Table 1.

DPPH scavenging activity at 25 μM (mean value and standard deviation) and IC₅₀ values of the tested compounds and ascorbic acid as positive control.

Compound *	IC50 μM (at 60 min)	DPPH Reduction Activity (%) at 25 μM (at 60 min)
1	28.4 ± 0.2 a	43.3 ± 1.5 a
2	31.2 ± 4.8 a	36.8 ± 4.9 a,b
3	47.3 ± 0.4 b	24.9 ± 1.3 c
4	Not determined	34.6 ± 3.2 b,d
5	Not determined	9.2 ± 2.4 e
Ascorbic Acid	40.0 ± 0.8 c	28.9 ± 0.3 c,d

* Compounds 1, 2, and 3 were dissolved in ethanol 70%. Due to low solubility in ethanol 70%, compounds 4 and 5 were dissolved in a solution of ethanol 70% with 1% DMSO. In each column, different letters indicate significant differences (p < 0.05).