Density functional theory study of gold(III)-dithiocarbamate complexes with characteristic anticancer potentials.

The application of gold as drug candidate dated back to 2500 BC and its relevance in medicine became more appealing following 1985 FDA approval of ingested Auranofin for the treatment of rheumatoid arthritis. In this study, we have provided a density functional theory (DFT) study of some gold(III)-dithiocarbamate complexes with characteristic anticancer potentials. DFT calculation of the reactivity and selectivity properties of these complexes with an enzyme template of thioredoxin reductase (TrxR) was carried out. The investigation proceeds with theoretical characterization of the selected compounds through spectroscopic analyses. IR and UV-vis analyses were carried out and the calculated values are comparable to experimental results. NMR assignment was determined for the gold compounds and the estimated theoretical chemical shift values agree with available experimental data from literature. The obtained DFT-based chemical parameters proved to be significant in evaluating the selectivity, reactivity and stability of the gold(III) complexes as potential anticancer moieties, specifically against TrxR. Calculated binding free energy gave similar order with the available in vitro inhibition profile of these gold(III)-dithiocarbamate complexes against TrxR. The outcome of this DFT study could serve as a useful guide towards future design of new and potent anticancer drug candidate. The investigated chemical reactivity properties could be considered and applied to a wide range of bioactive compounds and enzyme-inhibitor systems.