Table 1.
Validated biomarkers and MS/MS fragments
| Metabolite | Adduct | Ret. time | m/z Found (Precursor) | m/z Predicted | ppm error | MS/MS fragments | Major Metabolic Pathway Involvement | ||
|---|---|---|---|---|---|---|---|---|---|
| Fragment 1 | Fragment 2 | Fragment 3 | |||||||
| Riboflavin | [M+Na]+ | 2.91 | 399.1283 | 399.1275 | 2.0 | 359.1323 | 243.088 | 158.9626 | Riboflavin metabolism |
| Kynurenic acid | [M+H]+ | 1.45 | 190.0504 | 190.0499 | 2.6 | 172.0407 | 144.0456 | 116.0511 | Tryptophan metabolism |
| Xanthurenic acid | [M+H]+ | 1.19 | 206.0453 | 206.0448 | 2.5 | 188.0336 | 160.0382 | 132.0435 | Tryptophan metabolism |
| 5′-Deoxy-5′-Methylthioadenosine | [M+H]+ | 1.32 | 298.0981 | 298.0968 | 4.4 | 136.0616 | 119.0354 | - | Cysteine and methionine metabolism |
| Pantothenic acid | [M+H]+ | 0.79 | 220.1184 | 220.1180 | 2.0 | 202.1071 | 184.0965 | 90.0553 | beta-alainine metabolism, pantothenate and CoA biosynthesis |
| Uric acid | [M−H]− | 0.35 | 167.0208 | 167.0211 | 1.8 | 124.0147 | 96.0203 | 69.0097 | Purine metabolism |
| 2-Oxoadipic acid | [M−H]− | 0.39 | 159.0302 | 159.0299 | 1.9 | 115.0404 | 87.0459 | 59.015 | Lysine biosynthesis, tryptophan metabolism |
| D-Ribose | [M-H]− | 0.34 | 149.0451 | 149.045 | 0.7 | 89.0239 | 71.0143 | 59.0137 | Pentose phosphate pathway |
| D-Glucose | [M-H]− | 0.34 | 179.0552 | 179.0561 | 5.0 | 127.0377 | 92.0394 | 85.0281 | Glycolysis/ Gluconeogenesis |
| Hippuric acid | [M-H]− | 1.97 | 178.0501 | 178.051 | 5.1 | 134.0607 | 77.0399 | - | Phenylalanine metabolism |
| Glutaric acid | [M-H]− | 0.79 | 131.0345 | 131.035 | 7.6 | 113.0244 | 87.0458 | 69.0358 | Fatty acid degradation, lysine degradation |
| Taurine | [M-H]− | 0.32 | 124.0069 | 124.0074 | 4.0 | 79.9567 | - | - | Primary bile acid biosynthesis, taurine and hypotaurine metabolism |