Sedoheptulose-1,7-bisphospate Accumulation and Metabolic Anomalies in Hepatoma Cells Exposed to Oxidative Stress

Figure 2

Oxidative stress-induced accumulation of Fru-1,6-BP and S-1,7-BP. The extracted ion chromatograms of Fru-1,6-BP (a) and S-1,7-BP (b) in Hep G2 cell treated with 5 mM H₂O₂ for 0, 15, 30, 60, 90, and 120 min are shown. Metabolite abundance is indicated by the peak intensity. A representative experiment is shown. The identities of Fru-1,6-BP (c, d) and S-1,7-BP (e) were validated by MS/MS analysis. The MS/MS spectrum of Fru-1,6-BP in cell specimen (d) was matched against that of standard (c). The spectrum of S-1,7-BP reveals a parent cation (369.0001 m/z) and a fragment ion (271.0227 m/z). The latter differs from the fragment ion of Fru-1,6-BP (241.0125 m/z) by a CHOH unit (30.01 m/z). For (c–e), the chemical structures of the fragment ions and their experimentally obtained m/z values are shown alongside the corresponding peaks.