Table 2.
Differential metabolites in positive and negative ionization mode. References indicate BC’s previous clinical studies in which the metabolite was selected as discriminant and/or dysregulated (MW—molecular weight; ↓ indicates down-regulation and ↑ indicates up-regulation in BC).
| Metabolites | MW | RT | VIP Score | Trend |
|---|---|---|---|---|
| Positive ionization mode | ||||
| 2-Acetyl-1-alkyl-sn-glycero-3-phosphocholine [12] | 523.3638 | 17.98 | 1.66212 | ↑ |
| 3-Dehydroxycarnitine | 145.1103 | 3.51 | 1.13186 | ↓ |
| 3-Methylxanthine [13] | 166.0491 | 1.38 | 1.80968 | ↓ |
| 4-Hydroxycinnamic acid | 164.0475 | 4.17 | 1.80279 | ↓ |
| 5-Hydroxyindoleacetic acid [13] | 191.0582 | 8.42 | 1.17858 | ↓ |
| Adenine | 135.0545 | 3.08 | 2.03098 | ↑ |
| Benzoic acid [14] | 122.0370 | 4.17 | 1.38913 | ↓ |
| Carnosine | 226.1064 | 3.95 | 1.06014 | ↓ |
| Epinephrine | 183.0896 | 8.35 | 1.52508 | ↓ |
| Hippuric acid [13,14,15] | 179.0582 | 7.83 | 2.37849 | ↓ |
| Histidine | 155.0695 | 2.14 | 1.30363 | ↓ |
| Isoniazid | 137.0589 | 7.97 | 1.43638 | ↓ |
| LysoPE(18:1) | 479.3014 | 17.55 | 1.66856 | ↑ |
| N-Acetyl-phenylalanine | 207.0896 | 9.17 | 1.73877 | ↓ |
| p-Aminobenzoic acid [13] | 137.0477 | 1.44 | 1.45154 | ↓ |
| Retinol | 286.2295 | 12.93 | 1.07027 | ↓ |
| Theophylline | 180.0648 | 6.76 | 2.21588 | ↓ |
| Negative ionization mode | ||||
| 3-(3-sulfooxyphenyl)propanoic acid | 246.0195 | 7.18 | 1.72228 | ↓ |
| Adenosine monophosphate * | 347.0631 | 1.18 | 1.60799 | ↑ |
| Gluconic acid [16,17] | 196.0587 | 1.39 | 1.74004 | ↓ |
| Hippuric acid [13,14,15] | 179.0583 | 7.81 | 2.21443 | ↓ |
| Indolelactic acid [13] | 205.0739 | 11.00 | 1.31510 | ↓ |
* Fragmentation spectrum not confirmed with online databases.