Bimetallic bis -Aroyldihydrazone-Isatin Complexes of High O=V(IV) and Low Cu(II) Valent Ions as Effective Biological Reagents for Antimicrobial and Anticancer Assays.

Due to the versatile bioreactivity of aroyldihydrazone complexes as cost-effective alternatives with different transition metals, two novel bimetallic homo-complexes (VOLph and CuLph) were prepared via the coordination of a terephthalic dihydrazone diisatin ligand (H 2 Lph) with VO 2+ and Cu 2+ ions, respectively. The structure elucidation was confirmed by alternative spectral methods. Biologically, the H 2 Lph ligand and its MLph complexes (M 2+ = VO 2+ or Cu 2+ ) were investigated as antimicrobial and anticancer agents. Their biochemical activities towards ct DNA (calf thymus DNA) were estimated using measurable titration viscometrically and spectrophotometrically, as well as the gel electrophoresis technique. The growth inhibition of both VOLph and CuLph complexes against microbial and cancer cells was measured, and the inhibition action, MIC, and IC 50 were compared to the inhibition action of the free H 2 Lph ligand. Both VOLph and CuLph showed remarkable interactive binding with ct DNA compared to the free ligand H 2 Lph, based on K b = 16.31, 16.04 and 12.41 × 10 7 mol -1 dm 3 and ΔGb≠ = 47.11, -46.89, and -44.05 kJ mol -1 for VOLph, CuLph, and H 2 Lph, respectively, due to the central metal ion (V IV O and Cu II ions). VOLph (with a higher oxidation state of the V 4+ ion and oxo-ligand) exhibited enhanced interaction with the ct DNA molecule compared to CuLph, demonstrating the role and type of the central metal ion within the performed electronegative and electrophilic characters.