Fig. 2

Metabolism of [5-¹³C] glutamine to [5-¹³C] glutamate. a Time-dependent spectral data following conversion of [5-¹³C] glutamine to [5-¹³C] glutamate. The signals are from ¹³C-enriched [5-¹³C]glutamate at 181.5 ppm and [5-¹³C]glutamine at 178.5 ppm and from natural abundance ¹³C label in [1-¹³C]glutamate at 175.2 ppm and [1-¹³C]glutamine at 174.7 ppm. b Plot of the ratio of the signal intensities of [5-¹³C]glutamate/[5-¹³C]glutamine showing the ratio in hepatoma cells (shaded circle), cell lysate (square), and control (triangle). These results demonstrated that hepatoma cancer cells convert glutamine to glutamine at a higher rate than normal cells. Adapted with permission from ref. [49]