of the structures (Table ). SIRIUS supports only singly charged ions with MS 2 information, so thiostreptone (Table ) and epemicin A (Table ) could not be computed, since only their doubly charged adduct was fragmented. Finally, the spectral matching step complemented the structural predictions with annotations for the germicidins A and B, kirromycin and siderophores of the desferrioxamine pathway (Table -10), reaching to a total of 65% accurate structural annotations.