Fig. 3

a ¹³C tracing map from U-¹³C-Gln into the TCA cycle and derived metabolites (gray circles = ¹³C, white circle = ¹²C). b 1D HSQC representative spectrum of an IDH1^mut glioma cell line under DMSO (black) or CB839 (red) treatment displaying those resonances arising from ¹³C labeling from 72 h incubation in cell media containing ¹³C-U-Glutamine. c Intensities from isotopologues m+3 and m+5 of Glu under CB839 treatment (72 h) arising from ¹³C-Gln incorporation. ***p < 0.001. d ¹³C-Gln contribution to Asp (m+4), UDP (m+3) (e) and representative TCA cycle intermediates (m+4 isotopologues) (f). (n = 3, data displayed as mean ± SD; *p < 0.05; **p < 0.005; ***p < 0.001 from a t test). m+0, unlabeled; m+1, m+2, m+3, m+4, m+5, and m+6 represent the degree of m/z increase due to ¹³C labeling