Final ProgramCPSA 2011
Science and Technology Coming Together to Make a Difference
October 3 - 6, 2011
Bucks County Sheraton Hotel
Langhorne, PA
Poster Abstract #19
Overcoming the challenges in targeted and non-targeted metabolite profiling of myxobacterial secondary metabolites using UHR-Q-TOF-MS analysis
1) University of Saarbruecken, Saarbruecken, Germany; 2) Bruker Daltonik, Bremen, Germany
Introduction
Several secondary metabolites produced by Myxobacteria exhibit potent biological activities and are currently under investigation as potential leads for novel drugs. Hence, these bacteria are a promising source of natural products. However, the number of metabolites identified to date is significantly lower than expected from genome sequence information. Thus, the discovery of novel secondary metabolites from genetically proficient myxobacterial producers presents an on-going challenge.
Wildtype and mutant myxobacteria strains were analyzed to determine the production patterns of known metabolites and to discover new metabolites.
Data
Here, we present an ESI-UHR-Q-TOF based analysis of myxobacterial secondary metabolites, which enables several challenges frequently encountered in metabolite profiling studies to be solved. The challenges comprise the simultaneous need for fast, robust, and sensitive analysis with high resolution, accuracy and excellent reproducibility. Analytical solutions for targeted and non-targeted metabolomics experiments by means of ESI-UHR-Q-TOF-MS are discussed.
Since mass accuracy and resolution of TOF instruments are independent of the acquisition rate, they are perfectly suited for a coupling to U-HPLC separations. These hyphenations enable a reduction of analysis time in combination with high chromatographic resolution and therefore increasing sample throughput. Acquisition rates of up to 20Hz were achieved without any compromise in mass accuracy or resolution.
Targeted and non-targeted metabolite profiling: Acquisition of full scan accurate mass spectra enable the targeted screening of known compounds e.g. from the class of DKxanthenes based on very selective, high resolution EIC (hrEIC) traces with small mass windows of 1.0 - 0.5 mDa. A comparison of several datasets following a comprehensive extraction of molecular features combined with statistical analysis enabled the discovery of novel biomarkers using a non-targeted approach from the same data files used for the targeted analysis.
Identification
Mass accuracies of 0.1 ppm are often not sufficient for unambiguous formula identification for m/z values above 500. A combination of accurate mass data and isotopic pattern information in MS and MS/MS spectra can extend this m/z range for reliable formula suggestions. The mteabolites (?) Myxalamid A and DK-Xanthen-548 were identified using this approach as compounds that differ in abundance between the myxobacterial strains analysed in this study.