Synthesis, structural, DNA/protein binding and cytotoxic studies of copper(I) ∝-diimine hydrazone complexes

[Display omitted] •Cu(I) complexes with α-diimine hydrazone ligands were designed, synthesized and characterized.•DNA/BSA binding and cytotoxic studies of the new Cu(I) complexes were evaluated.•The complex 4 shows better activity. A series of copper(I) complexes with α-diimine hydrazone ligands of the type [Cu(PPh3)2(L1-4)] (1–4) were synthesized by the reacting [Cu(CH3COO)(PPh3)2] with α-diimine ligands (L1-4) [L1 = 1, 2-bis(2-(benzothiazole-2-yl)hydrazineylidene)-1, 2-dihydro acenaphthylene (AQBH), L2 = 1, 2-bis(2-(quinolin-2-yl)hydrazineylidene)-1, 2-dihydro acenaphthylene (AQQH), L3 = 9, 10-bis(2-(benzothiazol-2-yl)dihydrazano)phenanthren-9,10-one (PQBH), L4 = 9,10-bis(2-(quinolin-2-yl)dihydrazano)phenanthren-9(10H)-one (PQQH)]. The new complexes were characterized by elemental analysis, UV–vis, FT-IR, 1H 13C NMR spectra and electrospray ionization-mass spectrometry (ESI-MS). Especially, the solid state structure of L1 (AQBH) was established using single crystal X-ray analysis. The interaction of complexes with CT-DNA was explored in detail using absorption and emission spectral methods to gain some insight into the structure–activity relationship. The obtained results revealed that complexes could interact with CT-DNA via intercalation. The interaction of these synthesized Cu (I) complexes with bovine serum albumin (BSA) was also evaluated using absorption and fluorescence techniques, which provided a static quenching mechanism between them. In addition, the cytotoxicity of compounds against HepG-2 (hepatic carcinoma) cancer and Vero normal (kidney epithelial cells extracted from an African green monkey) cells was evaluated by MTT assay. It was found that complex 4 (19.54 µM) exhibited potential activity towards HepG-2 cells which was more efficient than cisplatin (48.50 µM).