Table 2.
Total phenol content and antioxidant capacity by the DPPH and ORAC assays of crude extract, phases of partition, and flavonoids isolated from P. townsendii.
| Sample Ethanol extract |
Phenol contenta,b (mg of GAE/g)b |
DPPH assay, SC50a,c (µg/mL)c |
ORAC assaya,d (µmol of TE/g)d |
|---|---|---|---|
| Hexane crude extract | < 1.13 | > 200 | 13.0 (5.0) |
| Ethanol crude extract | 3.3 (6.3) | 62.6 (10.0) | 1555 (10.5) |
| Hexane phase | 1.0 (3.5) | > 200 | 2461 (9.7) |
| Dichloromethane phase | 2.5 (7.9) | 45.6 (6.3) | 5641 (4.9) |
| Hydroalcoholic phase | 2.0 (2.8) | 31.9 (7.7) | 4581 (7.7) |
|
| |||
| Patuletin 3-O-β-D-glucopyranoside | - | 4.9 (2.1) | 4.2 (6.9)e |
|
| |||
| Tiliroside | - | 83.2 (3.2) | 0.8 (3.4)e |
|
| |||
| Mixture of patuletin 3-O-β-D-glucopyranoside + Tiliroside | 3.7 (2.5) | 4.8 (11.4)e | |
|
| |||
| Quercetin∗ | - | 8.3 (2.1) | 5.6 (0.9)e |
| Caffeic acid∗ | - | 11.2 (2.4) | 2.9 (2.0)e |
| Trolox∗ | - | 2.8 (1.8) | - |
aMean value (%RSD, relative standard deviation) of triplicate assays. bTotal phenolics data expressed as mg of gallic acid equivalents per g (mg of GAE/g). cDPPH assay data expressed as SC50 (concentration that inhibited 50% of the DPPH radical) in μg per mL. dORAC data expressed as μmol of Trolox equivalents per g (µmol of TE/g). eORAC data expressed as relative Trolox equivalent, mean (%RSD, relative standard deviation) of triplicate assays. ∗Experimental positive controls: not evaluated.