Entry Compound No. Inhibition %
1 Vit. C 71.3
2 2 79.3
3 3 39
4 4 52
5 5 77.5
6 6 66.5
7 7 51.0
8 8 55.2
9 9 47.1
10 10 76
11 11 79.6
12 12 51
13 13 22
14 16 26.3
15 17 15.6
16 18 79
17 20 77.1
18 21 82.8
19 22 80.5
Table 1: Free radical scavenging capacities of naphthoquinone derivatives 2-22 measured in NBT assay at a dose 1000 μg/mL.