TABLE 1.
Muropeptides analyzed by UPLC-MS in positive-ion mode
| Peaka | Retention time (min) |
Calculated mass |
Observed m/z |
Length of the stem peptides |
|---|---|---|---|---|
| 1 | 7.6 | 870.37 | 871.37 (+1) | Tri |
| 2 | 9 | 698.29 | 699.29 (+1) | Di |
| 3 | 12 | 941.41 | 942.41 (+1) | Tetra |
| 4a | 13.7 | 1,722.71 | 575.23 (+3) | Tri-tri |
| 4b | 20.3 | 1,722.71 | 862.35 (+2) | Tri-tri |
| 5a | 21.7 | 1,793.77 | 897.88 (+2) | Tri-tetra |
| 5b | 22.8 | 1,793.77 | 897.88 (+2) | Tri-tetra |
| 6 | 24.1 | 1,864.81 | 933.40 (+2) | Tetra-tetra |
| 7a | 28 | 2,717.15 | 906.71 (+3) | Tri-tetra-tetra |
| 7b | 29.2 | 2,717.15 | 906.71 (+3) | Tri-tetra-tetra |
| 8 | 30.1 | 2,788.21 | 930.40 (+3) | Tetra-tetra-tetra |
| 9a | 30.7 | 1,773.74 | 887.87 (+2) | Anhydro tri-tetra |
| 9b | 31.9 | 1,773.74 | 887.87 (+2) | Anhydro tri-tetra |
| 10 | 33.2 | 1,844.77 | 923.38 (+2) | Anhydro tetra-tetra |
a
Refer to chromatograms in Fig. S4.