Cytotoxic and antimicrobial benzodiazepine and phenolic metabolites from Aspergillus ostianusIMBC‐NMTP03

Abstract

Six benzodiazepine alkaloids and two phenolics were isolated from an ethyl acetate extract of the fungal strain Aspergillus ostianus IMBC‐NMTP03 fermentation culture. Their chemical structures were elucidated as circumdatins D (1), E (2), J (3), and I (4), cycloanthranilylproline (5), and (11aS)‐2,3‐dihydro‐7‐methoxy‐1H‐pyrrolo[2,1‐c][1,4]benzodiazepine‐5,11(10H,11aH)‐dione (6), 4‐hydroxybenzoic acid (7), and syringaldehyde (8) by spectroscopic methods, including 1D and 2D NMR and mass spectra in comparison with the literature data. Compounds 2, 4, and 5 showed cytotoxicity toward KB, MCF‐7, and LNCaP cancer cell lines (41.14‐49.76 % cell death) while 7 was cytotoxic against HL‐60, KB and LNCaP cells (41.77‐47.06 % cell death). Compounds 1‐3 and 5‐8 displayed antimicrobial activity against Enterococcus faecalis and Candida albicans, with MIC values ranging from 18.7‐100 μM.