococcus aureus with MIC values in a range of 3.13 – >50 μg/mL and also had low cytotoxicity against both cancerous (MCF-7 and NCI–H187) and non-cancerous (Vero) cells.