Molecular ions [MH+] and main product ions of GS-A1 and GS-A2 detected by high-resolution mass spectrometry
| Determined MH+ | Theoretical MH+ (Elemental Composition) | Mass Error | Characterization | |
|---|---|---|---|---|
| ppm | ||||
| GS-A1 | 437.1486 | 437.1489 (C19H25N4O6S) | −0.69 | Molecular ion |
| MS2 of GS-A1 | 308.0907 | 308.0911 (C10H18N3O6S) | −1.30 | Protonated GSH |
| MS3 of GS-A1 | 233.0586 | 233.0596 (C8H13N2O4S) | −4.29 | Further loss of glycine |
| 179.0485 | 179.0490 (C5H11N2O3S) | −2.79 | Further loss of pyroglutamate | |
| 162.0219 | 162.0225 (C5H8NO3S) | −3.70 | Further loss of pyroglutamate and NH3 | |
| GS-A2 | 437.1486 | 437.1489 (C19H25N4O6S) | −0.69 | Molecular ion |
| MS2 of GS-A2 | 308.1061 | 308.1069 (C14H18N3O3S) | −2.60 | Neutral loss of pyroglutamate |
| MS3 of GS-A2 | 233.0743 | 233.0749 (C12H13N2OS) | −2.57 | Further loss of glycine |