The effect of metal and substituent on DNA binding, cleavage activity, and cytotoxicity of new synthesized Schiff base ligands and Zn(II) complex

New water soluble Schiff base ligands [N,Nʹ-bis{5-[(triphenylphosphonium percholorate)-methyl]salicylidine}-1,3-diamino-2-propanol] (L1) and [N,Nʹ-bis(salicylidine)-1,3-diamino-2-propanol] (L2) and zinc (II) complex of L1: [N,Nʹ-bis{5-[(triphenylphosphonium percholorate)-methyl]salicylidine}-1,3-diamino-2-propanol]Zn(II) were synthesized and characterized by elemental analysis, FT-IR, 1HNMR and UV-Vis spectroscopy. In vitro DNA binding of the compounds were investigated by UV-Vis absorption spectroscopy, viscosity measurement, cyclic voltammetry, fluorescence spectroscopy, and gel electrophoresis. The present study aimed to investigate the effect of metal and substituent on DNA binding, cleavage activity and cytotoxicity of new synthesized Schiff base ligands and Zn(II) complex. The order of DNA binding affinity (Kb) calculated from the absorption spectroscopy was: ZnL1 > L2 > L1. Molecular docking studies explore more details on the mode of binding and binding energies. Although the compounds revealed strong DNA binding affinity but electrophoresis studies don't show any effects on the DNA structure and single or double strand breaks. The cytotoxicity experiments against human Hepatoma (HepG2) showed the order: L1 > ZnL1 > L2.