Table 1.
Metabolites that showed statistical significance when comparing PD subjects and healthy controls.
| Metabolite | Mass | RT (min) | RMT | Technique | Error (ppm) | Adduct | CV (% in QC) | % change | p-value | VIP |
|---|---|---|---|---|---|---|---|---|---|---|
| Benzene and substituted derivatives | ||||||||||
| 2-Aminobenzoic acid | 137.0476 | 15.47 | 0.90 | CE–MS | 8 | [M+H]+ | 2.7 | −40.1 | 0.012 | – |
| Carboxylic acids and derivatives | ||||||||||
| Cis-aconitic acid | 174.0164 | 15.72 | – | GC–MS | – | – | 12.5 | −23.1 | 0.056 | – |
| 3-Methoxytyrosine | 211.0844 | 29.85 | 1.73 | CE–MS | 1 | [M+H]+ | 4.3 | 16.0 | 0.026 | – |
| Pipecolic acid | 129.0789 | 15.15 | 0.88 | CE–MS | 6 | [M+H]+ | 4.3 | −52.1 | 0.024 | – |
| Fatty acyls | ||||||||||
| 2-Hydroxy-3-methylbutyric acid | 118.0629 | 8.30 | – | GC–MS | – | – | 4.5 | −29.5 | 0.037 | – |
| CMPF | 240.0998 | 7.08 | – | LC–MS ESI (±) | 1 | [M−H]− | 3.6 | 31.7 | 0.035 | – |
| Arachidonic acid | 304.2402 | 31.02 | – | LC–MS ESI (−) | 8 | [M+FA−H]− | 4.1 | −16.1 | 0.049 | – |
| Docosapentaenoic acid (DPA) | 330.2555 | 28.29 | – | LC–MS ESI (−) | 1 | [M–H]− | 4.2 | −20.3 | 0.041 | – |
| Linoleic acid | 280.2402 | 20.38 | – | GC–MS/LC–MS ESI (−) | – | – | 5.4 | −29.5 | 0.035 | – |
| Oleic acid | 282.2558 | 20.40 | – | GC–MS/LC–MS ESI (−) | – | – | 5.5 | −28.9 | 0.039 | – |
| Palmitic acid | 256.2402 | 18.85 | – | GC–MS/LC–MS ESI (−) | – | – | 4.6 | −20.7 | 0.016 | – |
| Palmitoleic acid | 254.2245 | 18.67 | – | GC–MS/LC–MS ESI (−) | – | – | 5.3 | −33.9 | 0.017 | – |
| Palmitoleoyl-EA | 297.2667 | 21.15 | – | LC–MS ESI (+) | 1 | [M+H]+ | 10.3 | 29.7 | 0.10 | 1.1 |
| Stearic acid | 284.2715 | 20.68 | – | GC–MS/LC–MS ESI (−) | – | – | 10.3 | −17.4 | 0.0056 | – |
| Glycerolipids | ||||||||||
| MG(18:2) | 354.2770 | 25.65 | – | LC–MS ESI (+) | 7 | [M+H]+ | 23.3 | 36.1 | 0.024 | 1.4 |
| Glycerophospholipids | ||||||||||
| LPC(16:1) | 493.3168 | 17.38 | – | LC–MS ESI (+) | 1 | [M+H]+ | 9.3 | 21.1 | 0.054 | 1.2 |
| LPC(17:1) | 507.3316 | 18.22 | – | LC–MS ESI (+) | 2 | [M+H]+ | 6.4 | 16.4 | 0.086 | 1.2 |
| LPC(P-18:0) | 507.3689 | 21.05 | – | LC–MS ESI (+) | 1 | [M+H]+ | 4.2 | 14.6 | 0.10 | 1.2 |
| LPC(22:6) | 613.3371 | 17.71 | – | LC–MS ESI (−) | 1 | [M+FA–H]− | 4.1 | 15.8 | 0.049 | – |
| PC(28:2) | 709.4338 | 31.03 | – | LC–MS ESI (−) | 16 | [M+Cl]− | 6.6 | −32.5 | 0.033 | – |
| PC(36:5) | 779.5465 | 31.18 | – | LC–MS ESI (+) | 1 | [M+H]+ | 23.8 | −31.2 | 0.014 | 1.2 |
