Unknown Compound Identification

Schematic workflow of metabolite identification by LC-ESI-MS/MS analysis. Known molecular determination results from database search whereas unknown structure elucidation requires interpretation of the gas-phase fragmentation reactions.

Untargeted metabolomics play a fundamental role in allowing the interrogation of metabolic disorders for the purposes of biomarker discovery and generating new metabolic hypothesis. Still, the chemical diversity of complex biological systems makes it remarkably difficult to accurately unravel their metabolite constitution. Proof of this is given by one recent study that points to the fact that only 1.8% of molecules detected untargeted metabolomics experiment can have their identities known.

While computational solutions are being developing for the untargeted characterization of metabolites, using MS and NMR approaches, we offer algorithm- and manual-based approaches for accurate molecular identification in complex biological samples. We apply high-resolution HPLC-ESI-MS/MS experiments coupled with collision induced dissociation methodologies to selectively induce fragmentation of selected ions in the gas-phase, followed by the systematic examination of the fragmentation reactions rationalized according to organic chemistry principles. 1D and 2D NMR techniques are applied to the structure elucidation.


    • Carnevale Neto, F.; Andréo, M. A.; Raftery, D.; Lopes, J. L. C.; Lopes, N. P.; Castro-Gamboa, I.; Lameiro de Noronha Sales Maia, B. H.; Costa, E. V.; Vessecchi, R. Characterization of Aporphine Alkaloids by Electrospray Ionization Tandem Mass Spectrometry and Density Functional Theory Calculations. Rapid Commun. Mass Spectrom. 34(S3):e8533, 2020. https://doi.org/10.1002/rcm.8533.