Table 2.
Probability of different numbers of protonation sites, estimated number of protonation sites and literature number of protonation sites for 51 resonances from 32 metabolites in human urine
| Metabolite | Database ID | Chemical shift at pH7.4 | 1 Site prob. | 2 Site prob. | 3 Site prob. | Estimated number of sites | Literature number of sites |
|---|---|---|---|---|---|---|---|
| Hydroxyisobutyrate | HMDB0000729 | 1.347 | 91.893 | 7.488 | 0.619 | 1 | 1 |
| Hydroxyisovalerate | HMDB0000754 | 1.260 | 86.597 | 12.795 | 0.608 | 1 | 1 |
| Indoxyl | HMDB0004094 | 7.192 | 93.017 | 5.688 | 1.295 | 1 | 1 |
| Methyl-2-oxovalerate | HMDB0000695 | 1.093 | 95.383 | 4.326 | 0.291 | 1 | 1 |
| Acetate | HMDB0000042 | 1.910 | 93.326 | 5.879 | 0.795 | 1 | 1 |
| Alanine | HMDB0000161 | 1.212 | 0 | 80.827 | 19.173 | 2 | 2 |
| Allantoin | HMDB0000462 | 5.383 | 97.868 | 2.049 | 0.083 | 1 | 1 |
| Citrate | HMDB0000094 | 2.528 | 0 | 75.404 | 24.596 | 2 | 3 |
| Citrate | HMDB0000094 | 2.646 | 0 | 47.869 | 52.131 | 3 | 3 |
| Creatinine | HMDB0000562 | 3.033 | 87.889 | 11.593 | 0.518 | 1 | 2 |
| Creatinine | HMDB0000562 | 4.043 | 94.992 | 4.65 | 0.358 | 1 | 2 |
| Formate | HMDB0000142 | 8.448 | 92.786 | 6.377 | 0.837 | 1 | 1 |
| Glucose | HMDB0000122 | 5.228 | 98.661 | 1.284 | 0.055 | 1 | 1 |
| Hippurate | HMDB0000714 | 3.960 | 70.111 | 27.403 | 2.486 | 1 | 1 |
| Hippurate | HMDB0000714 | 7.541 | 86.036 | 9.798 | 4.166 | 1 | 1 |
| Hippurate | HMDB0000714 | 7.627 | 92.742 | 6.114 | 1.144 | 1 | 1 |
| Hippurate | HMDB0000714 | 7.824 | 92.264 | 5.387 | 2.349 | 1 | 1 |
| Hippurate | HMDB0000714 | 8.512 | 54.082 | 26.841 | 19.077 | 1 | 1 |
| Histidine | HMDB0000177 | 7.253 | 0 | 42.669 | 57.331 | 3 | 3 |
| Histidine | HMDB0000177 | 8.188 | 0 | 7.55 | 92.45 | 3 | 3 |
| Imidazole | HMDB0001525 | 7.229 | 59.201 | 37.952 | 2.847 | 1 | 1 |
| Imidazole | HMDB0001525 | 8.040 | 0 | 73.582 | 26.418 | 2 | 1 |
| Isoleucine | HMDB0000172 | 0.902 | 0.801 | 65.964 | 33.235 | 2 | 2 |
| Lactate | HMDB0000190 | 1.320 | 89.155 | 9.941 | 0.904 | 1 | 1 |
| Leucine | HMDB0000687 | 0.932 | 83.263 | 14.099 | 2.638 | 1 | 2 |
| Mannitol | HMDB0000765 | 3.673 | 92.487 | 6.501 | 1.012 | 1 | 1 |
| Mannitol | HMDB0000765 | 3.797 | 96.633 | 2.676 | 0.691 | 1 | 1 |
| Mannitol | HMDB0000765 | 3.864 | 96.567 | 2.964 | 0.469 | 1 | 1 |
| Methylsuccinate | HMDB0001844 | 1.062 | 43.561 | 50.274 | 6.165 | 2 | 2 |
| Piperazine | HMDB0014730 | 3.526 | 0 | 65.255 | 34.745 | 2 | 2 |
| TMethylHistidine | HMDB0000479 | 6.873 | 0 | 14.792 | 85.208 | 3 | 3 |
| TMethylHistidine | HMDB0000479 | 8.306 | 0 | 0 | 100 | 3 | 3 |
| TTMethylHistidine | HMDB0000001 | 3.788 | 0 | 94.773 | 5.227 | 2 | 3 |
| TTMethylHistidine | HMDB0000001 | 6.909 | 0 | 16.988 | 83.012 | 3 | 3 |
| TTMethylHistidine | HMDB0000001 | 8.396 | 0 | 23.514 | 76.486 | 3 | 3 |
| Tartrate | HMDB0029878 | 4.322 | 5.764 | 51.864 | 42.372 | 2 | 2 |
| Taurine | HMDB0000251 | 3.412 | 86.863 | 7.137 | 6 | 1 | 2 |
| Threonine | HMDB0000167 | 1.194 | 14.472 | 67.882 | 17.646 | 2 | 2 |
| Trigonelline | HMDB0000875 | 4.429 | 68.693 | 19.481 | 11.826 | 1 | 1 |
| Trigonelline | HMDB0000875 | 8.073 | 74.875 | 17.025 | 8.1 | 1 | 1 |
| Trigonelline | HMDB0000875 | 8.822 | 77.588 | 15.531 | 6.881 | 1 | 1 |
| Trigonelline | HMDB0000875 | 8.834 | 58.857 | 30.807 | 10.336 | 1 | 1 |
| Trigonelline | HMDB0000875 | 9.115 | 67.411 | 21.353 | 11.236 | 1 | 1 |
| Tris | CHEBI:9754 | 3.715 | 94.453 | 5.363 | 0.184 | 1 | 1 |
| Tryptophan | HMDB0000929 | 7.719 | 87.38 | 11.156 | 1.464 | 1 | 2 |
| Tyrosine | HMDB0000158 | 6.885 | 0 | 90.202 | 9.798 | 2 | 3 |
| Tyrosine | HMDB0000158 | 7.207 | 0 | 90.592 | 9.408 | 2 | 3 |
| Valine | HMDB0000883 | 0.906 | 0 | 79.851 | 20.149 | 2 | 2 |
| Valine | HMDB0000883 | 1.060 | 2.967 | 77.568 | 19.465 | 2 | 2 |
| Xylose | HMDB0000098 | 5.190 | 98.475 | 1.476 | 0.049 | 1 | 1 |
| Trans-aconitate | HMDB0000958 | 6.574 | 0 | 64.477 | 35.523 | 2 | 2 |
Rows with correctly estimated numbers of sites are shown in bold