Table 1.
Assigned flavan-3-ol species in peanut testa.
| Precursor Ion [M − H]−, (m/z) | Flavan-3-ol Species | Number of Linkage | Fragment Ions for Assignment [M − H]−, (m/z) |
|||
|---|---|---|---|---|---|---|
| A-Type | B-Type | |||||
| 289.1 | Catechin and/or epicatechin | 245, 125 | ||||
| QM | RDA | HRF | ||||
| 575.1 | A-type procyanidin dimers | 1 | 0 | 289, 285 | 407 | 449 |
| 577.1 | B-type procyanidin dimers | 0 | 1 | 289, 287 | 425, 407 | 451 |
| 861.2 | A-type procyanidin trimers | 2 | 0 | 575, 289, 285 | 693, 407 | 735, 449 |
| 863.2 | A-type procyanidin trimers | 1 | 1 | 575, 573, 289, 287, 285 | 711, 695, 693, 407 | 737, 451, 449 |
| 1149.3 | A-type procyanidin tetramers | 2 | 1 | 863, 861, 575, 573, 289, 287, 285 | 997, 981, 979, 711, 695, 693, 425, 407 | 1023, 737, 735, 451, 449 |
| 1151.3 | A-type procyanidin tetramers | 1 | 2 | 863, 861, 575, 573, 289, 287, 285 | 999, 981, 711, 695, 693, 425, 407 | 1025, 739, 737, 451, 449 |
Matrix-assisted laser desorption/ionization-tandem mass spectrometry (MALDI-MS/MS) spectra were obtained from the outer epidermis of the testa in peanut sections after MALDI-MS imaging analysis, using an ultrafleXtreme instrument operated in collision-induced dissociation “LIFT” MS/MS mode. Fragment ions obtained by quinone methide (QM), retro-Diels-Alder (RDA), and heterocyclic ring fission (HRF) reactions were used for molecular assignments [2,26].