Investigation of DNA binding and molecular docking propensity of phthalimide derivatives: in vitro antibacterial and antioxidant assay

A series of N-substituted tetrabromphthalimide derivatives was synthesized by condensation reaction using tetrabromophthalic anhydride with 3,5-diamino-1,2,4-triazole/ 2,6-diaminopyridine/ 2,6-diamino-4-hydroxy pyrimidine/ o-tolidine. All the synthesized phthalimide derivatives were characterized by elemental analysis, infrared, and NMR spectroscopy. In vitro antibacterial evaluation was carried out for the synthesized compounds. Results revealed that compound 1 showed potential activity against Escherichia coli (100 μg/mL) and Streptococcus mutans (150 μg/mL). On the basis of antibacterial activity, compound 1 was selected for DNA binding interaction, though DNA target most of the antibacterial drugs. The DNA binding modes of the compound 1 with Ct-DNA (calf thymus) were studied by absorption measurements, hydrodynamic measurements and cyclic voltammetry methods. Molecular docking also confirms that compound 1 recognizes both the strands of the DNA dodecamer d(CGCGAATTCGCG)2 within minor groove and showing the best binding capability with the duplex. Compound 1 also showed better antioxidant activity by 2,2-diphenyl-1-picryl-hydrazyl (DPPH) free radical and hydrogen peroxide.