Table 2.
Identification of phenolic acids and their derivatives in Fr. 1.
| Peak a | Compound b | tR (min) | Formula | [M − H]− (m/z) | Fragment Ion (m/z) | ||
|---|---|---|---|---|---|---|---|
| Measured | Calculated | Error (ppm) | |||||
| Hydroxybenzoic acids and their derivatives | |||||||
| A1 | Gallic acid | 3.07 | C7H6O5 | 169.0141 | 169.0142 | −0.86 | 125.0244 |
| A2 | Protocatechuic acid | 5.70 | C7H6O4 | 153.0190 | 153.0193 | −2.15 | 109.0129 |
| A3 | p-Hydroxybenzoic acid | 9.08 | C7H6O3 | 137.0243 | 137.0244 | −0.59 | 93.0340, 65.0394 |
| A4 | Vanillic acid | 11.82 | C8H8O4 | 167.0346 | 167.0350 | −2.31 | 123.0450 |
| A5 | p-Hydroxybenzaldehyde | 12.00 | C7H6O2 | 121.0291 | 121.0295 | −3.51 | - |
| A6 | Syringic acid | 13.76 | C9H10O5 | 197.0447 | 197.0455 | −3.94 | 153.0551, 123.0449 |
| A7 | Vanillin | 15.19 | C8H8O3 | 151.0398 | 151.0401 | −1.83 | 136.0163, 107.0500 |
| A12 | Protocatechuic acid ethyl ester | 26.25 | C9H10O4 | 181.0504 | 181.0506 | −0.98 | 153.0553 |
| Hydroxycinnamic acids | |||||||
| A8 | p-Coumaric acid | 19.93 | C9H8O3 | 163.0397 | 163.0401 | −2.39 | 119.0500 |
| A9 | o-Coumaric acid | 20.82 | C9H8O3 | 163.0396 | 163.0401 | −2.87 | 119.0500 |
| A10 | Ferulic acid | 23.91 | C10H10O4 | 193.0503 | 193.0506 | −2.05 | 149.0602 |
| A11 | Sinapic acid | 25.11 | C11H12O5 | 223.0603 | 223.0612 | −4.08 | 179.0709, 164.0471 |
a Peaks were numbered according to their order of elution from the lowest to the highest retention times. b Identification of the compounds was confirmed by authentic standards. tR, retention time.