Table 1. DPPH scavenging activity of the 1,3,4-thiadiazole–chalcone hybrids 5a–m ^a .

Compound	IC50 ± SD (μM)
5a	12.03 ± 0.50
5b	11.66 ± 0.41
5c	17.17 ± 0.38
5d	11.81 ± 0.31
5e	9.76 ± 0.75
5f	10.33 ± 0.30
5g	17.86 ± 0.03
5h	13.91 ± 0.32
5i	17.82 ± 0.65
5j	18.04 ± 0.23
5k	14.01 ± 0.34
5l	13.45 ± 0.09
5m	11.06 ± 0.24
Ascorbic acid	20.23 ± 0.14

^aResults are mean values ± SD from three measurements.