Medium Controlled Stoichiometric Complexation of Penicillin G—Potassium Drug with Se(IV), Nb(V), Ta(V), and Te(IV) Chlorides: Physicochemical and Antitumor Activity of the Complexes

Abstract

Four new 1: 1 ratio of Se⁺⁴, Nb⁺⁵, Ta⁺⁵, and Te⁺⁴ penicillinate complexes are synthesized in the reaction of penicillin potassium salt (Pin-G-K) with Se(IV), Nb(V), Ta(V), and Te(IV) chlorides. Structures of the synthesized complexes are characterized by elemental analysis, conductivity, magnetic susceptibility, IR, UV-Vis, ¹H and ¹³C NMR, and mass spectra, SEM, TEM, and XRD. Diamagnetic and electronic spectral studies allow to elucidate the geometry of penicillinate chelates around central metal ions. The monomeric structures of Pin-G complexes with six or eight coordinated metal ions are proposed. The metal ions are coordinated toward Pin-G as tridentate chelates via the amide and β-lactam carbonyl, and monodentate carboxylate groups. According to powder XRD the complexes have crystalline to poly crystalline nature. In vitro antimicrobial activity of Pin-G complexes is tested against four bacteria pathogens: G⁻ (Klebsiella and Escherichia coli) and G+ (Staphylococcus epidermidis and Staphylococcus aureus). Anti-tumor activity of the Pin-G complexes is assessed against human hepato cellular carcinoma (HepG-2) and human breast cancer (MCF-7) tumor cell lines.