Table 1. ESI mass spectra of compounds 1–6 [m/z (relative abundance, %)].
| 1 | 2 | 3 | 4 | 5 | 6 | |
|---|---|---|---|---|---|---|
| [M+H]+ | 358 (100) | 419 (100) | 434 (76) | 495 (46) | 463 (100) | 507 (100) |
| [M+18]+ | 375 (58) | 436 (63) | — | 512 (31) | — | 525 (7) |
| [M+Na]+ | 380 (43) | 441 (79) | 456 (82) | 517 (19) | 485 (43) | 529 (43) |
| [M+K]+ | 396 (18) | 457 (23) | 472 (11) | 533 (10) | 501 (19) | 545 (36) |
| [C9H7O3]+ | 163 (26) | 163 (27) | — | 163 (38) | — | — |
| [C7H5O2]+ | 121 (36) | 121 (68) | 121 (100) | 121 (100) | — | — |