Table 2. Urine potential biomarkers associated with ESCC.
| No. | RT(min) | m/z | metabolite identification | P-valuec | VIPd | trende | related pathway | The identification scoref |
|---|---|---|---|---|---|---|---|---|
| 1 | 9.43 | 130.0501 | Pyroglutamic acidb | 3.65E-06 | 6.59 | ↑ | Glutamine metabolism | 6 |
| 2 | 7.45 | 134.0591 | Indoxylb | 0.006 | 1.52 | ↑ | Tryptophan metabolism | 6 |
| 3 | 2.27 | 139.0507 | Urocanic acida,b | 0.017 | 1.53 | ↑ | Histidine metabolism | 8 |
| 4 | 1.45 | 162.1097 | L-Carnitinea,b | 0.021 | 2.79 | ↑ | Fatty acid transportation | 8 |
| 5 | 2.27 | 165.0554 | L-Fucosea,b | 0.003 | 1.88 | ↑ | Fructose and mannose degradation | 8 |
| 6 | 2.89 | 169.0378 | Uric acida,b | 4.89E-05 | 7.12 | ↑ | Purine metabolism | 8 |
| 7 | 9.56 | 181.0719 | Paraxanthineb | 0.012 | 2.31 | ↓ | Caffeine metabolism | 6 |
| 8 | 2.07 | 204.1249 | Acetylcarnitineb | 0.025 | 6.65 | ↑ | Fatty acid β oxidation | 6 |
| 9 | 3.41 | 228.0801 | Deoxycytidinea,b | 2.51E-09 | 4.36 | ↑ | Pyrimidine metabolism | 8 |
| 10 | 9.43 | 265.1169 | Phenylacetylglutaminea,b | 7.8E-07 | 12.91 | ↑ | Phenylalanine metabolism | 8 |
| 11 | 11.93 | 274.2009 | Heptanoylcarnitine (carnitine C 7:0)b | 0.031 | 1.69 | ↓ | Fatty acid β oxidation | 6 |
| 12 | 12.3 | 286.2005 | Octenoylcarnitine (carnitine C 8:1) | 0.008 | 2.13 | ↓ | Fatty acid β oxidation | 4 |
| 13 | 13.39 | 300.2163 | Nonenoylcarnitine (carnitine C 9:1) | 0.025 | 1.39 | ↓ | Fatty acid β oxidation | 4 |
| 14 | 14.03 | 302.2319 | Nonanoylcarnitine (carnitine C 9:0)b | 0.0025 | 3.39 | ↓ | Fatty acid β oxidation | 6 |
| 15 | 14.92 | 316.2472 | Decanoylcarnitine (carnitine C 10:0)a,b | 0.012 | 1.36 | ↓ | Fatty acid β oxidation | 8 |
| 16 | 15.14 | 328.2473 | Undecenoylcarnitine (carnitine C 11:1) | 0.019 | 1.78 | ↓ | Fatty acid β oxidation | 4 |
| 17 | 5.08 | 330.0588 | cAMPa,b | 0.016 | 2.15 | ↑ | Purine metabolism | 8 |
| 18 | 11.70 | 330.2650 | Undecanoylcarnitine (carnitine C 11:0)b | 0.019 | 1.45 | ↓ | Fatty acid β oxidation | 6 |
| 19 | 4.94 | 346.0547 | cGMPa,b | 2E-14 | 3.17 | ↑ | Purine metabolism | 8 |
aMetabolites confirmed by standard compounds. bMetabolites provisionally identified by database searches and MS fragmentation. Others, proposals based on MS fragmentation and exact mass data. cP value of independent t-test. dVIP is variable importance in the projection obtained from OPLS-DA with a threshold of 1.0. eChange trend compared with controls. (↑): up-regulated. (↓): down-regulated. fThe identification score is calculated by the scoring metric.