Table 2. Marker metabolites found in OPLS-DA models of 1H NMR-based urine metabolic profiling between stage I/II CRC patients and EC patients.
| Metabolites | Chemical shift (ppm) | I/II stage of CRC vs EC | Related metabolomic pathway | ||
|---|---|---|---|---|---|
| VIPa | p-valueb | Variations vs EC | |||
| Thymidine | 6.28(t) 7.63(s) |
1.82 1.36 |
0.000 0.033 |
↑ ↑ |
Nucleotide metabolism |
| Fumarate | 6.51(s) | 1.71 | 0.000 | ↑ | TCA cycle, Arginine and Proline metabolism, Aspartate metabolism |
| Hippurate | 7.54(m) 7.62(tt) |
1.47 1.52 |
0.036 0.019 |
↑ ↑ |
Gut microflora metabolism |
| cis-Aconitate | 6.58(s) | 1.69 | 0.000 | ↑ | TCA cycle, Glyoxylate, Dicarboxylate metabolism |
| Pyridoxic acid | 7.53(s) 4.51(s) |
1.62 1.50 |
0.003 0.000 |
↑ ↑ |
Vitamin B6 metabolism |
| Cinnamic acid | 6.51(d) 7.39(d) 7.44(m) 7.61(dd) |
1.71 1.31 1.62 1.53 |
0.000 0.022 0.001 0.019 |
↑ ↑ ↑ ↑ |
unknown |
| Homogentisic acid | 6.71(m) | 1.23 | 0.000 | ↑ | Phenylalanine and tyrosine metabolism, Disulfiram pathway |
| Indoleacetate | 7.24(m) 7.50(d) 7.62(d) |
1.23 1.47 1.18 |
0.002 0.009 0.004 |
↑ ↑ |
Amino acid metabolism, Tryptophan metabolism |
| Trigonelline | 8.83(m) | 1.42 | 0.043 | ↑ | Vitamin metabolism |
| Creatinine | 3.03(s) 4.05(s) |
1.67 1.25 |
0.000 0.008 |
↓ ↓ |
Urea metabolism, Creatinine metabolism |
| Creatine | 3.02(s) | 1.67 | 0.000 | ↓ | Urea metabolism, Creatine metabolism |
| Uracil | 5.79(d) | 1.47 | 0.003 | ↓ | Pyrimidine metabolism |
| Urea | 5.78(br, s) | 1.41 | 0.003 | ↓ | Urea metabolism |
a: Variable importance in the projection (VIP) was obtained from OPLS-DA with a threshold of 1.0.
b: p value was calculated from Mann-Whitney U test.