Table 1.
Benzoxazinoids and phenolic compounds were identified in the extracts by HPLC–PDA–ESI/MSn.
| No. | λmáx (nm) | [M-H]- | HPLC–ESI/MSn m/z |
Tentative Identification | Compounds Detected | ||
|---|---|---|---|---|---|---|---|
| EEt | EI | ED | |||||
| 1 | 256, 264 sh, 280, 287 sh | - | - | DIBOA * | ✓ | ✓ | ✓ |
| 2 | 255, 277, 284 sh | - | - | HBOA * | ✓ | ✓ | ✓ |
| 3 | 261, 283 sh, 321 sh, 329 | 387 | MS2: 163; 207; 369 MS3: 163 |
Medioresinol | ✓ | ✗ | ✗ |
| 4 | 271, 277 sh | - | - | BOA | ✓ | ✓ | ✓ |
| 5 | 256, 287 sh, 300 sh, 330 | 639 | MS2: 529; 621 MS3: 459; 469 |
β-OH-verbascoside | ✓ | ✓ | ✓ |
| 6 | 256, 285 sh, 300 sh, 331 | 639 | MS2: 529; 621 MS3: 459; 469 |
β-OH-verbascoside | ✓ | ✓ | ✓ |
| 7 | 267, 336 | 621 | MS2: 351 MS3: 113; 175; 193; 289; 333 |
Apigenin di-glucuronide | ✗ | ✓ | ✓ |
| 8 | 258, 288 sh, 291, 299 sh, 331 | 623 | MS2: 461 MS3: 315 |
Verbascoside * | ✓ | ✓ | ✓ |
| 9 | 260, 268 sh, 287 sh, 342 | 637 | MS2: 285; 351 MS3: 113; 175; 193; 289; 333 |
Luteolin di-glucuronide | ✗ | ✓ | ✓ |
| 10 | 248, 288 sh, 300 sh, 331 | 667 | MS2: 621 MS3: 179; 459 |
β-EtOH-verbascoside isomer | ✓ | ✗ | ✗ |
| 11 | 247, 289 sh, 300 sh, 330 | 667 | MS2: 621 MS3: 179; 459; 469 |
β-EtOH-verbascoside isomer | ✓ | ✗ | ✗ |
| 12 | 267, 289 sh, 342 | 651 | MS2: 351; 517 MS3: 113; 175; 193; 289; 333 |
Hispidulin di-glucuronide | ✗ | ✗ | ✓ |
| 13 | 261, 286, 299, 331 | 623 | MS2: 461 MS3: 135; 161; 297; 315 |
Verbascoside isomer | ✓ | ✗ | ✗ |
| 14 | 272, 334 | 475 | MS2: 299; 175 MS3: 284 |
Hispidulin glucuronide | ✓ | ✓ | ✓ |
According to the authors, identification was based on the UV–Vis spectra, molecular weight, and fragmentation patterns [16,17,18,19,20,21,22,23]. EI—infusion; ED—decoction; EEt—ethanol extract; sh—shoulder; bold—base peaks in MS spectra; * identification confirmed by comparison with authentic standards; DIBOA (2,4-dihydroxy-1,4-benzoxazin-3-one); HBOA (2-hydroxy-1,4-benzoxazin-3-one); BOA (benzoxazoline-2-on.e).