Customized Metabolomics Database for the Analysis of NMR (1)H–(1)H TOCSY and (13)C–(1)H HSQC-TOCSY Spectra of Complex Mixtures

[Image: see text] A customized metabolomics NMR database, termed (1)H((13)C)-TOCCATA, is introduced, which contains complete (1)H and (13)C chemical shift information on individual spin systems and isomeric states of common metabolites. Since this information directly corresponds to cross sections of 2D (1)H–(1)H TOCSY and 2D (13)C–(1)H HSQC-TOCSY spectra, it allows the straightforward and unambiguous identification of metabolites of complex metabolic mixtures at (13)C natural abundance from these types of experiments. The (1)H((13)C)-TOCCATA database, which is complementary to the previously introduced TOCCATA database for the analysis of uniformly (13)C-labeled compounds, currently contains 455 metabolites, and it can be used through a publicly accessible web portal. We demonstrate its performance by applying it to 2D (1)H–(1)H TOCSY and 2D (13)C–(1)H HSQC-TOCSY spectra of a cell lysate from E. coli, which yields a substantial improvement over other databases, as well as 1D NMR-based approaches, in the number of compounds that can be correctly identified with high confidence.