Table 2.
Average content of polyphenols and respective retention time (Rt) and wavelengths of maximum absorption in the visible region (λ max) in P. tridentatum extracts (by elution order)†.
| Polyphenols | Rt (min) | UV (nm) | UV-DAD/VIS bands (nm) in 70% methanol |
Class | Mg·g−1 dry weight |
|---|---|---|---|---|---|
| Taxifolin | 17.48 | 280 | 290, 327sh | Flavanol | 21.76 ± 0.030 |
| Genistin | 19.79 | 320 | 259, 323sh | Isoflavone | 16.75 ± 0.040 |
| Genistein | 22.73 | 320 | 259, 332sh | Isoflavone | 12.01 ± 0.030 |
| Quercetin-3-O-rutinoside | 23.88 | 370 | 256, 266sh, 351 | Flavonol | 1.58 ± 0.030 |
| Quercetin-3-O-glucoside | 23.99 | 370 | 255, 266sh, 348 | Flavonol | 1.23 ± 0.010 |
| Ferulic acid | 24.32 | 320 | 244, 296sh, 324 | Hydroxycinnamic acid | 0.27 ± 0.002 |
| Biochanin A-glucoside | 30.66 | 320 | 265, 322sh | Flavone | 1.37 ± 0.002 |
| Apigenin | 32.65 | 370 | 229, 267sh, 341 | Flavone | 0.44 ± 0.002 |
| Biochanin A | 34.88 | 320 | 265, 323sh | Flavone | 2.89 ± 0.004 |
|
| |||||
| Total of hydroxycinnamic acids | 0.27 ± 0.002 | ||||
| Total of flavonols | 24.57 ± 0.100 | ||||
| Total of flavone | 4.70 ± 0.008 | ||||
| Total of isoflavone | 28.76 ± 0.070 | ||||
| Total of polyphenols identified | 58.30 ± 0.180 | ||||
†Values expressed as mean ± standard deviation of three replicates.