Determination of Ion Structures in Structurally Related Compounds Using Precursor Ion Fingerprinting

Structurally-related alkaloids were analyzed by electrospray ionization/multiple stage mass spectrometry (ESI/MSn) at varying collision energies to demonstrate a conceptual algorithm, precursor ion fingerprinting (PIF). PIF is a new approach for interpreting and library-searching ESI mass spectra predicated on the precursor ions of structurally-related compounds and their matching product ion spectra. Multiple-stage mass spectra were compiled and constructed into “spectral trees” that illustrated the compounds' product ion spectra in their respective mass spectral stages. The precursor ions of these alkaloids were characterized and their spectral trees incorporated into an MSn library. These data will be used to construct a universal, searchable, and transferable library of MSn spectra. In addition, PIF will generate a proposed structural arrangement utilizing previously characterized ion structures, which will assist in the identification of unknown compounds.

Graphical AbstractPrecursor ion fingerprinting was utilized to create fragmentation trees for structurally-related alkaloids. These trees display the potential of PIF to identify of potential unknown compounds.Figure optionsDownload high-quality image (120 K)Download as PowerPoint slide