Table 1.
MS2 results for ten commonly known metabolites.
| Metabolite | m/z a | ppm b | Formula | Size c | Score d | Rank e |
|---|---|---|---|---|---|---|
| Phenylalanine | 166.0859 | 2 | C9H11NO2 | 1881 | 1.0000 | 1 |
| Valine | 118.0850 | 10 | C5H11NO2 | 453 | 0.9240 | 6 |
| Nicotinate | 124.0392 | 0 | C6H5NO2 | 100 | 0.8900 | 7 |
| Pantothenate | 220.1174 | 2 | C9H17NO5 | 563 | 0.8963 | 8 |
| Glutamine | 147.0746 | 12 | C5H10N2O3 | 283 | 0.8404 | 10 |
| Methionine | 150.0575 | 5 | C5H11NO2S | 212 | 0.8952 | 13 |
| Isoleucine | 132.1016 | 2 | C6H13NO2 | 962 | 0.8723 | 22 |
| Proline | 116.0703 | 2 | C5H9NO2 | 528 | 0.8515 | 26 |
| Thymidine | 243.0971 | 1 | C10H14N2O5 | 948 | 0.9110 | 40 |
| Leucine | 132.1018 | 0 | C6H13NO2 | 962 | 0.7002 | 148 |
a Experimentally detected m/z ratio of [M + H]+; b m/z ratio difference (in units of ppm) between experimentally detected and theoretical m/z ratio of a given ion; c Number of structures for a given molecular formula (obtained with ChemSpider); d Matching score between experimental and predicted MS2 of a given metabolite (obtained with MetFrag), where 1.0 represents the best score. The score goes toward 0 as the agreement between experimental and predicted MS2 decreases; e Rank-ordered agreement between experimental and predicted MS2 of a given metabolite (obtained with MetFrag).