Hetiamacin E and F, New Amicoumacin Antibiotics from Bacillus subtilis PJS Using MS/MS-Based Molecular Networking.To combat escalating levels of antibiotic resistance, novel strategies are developed to address the everlasting demand for new antibiotics.  This study aimed at investigating amicoumacin antibiotics from the desert-derived Bacillus subtilis PJS by using the modern MS/MS-based molecular networking approach. 
MS/MS
The planar structures were determined by analysis of extensive NMR spectroscopic and HR-ESI-MS data, and the absolute configurations were concluded by analysis of the CD spectrum. 
HR-ESI-MS