Metabolomics in Analytical Chemistry
other creative enhancements enable a range of novel metabolomic measurements. Applications range from investigating the metabolome of blood, urine, and tissues, which relate metabolic proﬁles to disease and health, to stretching to include microbes, plants, and foods. For me, one of the most exciting areas is downscaling the measurements to the individual cell level (detailed in 2011 in the Feature by Svatos, “Single-cell metabolomics comes of age: new developments in mass spectrometry proﬁling and imaging” (DOI 10.1021/ac2003592) and the Review by Lin et al., “Chemical Analysis of Single Cells” (DOI 10.1021/ ac2009838). Single cell measurements provide an unprecedented opportunity to observe how changes in the small molecule complement track cell activity and physiology. Because the articles selected for this issue represent only about 10% of the total metabolomics manuscripts published in Analytical Chemistry in the 2008−2011 period, I apologize to the authors whose work was not included, and I encourage readers to look beyond this list at this vibrant subﬁeld covered by Analytical Chemistry. While further advances in training, databases, and technologies are needed, the ﬁeld of analytical chemistry is meeting the challenge by enabling metabolomics to rise to its full potential.
e are in the age of -omics and systems biology, and so it is not surprising that many articles published in Analytical Chemistry describe advances in measurements related to the genome, proteome, and metabolome. To highlight one of these important areas, metabolomics, we now bring you a special virtual issue including some of the exciting advances that have been published in the journal. Genomics can be considered the original -omics as it was one of the ﬁrst concerted global eﬀorts to create a complete listing of one category of the molecules of life used by an organism. Measuring the protein content soon followed, and based on the exciting proteomics work that has been published in Analytical Chemistry, this is certainly an active area of research. Metabolomics is both the oldest and newest of the classical -omics. Oldest in that measuring the small molecules found in a body ﬂuid, tissue, or even a plant seed dates back more than one hundred years, before genes and proteins were even known; newest in that there has yet to be a complete listing of the small molecules present in an organism. Of course, technologies such as nuclear magnetic resonance (NMR) and mass spectrometry (MS) have advanced to the point where the wholesale characterization of hundreds to thousands of metabolites in a sample is on the verge of becoming routine. The metabolome of a cell or tissue yields critical information on its physiological status, and as it presents the output of many interconnected pathways, it has been considered a more telling indicator of a cell or organism’s functional state. Earlier in 2012, the U.S. National Institutes of Health’s Common Fund recognized both the importance of the metabolome for understanding health and disease and the unmet challenges by announcing a program to fund metabolomic research eﬀorts and technologies. Although it may not yet be possible to completely characterize the metabolome, seminal advances have been reported in Analytical Chemistry that describe how to close the gap on what is needed and what is measurable. Many important and innovative manuscripts have appeared and hopefully will continue to appear in Analytical Chemistry, even as specialized journals are launched in this active ﬁeld. In fact, between 2008 and 2011, more than 300 articles on various forms of metabolomics, metabonomics, and global metabolic proﬁling appeared in Analytical Chemistry. Based on the subtleties of what has been measured, a variety of terminology is used, and this variety has been used in generating the lists of manuscripts to include in this virtual issue. The goal here is to highlight about 30 articles that represent the breadth of modern metabolomics and the advances that have been made. NMR plays a large role given its ability to identify and quantitate hundreds of metabolites from a complex sample. Thus, you will ﬁnd articles on new NMR technologies, pulse sequences, databases, statistical approaches, and sampling enhancements. Similarly, advances in MS include new mass analyzers, ionization methods, compound databases, statistical approaches, and sampling protocols. Fractionation and separations are also key areas, and not surprisingly, improving hyphenations such as those between MS and capillary electrophoresis are another active area. MS imaging of tissues and © 2012 American Chemical Society
Jonathan V. Sweedler
Published: June 25, 2012 5833
dx.doi.org/10.1021/ac301554c | Anal. Chem. 2012, 84, 5833−5833