ANYL 192 |
| Comprehensive analyses of small molecule metabolites can provide important insight into biological systems. The desired outcomes of such metabolomics studies are the detection, identification, and precise quantification of a large number of metabolites with diverse chemical structures and broad concentration ranges. A precise quantitative comparison of many analytes between two or more samples is readily accomplished by employing a chemically identical but isotopically distinct labeling reagent for each sample. After the labeling reactions, the samples are mixed and then analyzed by LC-MS. This approach has been widely used in proteomics (e.g. isotope-coded affinity tags), but it has seen minimal use in metabolomics, partly due to the lack of a common functional group present in all metabolites to act as the target for the labeling chemistry. We envision a small set of labeling reagents that target the most prevalent functional groups in the metabolome. Here, we report some examples of such labeling reagents, two for amine-containing metabolites and one for carboxylic acids. The reagents require minimal cleanup after the labeling reaction, have limited impact on LC retention time, and enhance sensitivity in positive-mode electrospray ionization mass spectrometry. We describe the synthesis and use of heavy and light isotopic forms of these reagents for relative quantification in metabolomics experiments involving Arabidopsis thaliana. |
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Development and Applications of Metabonomic/Metabolomic Methods of Analysis
8:30 AM-11:35 AM, Monday, 11 September 2006 Moscone Center -- Room 124, Oral
Division of Analytical Chemistry |