Bidentate Schiff Base Ligands Appended Metal(II) Complexes as Probes of DNA and Plasma Protein: In Silico Molecular Modelling Studies.

HL1 and HL2 (HL1 = 5-diethylamino-2-({[4-(diethylamino)phenyl]imino}methyl)-phenol; HL2 = 5-diethylamino-2-({[4-(dimethylamino)phenyl]imino}methyl)-phenol) are new Schiff base ligands which were prepared along with their metal(II) complexes of [Cu(L1)] (1), [Cu(L1)] (2), [Ni(L2)] (3) and [Ni(L2)] (4) and characterized by different analytical as well as spectroscopic analyses. The single crystal XRD analysis confirms the proposed structure of ligands such as HL1 and HL2. EPR spectral analysis gives evidence about the tetrahedrally coordinated geometry of complexes 1 and 2. Density functional theory (DFT) analysis was executed using B3LYP/6-31G(d,p)∪LanL2DZ level. The DNA sequence (along with Dickerson's sequence) specificity of complexes 1-4 was evaluated and it has resulted that the complexes 1-4 primarily interact with double helix of DNA via groove mode of binding. From plasma protein docking results, we can say that complexes 2 and 4 showed more binding towards HSA and may have good bioavailability and are prone to act as drug candidates. The observed findings show that these metal(II) complexes 1-4 are better DNA probes, will act as anticancer agents and stimulate strong research focusing on the design of new chemical probes of DNA.