Table 1.

Antioxidant activity of sulphonamides 2 and 3.

			IC50 (µM)a
			DPPH free radical	ABTS cation radical	Metal chelating
Comp.	R1	R2	Scavenging activity	Scavenging activity	Activity
2a	–4F	Cl	469.75 ± 1.17	>1000	488.29 ± 0.84
2b	–4MeO	Cl	500.97 ± 1.17	>1000	164.26 ± 0.68
2c	–3,4diCl	Cl	304.52 ± 1.38	>1000	109.63 ± 0.80
2d	–3NO2	Cl	443.26 ± 1.38	>1000	296.78 ± 0.52
3a	–4F	–N(Me)2	>1000	>1000	84.98 ± 1.14
3b	–4F		73.25 ± 0.52	>1000	148.03 ± 0.61
3c	–4F		>1000	>1000	338.90 ± 0.59
3d	–4MeO	–N(Me)2	102.65 ± 1.17	294.12 ± 1.20	337.51 ± 0.55
3e	–4MeO		>1000	>1000	84.32 ± 0.39
3f	–4MeO		>1000	408.44 ± 1.67	98.84 ± 0.90
3g	–3,4diCl	–N(Me)2	609.35 ± 0.98	>1000	139.15 ± 1.15
3h	–3,4diCl		60.18 ± 0.59	>1000	147.60 ± 0.82
3i	–3,4diCl		351.97 ± 1.33	>1000	99.10 ± 0.52
3j	–3NO2	–N(Me)2	58.59 ± 0.12	>1000	98.84 ± 0.90
3k	–3NO2		336.28 ± 1.43	481.21 ± 0.97	88.42 ± 0.75
3l	–3NO2		114.38 ± 0.60	>1000	115.46 ± 0.87
BHAb	–	–	61.72 ± 0.85	45.40 ± 1.08	–
BHTb	–	–	232.11 ± 3.01	26.54 ± 0.18	–
α-Tocopherolb	–	–	56.86 ± 0.77	34.12 ± 0.41	–
EDTAb	–	–	–	–	52.35 ± 1.15

^aIC₅₀ values represent the means (standard deviation of three parallel measurements (p < 0.05).

^bReference compounds.