TABLE 3.
Metabolomic features differing by meal challenge in top pathways1
| Feature | xMSannotator3 | Annotation score | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Pathway2 | m/z | RT, s | Adduct | Log2 peak area (median; IQR) | Concentration, μM (median; IQR)4 | Column | Chemical compound | Formula | HMDB monoisotopic mass | HMDB ID | xMSannotator confidence score | In-house reference library | MSI level |
| Linoleic acid metabolism | 281.2473 | 25.6 | M + H | 16.71 (16.28, 17.14) | — | HILIC+ | Linoleic acid | C18H32O2 | 280.24023 | HMDB00673 | 3 | ✓ | 2 |
| 279.2335 | 235.8 | M-H | 30.19 (29.55, 30.79) | 7820.72 (5194.41, 11,637.75) | C18− | Linoleic acid | C18H32O2 | 280.24023 | HMDB00673 | 3 | ✓ | 2 | |
| Primary bile acid synthesis | 124.0073 | 24.3 | M-H | 20.51 (20.19, 20.85) | 7.12 (5.85, 8.74) | C18− | Taurine | C2H7NO3S | 125.014664 | HMDB00251 | 3 | ✓ | 2 |
| 407.2812 | 29.8 | M-H | 14.93 (7.02, 16.51) | 0.03 (0.02, 0.08) | C18− | Cholic acid | C24H40O5 | 408.287574 | HMDB00619 | 3 | — | 3 | |
| 433.3329 | 235.3 | M-H | 14.73 (13.72, 15.51) | — | C18− | 3α,7α-Dihydroxycoprostanic acid | C27H46O4 | 434.33961 | HMDB00359 | 2 | — | 3 | |
| 433.3329 | 235.3 | M-H | 14.73 (13.72, 15.51) | — | C18− | 3α,7α,12α-Trihydroxy-5β-cholestan-26-al | C27H46O4 | 434.33961 | HMDB03533 | 2 | — | 3 | |
| TCA cycle | 115.004 | 18.8 | M-H | 16.99 (16.35, 17.35) | 14.81 (11.65, 18.65) | C18− | Fumaric acid | C4H4O4 | 116.010959 | HMDB00134 | 2 | ✓ | 3 |
| 133.0143 | 21.9 | M-H | 20.41 (19.46, 21.05) | 4.67 (3.11, 6.11) | C18− | l-Malic acid | C4H6O5 | 134.021523 | HMDB00156 | 3 | ✓ | 2 | |
| 145.0143 | 20.6 | M-H | 21.80 (20.85, 22.39) | — | C18− | Oxoglutaric acid | C5H6O5 | 146.021523 | HMDB00208 | 2 | — | 3 | |
| 145.0982 | 28.2 | M-H | 16.83 (14.23, 17.65) | 176.31 (130.17, 264.13) | C18− | l-Lysine | C6H14N2O2 | 146.105528 | HMDB00182 | 2 | ✓ | 3 | |
| 173.0085 | 23.2 | M-H2O-H | 19.91 (19.37, 20.49) | — | C18− | Citric acid | C6H8O7 | 192.027003 | HMDB00094 | 3 | — | 3 | |
| 191.0199 | 22.4 | M-H | 24.37 (23.90, 24.87) | 286.35 (184.76, 416.27) | C18− | Citric acid | C6H8O7 | 192.027003 | HMDB00094 | 3 | — | 3 | |
C18-, C18 column with negative electrospray ionization; GSEA, gene set enrichment analysis; H, hydrogen; HILIC+, hydrophilic interaction liquid chromatography column with positive electrospray ionization; HMDB, Human Metabolome Database; KEGG, Kyoto Encyclopedia of Genes and Genomes; M, analyte molecule; MSI, Metabolomics Standards Initiative; RT, retention time; TCA, tricarboxylic acid.
Top pathways based on mummichog and GSEA algorithms (Pcombined < 0.05) in MetaboAnalystR (mummichog, v 1.0).
Features in top pathways. Annotations based on feature matches in KEGG (mummichog) and HMDB (xMSannotator).
Concentrations calculated based on the observed feature peak area, Q-std3 peak area, and known metabolite concentration. Only among features that matched with available calibrated reference data for metabolite.