Synthesis and evaluation of in vitro antioxidant capacities of some benzimidazole derivatives

Figures & data

Scheme 1 Synthesis of compounds 1a–f.

Table I.  Physical properties of compounds 1a–f.

Comp.	R1	R2	Yield (%)	Mp (^oC)	Molecular Formula
1a		–COOH	20	315–317	C17H17N2O2Cl
1b	CH2SH	–COOH	29	310	C9H9N2O2ClS
1c	(CH2)2–NH2	–COOH	16	300–302	C10H12N3O2Cl
1d		–COOH	20	290	C16H21N2O2Cl
1e			43	295	C22H17N3O3
1f			14	297	C22H17N4O4

Figure 1 Dose-dependent inhibitory effect of benzimidazoles on H₂O₂-induced lipid peroxidation in erythrocyte membranes. Data are expressed as mean ± SE of 3–8 incubations.

Figure 2 In vitro effect of melatonin and benzimidazole derivatives on SOD activity from human erythrocytes. 1a-f was added at 0.5mM concentration to the incubation media. Values represent means from at least 3 different incubations ± SEM.

Figure 3 In vitro effect of melatonin and benzimidazole derivatives on catalase activity from human erythrocytes. 1a-d was added at 0.5mM, 1e at 0.02mM and 1f at 0.01mM concentration to the incubation media. Values represent means from at least 3 different incubations ± SEM.

Figure 4 In vitro effect of melatonin and benzimidazole derivatives on G6PD activity from human erythrocytes. 1a-d was added at 0.5mM, 1e at 0.02mM and 1f at 0.01mM concentration to the incubation media. Values represent means from at least 3 different incubations ± SEM.

Figure 5 The interrelationships between antioxidant enzymes in detoxification of reactive oxygen species.