Spectroscopic, DFT analysis, antimicrobial and cytotoxicity studies of three gold(III) complexes

Abstract

Three gold(III) complexes were synthesized using 2-pyrazinecarboxamide, pyridine or bipyridine ligand. Complexes were characterized by spectroscopic and analytical techniques (IR, Raman, 1H NMR, mass spectrometry and elemental analysis). Thermogravimetry and conductivity of complexes were investigated. IR, Raman and theoretical calculations of spectral modes of vibrations using DFT and MP2 methods were performed. Biological activities of the complexes against two bacteria Escherichia coli and Staphylococcus aureus and two fungi Aspergillus flavus and Candida albicans were screened. They exhibited activities toward both bacteria and fungi. Potency assays of the complexes against two breast cancer and liver carcinoma cell lines were evaluated. They exhibited in vitro activities toward the tumors relative to cis-platin. In addition, fluorescence quenching studies viscosity measurements of the complexes are performed. Theoretical calculations based on accurate DFT were established to verify the optimized structures of complexes. Global chemical reactivity descriptors were estimated from energy of HOMO and LUMO orbitals.

Keywords:

• Pyrazine derivatives
• gold complexes
• IR and Raman studies
• DFT studies
• anticancer drugs

Supplementary Materials

Experimental and calculated IR and Rarman spectra (S1-–S3) are provided as supplementary materials.