Table 2.
Antioxidant activity of compounds 1–23.
| Compounds | DPPH SC50 (μM) a | FRAP Value (μM) b |
|---|---|---|
| 1 | 400.8 ± 25.9 | 28.8 ± 0.9 |
| 2 | 11.3 ± 1.6 | 336.9 ± 17.0 |
| 3 | >500 c | n.d. d |
| 4 | 6.0 ± 0.3 | 139.5 ± 5.0 |
| 5 | 487.1 ± 25.6 | 18.2 ± 0.5 |
| 6 | 10.8 ± 1.2 | 367.1 ± 23.7 |
| 7 | >500 | n.d. |
| 8 | 9.6 ± 0.7 | 379.6 ± 5.2 |
| 9 | >500 | n.d. |
| 10 | 265.4 ± 12.7 | 19.6 ± 0.6 |
| 11 | >500 | n.d. |
| 12 | 14.5 ± 2.3 | 371.3 ± 14.8 |
| 13 | >500 | n.d. |
| 14 | 380.4 ± 22.7 | 35.8 ± 1.0 |
| 15 | 450.8 ± 16.9 | 47.3± 1.2 |
| 16 | >500 | n.d. |
| 17 | >500 | n.d. |
| 18 | >500 | n.d. |
| 19 | 21.3 ± 0.4 | 111.3 ± 1.5 |
| 20 | 27.5 ± 1.3 | 102.5 ± 3.9 |
| 21 | 393.9 ± 11.8 | n.d. |
| 22 | 147.0 ± 8.1 | 12.3 ± 0.6 |
| 23 | 86.1 ± 5.8 | 52.3 ± 1.2 |
| Ascorbic acid | 16.3 ± 0.7 | 417.4 ± 9.8 |
a SC50 is expressed as the concentration of sample needed to scavenge 50% of DPPH radical; data are represented as mean ± SD; b The FRAP value is the concentration of sample (μM) giving an absorbance increase equivalent to 1 mM Fe2+ solution; data are represented as mean ± SD; c The SC50 value of sample is higher than 500 μM; d n.d. Not detectable.