Synthesis and evaluation of antibacterial and antioxidative activities of carbazole derivatives

Seven compounds were synthesized by known methods, and their antibacterial activity was evaluated against Bacillus subtilis and Escherichia coli using a disk diffusion method. Antioxidative activity was evaluated using free 1,1-diphenyl-2-picryl-hydrazyl radical scavenging assay and ferric reducing antioxidant power methods. The disk diffusion method revealed that 6 out of 7 tested compounds showed antibacterial activity against tested strains, they inhibited the growth of bacteria at various concentrations, from 31.25 to 250 μg/ml. 3-Cyano-9H-carbazole, 3-iodo-9Hcarbazole and 3,6-diiodo-9H-carbazole showed a stronger antibacterial activity against Bacillus subtilis compared to the reference drug amoxicillin. 1,3,6-Tribromo-9H-carbazole showed a stronger activity against Escherichia coli. All tested compounds showed a weak antioxidative activity by the 1,1-diphenyl-2-picryl-hydrazyl radical scavenging assay and ferric reducing antioxidant power assay methods.