SIRIUS and beyond: Turning tandem mass spectra into metabolite structure information

Liquid Chromatography Mass Spectrometry is a highly sensitive experimental platform for the analysis of metabolites and other small molecules. Unfortunately, structural elucidation of metabolites from tandem MS data remains highly challenging; in untargeted metabolomics experiments, only a small percentage of spectra can be annotated via spectral libraries. For more than a decade, my group has been developing computational solutions for this task. In my talk, I will focus on three aspects of our work: Firstly, how to annotate metabolite MS/MS spectra using fragmentation trees via SIRIUS; second, how to search a MS/MS spectrum in a molecular structure database via CSI:FingerID; and third, how to assign thousands of compound classes to each spectrum even when the compound is missing from all structural and spectral databases (CANOPUS). I will also quickly touch upon assigning confidence search results in a molecular structure database via COSMIC, lipid analysis with El Gordo, and combinatorial fragmentation with Epimetheus.