Synthesis, Physicochemical, and Biological Studies of New Pyridoxine HCl Mononuclear Drug Complexes of V(III), Ru(III), Pt(II), Se(IV), and Au(III) Metal Ions

Abstract

Pyridoxine HCl (vitamin B₆; Pyr-H₃) complexes with the formula [M(Pyr-H)(H₂O)₄].Cl·nH₂O [M= V(III), Ru(III); n = 0.1], [Pt(Pyr-H)(H₂O)(Cl)].Cl, [Se(Pyr-H₃)(O)(OH)₂], and [Au(Pyr-H)(H₂O)₂]·Cl are synthesized by the reactions of Pyr-H₃ with metal chlorides [V(III), Ru(III), Pt(II), Se(IV), and Au(III)] at 60°C in methanol–water 50: 50 v/v. The accumulated data of the elemental analysis, conductivity measurements, mass, FT-IR, ¹H, and ¹³C NMR, UV-Vis spectroscopy and magnetic moments support elucidated stoichiometry, structures and chelation of the complexes. Thermogravimetric analysis of the synthesized solid complexes is carried out for determining their thermal stability, number of crystalline water molecules and decomposition steps. According to the physicochemical analyses Pyr-H₃ reacts with metal ions as a bidentate ligand via both phenolate oxygen and oxygen of the CH₂OH group. The antimicrobial and anticancer tests reveal that complexes demonstrate higher antibacterial activity than free Pyr-H₃ chelate. According to the cytotoxic results of Pt(IV) and Au(III) complexes in vitro based on human hepato cellular carcinoma (HepG-2) and human breast cancer (MCF-7) tumor cell lines, the former one exhibits promising activity.