TABLE 1
Mass spectrometric data for GDC-0425 and its metabolites with proposed structural elucidation
Glucuronide conjugates were observed with [M+H]+ at 176 Da mass shift higher than their corresponding aglycones. Other than M17, for which the corresponding aglycone was not detected, the conjugates have not been listed but were assigned unique metabolite identifiers.
| Analyte | Observed MH+ (Chemical Formula, Mass Accuracy in ppm) | Characteristic Product Ions (m/z) Ions at m/z 98, 84, and 70 for GDC-0425 can also be rationalized as cleavages at N-ethyl of 1-ethylpiperidine. | Structure and MS/MS Product Ions |
|---|---|---|---|
| GDC-0425 | 322.1665 (C18H20N5O+, 0.9) | 112 (100), 98, 84, 70, 58 |  |
| M1 | 57.9769 (negative ion) (-SCN, 21) | N/A | Thiocyanate |
| M5 | 211.0614 (C11H7N4O+, 0) | 193, 184 (100), 156 |  |
| M7 | 310.1299 (C16H16N5O2+, 0) | 293, 227 (100), 84, 56 |  |
| M9 | 338.1611 (C18H20N5O2+, -0.3) | 320, 254, 227, 112 (100), 98, 84, 70, 58 |  |
| M10 | 294.1348 (C16H16N5O+, -0.3) | 211, 84 (100), 56 |  |
| M14 | 338.1611 (C18H20N5O2+, -0.3) | 320, 306 (100), 278, 251, 128, 112, 110, 74 |  |
| M16 | 336.1454 (C18H18N5O2+, -0.3) | 294, 253, 211 (100), 126, 84, 56 |  |
| M17 | 505.1928 (C23H29N4O9+, -0.2) | 329 (100), 254, 112, 98, 84 |  |
| M18 | 313.1657 (C17H21N4O2+, -0.5) | 268, 202, 112 (100) |  |
HCN, hydrogen cyanide; MH+, protonated molecular ion; N/A, not assessed; SCN−, thiocyanate.