File Entry: Automated Workflows for Accurate Mass-based Putative Metabolite Identification in LC/MS-derived Metabolomic Datasets

Three workflows, together defined as PUTMEDID-LCMS, have been developed using the open source Taverna environment to perform putative metabolite identification based on accurate mass data acquired from liquid chromatography-electrospray mass spectrometry instruments. Three workflows perform the following steps. (Step 1) Generation of a list of pairwise peak correlations required for input to workflow 2 (workflow 1) (Step 2) Annotation of features to group different ion types of the same metabolite based on mass differences, similar retention times and correlation coefficient between peak responses (workflow 2). (Step 3) Matching of accurate m/z to the accurate mass of neutral molecules and associated molecular formula in a reference file within a specified mass tolerance (workflow 2). (Step 4) Matching of the molecular formulae to a reference file of metabolites (workflow 3). The parameters employed in all workflows are user defined and can be optimized for particular datasets or instruments. The workflows have been validated with multiple sample types including intracellular extracts of yeast and human biofluids (urine and serum).(http://www.mcisb.org/resources/putmedid.html).