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Updated: Aug 9, 2026

Metabolic Pathway Confirmation and Discovery Through 13C-labeling of Proteinogenic Amino Acids
Published on: January 26, 2012
Innovations in generation and analysis of 2D [(13)C,(1)H] COSY NMR spectra for metabolic flux analysis purposes
W van Winden1, D Schipper, P Verheijen
1Bioprocestechnology Group, Faculty of Applied Sciences, Delft University of Technology, Julianalaan 67, 2628 BC Delft, The Netherlands. W.A.VanWinden@tnw.tudelft.nl
Abstract:
2D [(13)C,(1)H] COSY NMR is used by the metabolic engineering community for determining (13)C-(13)C connectivities in intracellular compounds that contain information regarding the steady-state fluxes in cellular metabolism. This paper proposes innovations in the generation and analysis of these specific NMR spectra. These include a computer tool that allows accurate determination of the relative peak areas and their complete covariance matrices even in very complex spectra. Additionally, a method is introduced for correcting the results for isotopic non-steady-state conditions. The proposed methods were applied to measured 2D [(13)C,(1)H] COSY NMR spectra. Peak intensities in a one-dimensional section of the spectrum are frequently not representative for relative peak volumes in the two-dimensional spectrum. It is shown that for some spectra a significant amount of additional information can be gained from long-range (13)C-(13)C scalar couplings in 2D [(13)C,(1)H] COSY NMR spectra. Finally, the NMR resolution enhancement by dissolving amino acid derivatives in a nonpolar solvent is demonstrated.
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