Table 4.
Differential metabolites from fetal livers in the top ten enriched KEGG pathways
| Metabolitea | m/z | rt(s) | VIP | Fold change | P value |
|---|---|---|---|---|---|
| Lysine degradation | |||||
| N6-Acetyl-L-lysine | 189.12 | 653.67 | 1.85 | 1.30 | 0.022 |
| L-Lysine | 147.11 | 984.76 | 4.86 | 1.19 | < 0.000 |
| L-Pipecolic acid | 130.09 | 984.75 | 3.83 | 1.19 | < 0.000 |
| Glutaric acid | 131.04 | 491.25 | 1.39 | 0.49 | 0.046 |
| DL-2-Aminoadipic acid | 162.08 | 697.23 | 1.37 | 1.68 | 0.066 |
| Glycine | 74.03 | 704.95 | 1.19 | 1.30 | 0.002 |
| Glycerophospholipid metabolism | |||||
| Glycerol 3-phosphate | 171.01 | 816.37 | 5.92 | 1.18 | 0.053 |
| Glycerophosphocholine | 258.11 | 763.17 | 1.76 | 0.65 | 0.023 |
| Phosphorylcholine | 242.08 | 732.23 | 4.08 | 0.73 | 0.045 |
| Acetylcholine | 146.12 | 709.06 | 5.58 | 0.82 | 0.040 |
| O-Phosphoethanolamine | 140.01 | 864.35 | 2.45 | 1.12 | 0.082 |
| sn-Glycerol 3-phosphoethanolamine | 216.06 | 740.82 | 7.13 | 0.69 | 0.038 |
| Fructose and mannose metabolism | |||||
| Alpha-D-Glucose | 179.06 | 557.54 | 9.79 | 1.44 | 0.012 |
| D-Sorbitol | 181.07 | 556.12 | 13.69 | 0.72 | 0.014 |
| D-Mannitol | 183.09 | 551.07 | 5.18 | 0.71 | 0.046 |
| D-Mannose | 198.10 | 551.23 | 3.52 | 1.40 | 0.032 |
| Beta-D-Fructose 6-phosphate | 259.02 | 814.70 | 1.60 | 0.77 | 0.018 |
| DL-lactate | 89.03 | 556.73 | 1.15 | 1.24 | 0.088 |
| Galactose metabolism | |||||
| Alpha-D-Glucose | 179.06 | 557.54 | 9.79 | 1.44 | 0.012 |
| D-Sorbitol | 181.07 | 556.12 | 13.69 | 0.72 | 0.014 |
| D-Mannose | 198.10 | 551.23 | 3.52 | 1.40 | 0.032 |
| Glycerol | 151.06 | 187.25 | 1.08 | 1.06 | 0.081 |
| D-Tagatose | 179.06 | 370.37 | 1.15 | 0.65 | 0.061 |
| Arginine biosynthesis | |||||
| L-Glutamine | 145.06 | 699.84 | 5.05 | 1.08 | 0.037 |
| L-Pyroglutamic acid | 130.05 | 559.43 | 2.25 | 1.25 | 0.007 |
| L-Citrulline | 176.10 | 731.72 | 3.45 | 1.42 | 0.007 |
| Purine metabolism | |||||
| L-Glutamine | 145.06 | 699.84 | 5.05 | 1.08 | 0.037 |
| Inosine | 269.09 | 306.89 | 1.26 | 0.41 | 0.031 |
| Hypoxanthine | 135.03 | 304.52 | 5.86 | 1.06 | 0.084 |
| Adenosine | 250.09 | 186.16 | 1.65 | 0.77 | 0.071 |
| Adenosine 5′-diphosphate (ADP) | 426.02 | 870.44 | 1.04 | 1.19 | 0.072 |
| Glycine | 74.03 | 704.95 | 1.19 | 1.30 | 0.002 |
| Primary bile acid biosynthesis | |||||
| Taurochenodeoxycholate | 498.29 | 251.31 | 10.41 | 1.48 | 0.047 |
| Glycine | 74.03 | 704.95 | 1.19 | 1.30 | 0.002 |
| Taurocholate | 516.30 | 381.79 | 1.89 | 0.67 | 0.067 |
| Glycocholic acid | 483.34 | 465.40 | 1.68 | 0.45 | 0.022 |
| Histidine metabolism | |||||
| 1-Methylhistidine | 170.09 | 691.63 | 2.94 | 1.34 | 0.069 |
| L-Carnosine | 227.11 | 791.19 | 3.32 | 0.79 | 0.012 |
| L-Histidine | 156.08 | 706.27 | 3.82 | 1.26 | 0.022 |
| 1-Methylhistamine | 126.10 | 624.34 | 3.19 | 2.84 | 0.033 |
| Glycine, serine and threonine metabolism | |||||
| DL-Serine | 104.04 | 704.80 | 6.00 | 1.29 | 0.001 |
| Glycine | 74.03 | 704.95 | 1.19 | 1.30 | 0.002 |
| L-Threonine | 120.07 | 654.22 | 2.79 | 1.14 | 0.007 |
| Glycolysis/Gluconeogenesis | |||||
| alpha-D-Glucose | 179.06 | 557.54 | 9.79 | 1.44 | 0.012 |
| D-Glucose 6-phosphate | 261.04 | 895.44 | 4.43 | 0.67 | 0.065 |
| DL-lactate | 89.03 | 556.73 | 1.15 | 1.24 | 0.088 |
aDifferential metabolites were identified based on the variable importance for a projection (VIP) value > 1, a correlation coefficient between the X variables and a predictive score of predictive component 1 [p (corr)] > 0.6 in the OPLS-DA model and an independent t-test with a significant difference (P < 0.05) and a potential difference (0.05 < P < 0.10). If one differential metabolite was detected in both positive and negative modes, the parameters from positive mode are presented