title: Improving natural products identification through targeted LC-MS/MS in an untargeted secondary metabolomics workflow.
abstract: Tandem mass spectrometry is a widely applied and highly sensitive technique for the discovery and characterization of microbial natural products such as secondary metabolites from myxobacteria. Here, a data mining workflow based on MS/MS precursor lists targeting only signals related to bacterial metabolism is established using LC-MS data of crude extracts from shaking flask fermentations. The devised method is not biased toward specific compound classes or structural features and is capable of increasing the information content of LC-MS/MS analyses by directing fragmentation events to signals of interest. The approach is thus contrary to typical auto-MS(2) setups where precursor ions are usually selected according to signal intensity, which is regarded as a drawback for metabolite discovery applications when samples contain many overlapping signals and the most intense signals do not necessarily represent compounds of interest. In line with this, the method described here achieves improved MS/MS scan coverage for low-abundance precursor ions not captured by auto-MS(2) experiments and thereby facilitates the search for new secondary metabolites in complex biological samples. To underpin the effectiveness of the approach, the identification and structure elucidation of two new myxobacterial secondary metabolite classes is reported.
authors.affiliation: Helmholtz Institute for Pharmaceutical Research Saarland, Helmholtz Centre for Infection Research and Department of Pharmaceutical Biotechnology, Saarland University , Building C 2.3, D-66123 Saarbrücken, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Hoffmann
authors.forename: Daniel
authors.initials: D
authors.lastname: Krug
authors.forename: Stephan
authors.initials: S
authors.lastname: Hüttel
authors.forename: Rolf
authors.initials: R
authors.lastname: Müller
mesh_terms: D001688:Biological Products / Q000737:chemistry*; D002853:Chromatography, Liquid / Q000379:methods*; D055432:Metabolomics; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D001688:Biological Products