Copper-paracetamol complexes: Promising lead antibacterial drug candidates

Abstract

Antibiotic resistance by microorganisms has triggered the need to discover new antibiotics to replace the old ones. The study was designed to prepare copper-paracetamol complexes which will serve as lead compounds towards the discovery of novel antibiotics. Copper sulphate was reacted with paracetamol in the presence of sodium nitrate in borate buffer to give products which were separated into three layers when extracted with a set of organic solvents. The topmost, third layer was separated and further washed with 1:1:1 petroleum ether, ethanol and benzene to obtain a yellow extract. The first and second layers were also air dried to obtain products 1 and 2. The maximum wavelength of absorption of products 1, 2, yellow extract and paracetamol were 250, 350, 280 and 300 nm respectively. The infrared absorption peaks suggested that, the metal coordination products formed were different from the reactants (paracetamol and cupper). The atomic absorption spectra of the extracts further indicated the association of copper with paracetamol to form the coordination complexes. Products 1, 3 and the yellow extract inhibited E. coli and staphylococcus growth. In all four products were separated and their possible structures have been proposed in the text.   Key words: Copper, paracetamol, coordination complex, antibacterial and drug leads.