Table 1.
Tentative identification and quantification of phenolic compounds in B. alba and B. rubra stem extracts by HPLC–ESI–MS method
| Tentative compound identity | Plant species | Molecular formula | Retention time (min) | [M+H]+ | [M–H]− | Total content (μg/g) |
|---|---|---|---|---|---|---|
| 4-hydroxy benzaldehyde | B. rubra | C7H6O2 | 2.51 | – | 121.1 | 9.35 ± 0.13 |
| Gallic acid | B. alba | C7H6O5 | 3.43 | – | 169.10 | 15.12 ± 0.07 |
| p-Coumaric acid | B. rubra | C9H803 | 3.85 | – | 163.0 | 59.65 ± 1.49 |
| Salicylic acid | B. alba | C7H6O3 | 4.36 | – | 137.02 | 16.16 ± 0.49 |
| Caffeic acid | B. rubra | C9H8O4 | 2.55 | – | 179.2 | 40.44 ± 1.04 |
| Ferulic acid | B. alba | C10H10O4 | 10.00 | 195.97 | – | 20.25 ± 0.40 |
| Trans-cinnamic acid | B. rubra | C9H8O2 | 9.25 | 149.3 | – | 15.08 ± 0.11 |
| Galloyl shikimic acid | B. rubra | – | 11.03 | – | 325.1 | 5.77 ± 0.34 |
| Diosmetin | B. rubra | C16H12O6 | 10.86 | 301.4 | – | 13.61 ± 0.18 |