Synthesis and in vitro activity tests of N-benzoyl-N'-phenylthiourea derivatives as macrophage migration inhibitory factor

Context: The COVID-19 pandemic in 2020 resulted in widespread mortalities due to cytokine storms in the affected patients. Macrophage migration inhibitory factor (MIF) is one of the most interesting targets in developing anti-COVID-19 drugs. Some thiourea compounds have been identified as having potential as MIF inhibitors. Aims: To investigate MIF inhibitory activity of N-benzoyl-N'-phenylthiourea derivatives. Methods: The study consists of in-silico activity prediction of designed compounds using a molecular docking approach against MIF protein (PDB ID: 1LJT). Afterwards, the designed compounds were synthesized and tested in vitro using the tautomerase activity approach. Results: The molecular docking study showed that all designed compounds possess comparable docking scores to the native ligand of the protein. MIF Assay performed on compounds (1) and (2) indicated a decrease in tautomerase activity of the MIF target protein of only 10.1 and 6.2%, respectively, compared to the positive control. Conclusions: In silico results predicted better bioactivity against MIF protein, but the result does not translate to the in vitro assay, where two of the designed compounds possess only low inhibitory activity.