Structure of Potential Dithiolopyrrolone Antibiotics Detected from the DART-ToF-MS Spectra of Saccharothrix algeriensis Extract

Dithiolopyrrolone antibiotics, produced by the Saharan mycelial bacterium Saccharothrix algeriensis , are known for their potent biological activities. Biochemical profiling of S. algeriensis culture extract was done by direct analysis in real time and time-of-flight mass spectrometry (DART-ToF-MS). No other study on dithiolopyrrolones by this technique has been published. Eleven dithiolopyrrolone derivatives: thiolutin, butyryl-pyrrothine/iso-butyryl-pyrrothine, senecioyl-pyrrothine/tigloyl-pyrroth-ine, valeryl-pyrrothine/iso-valeryl-pyrrothine, 2-methyl-3-pentenyl-pyrrothine/2-hexonyl-pyrrothine, iso-hexanoyl-pyrrothine and benzoyl-pyrrothine were characterised by their exact mass measurement and the corresponding molecular formula of each compound. The obtained results confirmed that DART-ToF-MS is an appropriate confirmatory technique for powerful and rapid screening, as well as characterisation of bacterial secondary metabolites.