New copper(II) and oxidovanadium(IV) complexes with a vitamin B Schiff base: mechanism of action and synergy studies on 2D and 3D human osteosarcoma cell models.

We report the synthesis, characterization and anticancer activity of a new Schiff base (HL) derived from the condensation of pyridoxamine with pyridoxal and its novel copper(II) and oxidovanadium(IV) complexes: [Cu(HL)Cl] (1), [Cu(LH)(phen)]Cl (2), [Cu(LH)(amphen)]Cl (3), [VO(HL)Cl] (4), and [VO(LH)(phen)]Cl (5), where phen is 1,10-phenanthroline and amphen is its 5-amino derivative. All compounds were characterized by analytical and spectroscopic techniques, namely FTIR, UV-vis and EPR spectroscopy. Their stability in aqueous media was evaluated, revealing that the presence of the phen co-ligand significantly increases the stability.