Table 1.
UPLC Q-TOF-MS analysis of polyphenolic components in QPE.
| No. | Compound | RT (min) | [M−H]− (m/z) | Fragment Ions (m/z) |
|---|---|---|---|---|
| 1 | Vanillic acid | 4.50 | 167.0391 | 152.0116, 108.0229 |
| 2 | Protocatechuic acid | 4.53 | 153.0188 | 109.0297, 108.0218 |
| 3 | Caffeic acid | 5.48 | 179.0422 | 135.0458 |
| 4 | p-Hydroxybenzoic acid | 6.07 | 137.0302 | 93.0341 |
| 5 | p-Coumaric acid | 6.78 | 163.0401 | 119.0509 |
| 6 | Ferulic acid | 7.60 | 193.0555 | 178.0267, 149.0601, 134.0368 |
| 7 | (-)-Catechin | 8.06 | 289.0862 | 175.0351, 137.0212, 134.0440, 123.0479 |
| 8 | (-)-Epicatechin | 8.07 | 289.0862 | 137.0243, 123.0448, 109.0295 |
| 9 | Sinapic acid | 8.15 | 223.0689 | 194.0116, 165.0168, 147.0482 |