(A) Representative multiplicity edited HSQC from the polar fraction of a Hs 766T xenograft. The sign of the peak is reflective of the proton connectivity of the carbon: positive peaks (red) arise from functional groups with an odd number of hydrogens such as methine (CH) and methyl (CH3) groups, while signals with negative peaks (blue) arise from carbons with an even number of hydrogens such as quaternary (C) and methylene (CH2) groups. Major resonances are assigned as follows Glc*=glucose, Lac*=lactate, Ala*=alanine, Asp*=aspartic acid, Glx*=glutamate/glutamine, Glyc = glycerol containing, Chol = choline containing. Peaks originating from the 13C glucose bolus are identified by the presence of 13C coupling and marked with an *. (B) 13C satellites for the primary downstream metabolites lactate, alanine, and glutamate. The vertical and horizontal lines represent 13C12C and 12C13C coupling, respectively, and indicate metabolic scrambling from unlabeled precursors. The dashed red vertical line shows a crosspeak of Thr that overlaps with lactate in the 1D proton spectrum.