Fig. 1From: MassSpecBlocks: a web-based tool to create building blocks and sequences of nonribosomal peptides and polyketides for tandem mass spectra analysisThe structure, building blocks, and fragmentation of linear polyketide siderophore desferrioxamine B. The nominal masses of fragment ions are reported. Because the molecule has two N-termini, we use the letters L (left) and R (right) to distinguish between the two series of b-ionsBack to article page