Extended Data Fig. 3: Fractional 18O labelling of metabolites and features identified in human cells by 18O2 labelling.
From: The polar oxy-metabolome reveals the 4-hydroxymandelate CoQ10 synthesis pathway
a, Heatmap representing the median fractional 18O labelling of the 46 metabolites and features in the indicated cell lines and oxygen tensions. “**” represents metabolites that have matching MS2 spectra, but need to be validated due to multiple metabolite isomers. The red arrow indicates a highly labelled unknown metabolite. b, Correlation matrixes demonstrating the Spearman rs value based on the fractional 18O labelling of the 46 metabolites and features across the indicated cell lines and oxygen tensions. c, Fractional 18O labelling of unknown feature (167.0339 in negative ion mode, elution time of 8.2 min) in MIAPACA2, A498, and SKNDZ cells grown in 3%, 1%, and 0.2% 18O2, and treated with vehicle or IOX1 (dioxygenase inhibitor) for 24 h (n = 3). d–i, Fractional 18O labelling of metabolites and features by 18O2 across multiple cell lines in response to different oxygen tensions, treated with or without IOX1 (dioxygenase inhibitor) for 24 h. 18O labelling of predicted (d, e), not predicted (f–h), and unknown (i) metabolites or features are shown for the indicated cell line. ** represents metabolites that have matching MS2 spectra, but need to be validated due to multiple metabolite isomers. n = 3 biologically independent samples for each group and condition in all experiments. Graphs represent mean ± s.e.m. and were compared using one- (b–d) or two-way ANOVA (a, e, f), followed by Tukey post hoc test (*P < 0.05, ^P < 0.01, %P < 0.005, #P < 0.0001).
