Multiple bond 13C-13C spin-spin coupling provides complementary information in a 13C NMR isotopomer analysis of glutamate

Magn Reson Med. 1999 Jul;42(1):197-200. doi: 10.1002/(sici)1522-2594(199907)42:1<197::aid-mrm26>;2-5.


Most 13C nuclear magnetic resonance (NMR) isotopomer analyses relate a metabolic index of interest to populations of 13C isotopomers as reported by one-bond 13C-13C spin-spin couplings. Metabolic conditions that produce highly enriched citric acid cycle intermediates often lead to 13C NMR spectra of metabolites such as glutamate that show extra multiplets due to long-range couplings. It can be demonstrated from 13C NMR spectra of hearts perfused with mixtures of acetate plus propionate that multiplets in glutamate C2 arising from 3J25 coupling provide a direct readout of acetyl-CoA fractional enrichment (FC1 and FC3), while multiplets in glutamate C5 arising from 2J35 and 3J25 couplings quantitatively reflect enrichment of the anaplerotic substrate.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Carbon Isotopes
  • Fourier Analysis
  • Glutamic Acid / metabolism*
  • Humans
  • Magnetic Resonance Spectroscopy / instrumentation*
  • Myocardium / metabolism*
  • Sensitivity and Specificity
  • Signal Processing, Computer-Assisted / instrumentation*
  • Spin Labels*


  • Carbon Isotopes
  • Spin Labels
  • Glutamic Acid