Synthesis, antibacterial and free radical scavenging activity of some newer N-((10-nitro-1H-indolo [1, 2-c]quinazolin-12-yl)methylene)benzenamines

Present research is oriented on the synthesis of some novel 12-(N-arylmethaniminyl)indolo[1,2-c]quinazoline analogs (4b1–4b11) and their characterization by ¹H NMR, ¹³C NMR, FTIR and mass spectrophotometry. Their free radical scavenging activity and antibacterial potential were also evaluated. Many derivatives have shown a marked free radical scavenging capacity in all the concentrations but specifically compounds 4b7, 4b8 and 4b11 have shown good antioxidant potential with an IC₅₀ value of 25.18 μmol/L, 28.09 μmol/L & 44.22 μmol/L, respectively (DPPH method) and 39.46 μmol/L, 44.47 μmol/L & 35.61 μmol/L, respectively (H₂O₂ method). The antibacterial evaluation was carried out against B. subtilis and E. coli by agar well diffusion method and it revealed that all the compounds in the series were having marked antibacterial activity but compounds 4b9 and 4b11 have shown best antibacterial potential. Then, it was concluded that the derivatives which were containing substituted anilines (4-Nitro, 4-Fluoro, 4-Bromo & 4-Chloro-2-nitro) on the carbon attached on the 12^th position of indoloquinazoline moiety were having marked potential as an antibacterial and free radical scavenger.