Cytotoxic and antimicrobial benzodiazepine and phenolic metabolites from Aspergillus ostianus IMBC-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 1 (4), cycloanthranilylproline (5), and (11a5)-2,3-dihydro-7-methoxy-1H-pyrrolo[2,1- c][1,4]benzodiazepine-5,11(10H,11a/f)-dione (6), 4-hydroxybenzoic acid (7), and syringaldehyde (8) by spectroscopic methods, including ID 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 Emerococcus faecalis and Candida albicans, with MIC values ranging from 18.7-100 µM.