Quantitative Analysis of Metabolic Mixtures by 2D 13C-Constant-Time TOCSY NMR Spectroscopy

Quantification of metabolite concentrations is a key task in metabolomics studies.

Significant peak overlaps in 1D NMR spectra of metabolomics samples prevent straightforward quantification through 1D peak integrals.Using uniformly 13C-labeled organisms, the 2D NMR 13C-13C constant-time (CT) TOCSY experiment provides high-resolution information about individual metabolites that allows their identification via database searching or, in the case of novel compounds, through the reconstruction of their backbone-carbon topology.

FSU researchers demonstrated how CT-TOCSY spectra can also be utilized for quantification purposes. The methods are demonstrated for carbohydrate and amino-acid mixtures.