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Determination of ion structures in structurally related compounds using precursor ion fingerprinting
Michelle T Sheldon1, Robert Mistrik, Timothy R Croley
1Commonwealth of Virginia, Department of General Services, Division of Consolidated Laboratory Services, Richmond, Virginia 23219, USA.
Journal of the American Society for Mass Spectrometry
|December 2, 2008
Summary
Precursor ion fingerprinting (PIF) uses mass spectrometry to identify alkaloids by analyzing related compounds and their fragment ions. This method builds a searchable library for unknown compound identification.
Area of Science:
- Analytical Chemistry
- Mass Spectrometry
- Organic Chemistry
Background:
- Electrospray ionization/multiple stage mass spectrometry (ESI/MS(n)) is crucial for analyzing complex mixtures.
- Identifying structurally similar compounds requires advanced spectral interpretation techniques.
- Current mass spectral libraries may lack comprehensive data for novel compound classes.
Purpose of the Study:
- To introduce and validate a novel algorithm, precursor ion fingerprinting (PIF), for interpreting and searching electrospray ionization mass spectra.
- To demonstrate the utility of PIF in analyzing structurally-related alkaloids.
- To lay the groundwork for a universal, searchable, and transferable library of MS(n) spectra.
Main Methods:
- Analysis of structurally-related alkaloids using electrospray ionization/multiple stage mass spectrometry (ESI/MS(n)) at varied collision energies.
- Development of a conceptual algorithm, precursor ion fingerprinting (PIF), based on precursor ion characteristics and product ion spectra.
- Construction of "spectral trees" to visualize compound fragmentation patterns across multiple MS stages.
- Characterization of precursor ions and incorporation of spectral trees into an MS(n) library.
Main Results:
- Demonstration of the precursor ion fingerprinting (PIF) algorithm's capability to interpret ESI mass spectra.
- Successful characterization of precursor ions for a set of structurally-related alkaloids.
- Compilation of MS(n) spectral data into "spectral trees" for library construction.
- Generation of proposed structural arrangements for compounds based on characterized ion structures.
Conclusions:
- Precursor ion fingerprinting (PIF) offers a new approach for interpreting and library-searching ESI mass spectra.
- The developed method facilitates the identification of unknown compounds by leveraging spectral trees and characterized ion structures.
- The study establishes a foundation for creating a universal and transferable MS(n) spectral library.
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