Synthesis, spectroscopic studies of novel N-substituted phthalimides and evaluation of their antibacterial, antioxidant, DNA binding and molecular docking studies

Abstract

A new series of N-substituted phthalimide derivatives were prepared by condensation of appropriate amount of n-amino tetrachlorophthalimide with respective aldehyde in glacial acetic acid. The structural investigation of the synthesized compounds was done by spectroscopic methods (UV-Vis., IR, ¹H and ¹³C NMR) and elemental analysis. The antibacterial screening of these compounds was performed against Escherichia coli and Staphylococcus mutans. The synthesized compounds were evaluated for their antioxidant potential using 2,2-diphenyl-1-picrylhydrazyl (DPPH) as a scavenging agent. The interaction ability of most promising compounds (3a and 3b) with native calf thymus DNA (Ct-DNA) was also studied by means of UV-Vis., circular dichroism (CD), viscosity measurements and thermal studies. The intrinsic binding constants (K_b) of 3a and 3b with Ct-DNA obtained from UV-Vis. absorption studies were 8 × 10⁴ and 1 × 10⁵, respectively. Molecular docking of target compounds (3a and 3b) against DNA dodecamer d(CGCGAATTCGCG)₂ has been carried out. The test compounds exhibited remarkable antibacterial, antioxidant and DNA binding activities.