| Hydroxy acids and derivatives | ||||||||||
| β-Hydroxybutyric acid | 104.0473 | 8.25 | – | GC–MS | – | – | 5.3 | −51.3 | 0.0079 | – |
| Indoles and derivatives | ||||||||||
| Serotonin | 176.0949 | 13.21 | 0.76 | CE–MS | 2 | [M+H]+ | 5.9 | −43.9 | 0.15 | – |
| Monocarboxylic acid amide | ||||||||||
| Lactamide | 89.0477 | 8.24 | – | GC–MS | – | – | 5.5 | −29.1 | 0.0079 | – |
| Organooxygen compounds | ||||||||||
| Threitol | 122.0579 | 12.89 | – | GC–MS | – | – | 5.4 | −17.2 | 0.040 | – |
| Pyrimidine nucleotides | ||||||||||
| dUMP | 308.0409 | 29.84 | 1.73 | CE–MS | 7 | [M+H]+ | 12.7 | 31.6 | 0.051 | – |
| Sphingolipids | ||||||||||
| 3-Ketosphingosine | 297.2667 | 20.61 | – | LC–MS ESI (+) | 1 | [M+H]+ | 17.5 | 35.2 | 0.063 | 1.2 |
| PE-Cer(d30:2) | 602.4423 | 30.54 | – | LC–MS ESI (−) | 10 | [M−H]− | 7.2 | −22.7 | 0.042 | – |
| Steroids and steroid derivatives | ||||||||||
| Tetrahydroaldosterone-3- glucuronide | 540.2570 | 1.08 | – | LC–MS ESI (−) | 3 | [M−H]− | 5.1 | 20.3 | 0.042 | – |
| Multiple candidates | ||||||||||
| Bile acid 1 | 374.2825 | 14.78 | – | LC–MS ESI (+) | 1 | [M+H−H2O]+ | 9.7 | 57.6 | 0.032 | 1.3 |
| Bile acid 2 | 396.2884 | 22.36 | – | LC–MS ESI (+) | 2 | [M−H]− | 11.6 | 219.1 | 0.041 | 1.0 |
| Vitamine D2/5-Dehydroepisterol | 379.3289 | 23.95 | – | LC–MS ESI (+) | 18 | [M+H−H2O]+ | 5 | 15.4 | 1.62 × 10−7 | 2.7 |
| Vitamine D3 metabolite | 446.3387 | 30.48 | – | LC–MS ESI (−) | 1 | [M−H]− | 14.4 | 52.2 | 0.0063 | – |
| Unknowns | ||||||||||
| Unknown 1 | 445.1517 | 27.06 | – | LC–MS ESI (−) | – | – | 4.7 | −26.3 | 0.026 | – |
| Unknown 2 | 554.2056 | 31.03 | – | LC–MS ESI (−) | – | – | 8.3 | −25.6 | 0.047 | – |
| Unknown 3 | 563.4327 | 31.27 | – | LC–MS ESI (+) | – | – | 10.7 | 27.1 | 0.037 | 1.4 |
RT retention time expressed in minutes, relative MT (RMT) relative migration time based on the migration time of the internal standard added to each sample, CV coefficient of variation calculated in the QCs (30%), % change percentage of change calculated between pre-PD and controls, the sign (−) indicates that this metabolite is less abundant in pre-PD than in controls and the sign (+) indicates that this metabolite is more abundant in pre-PD than in the controls, p-value obtained with the t‐test after FDR correction, VIP variable of importance in projection.
Italic p-values are closed to be statistically significant.