Final ProgramCPSA 2011
Science and Technology Coming Together to Make a Difference
October 3 - 6, 2011
Bucks County Sheraton Hotel
Langhorne, PA
Poster Abstract #24
High-resolution accurate mass-measurements and metabolite identification: an automated approach using fragment prediction in combination with fragment ion search (FISh)
1) Swiss BioAnalytics AG, Birsfelden, Switzerland, 2) Thermo Fisher Scientific, San Jose CA, USA
A novel metabolite screening and identification process combining high-resolution and accurate-mass data in combination with novel software-tools has been outlined. In order to evaluate an automated and software-driven pathway for metabolite screening and identification we processed high-resolution accurate mass data using the fragment ion search approach (FISh-approach) of the software Mass Frontier 7.0 (Thermo Fisher Scientific). Data-Dependent-MSn-data (n = 2-3) was used for component detection and identification based on theoretically calculated fragments of the metabolite structures. The investigated metabolites were derived from Ticlopidine, a drug which is known be extensively metabolized. Ticlopidine was incubated with human liver S9 enzymes at 10 µM Ticlopidine, 3mM NADPH, and 3 mM S-Adenosyl-L-methionine chloride. Aliquots of the reaction solution were withdrawn at consecutive time points and the reaction was stopped by the addition of ACN. Analyses were performed on a LTQ-Orbitrap XL mass spectrometer. High-resolution accurate-mass data was directly exported to the Mass Frontier 7.0 software. After the automated removal of noise and baseline signals and the theoretical calculation of possible fragments of Ticlopidine, a general list of possible phase I and II biotransformation was applied and the LC-MS chromatogram was processed by a component detection algorithm. Fragment ion search (FISh) was then used to screen the detected components and the corresponding spectral trees to identify putative metabolites of Ticlopidine. The FISh approach was able to generate possible structures of metabolites by displaying the relationship between detected components with the matched m/z values and the corresponding fragment structures based on the calculated fragments of Ticlopidine. In order to control the quality of our results and to test the recovery of the automated FISh process in biological fluids, we add individual samples to different biological matrices and compared the final results in terms of spectral quality, detection of possible metabolites and proposed structures of the metabolites.
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