Synthesis, X-ray structure, <i>in vitro</i> HIV and kinesin Eg5 inhibition activities of new arene ruthenium complexes of pyrimidine analogs

<p>Three new ruthenium(II)-arene complexes of the general formula [{(η⁶-<i>p</i>-cymene)Ru(L)}₂](Cl)₂), where L are monastrol (<b>L</b>^<b>1</b>), ethyl 4-(3-hydroxyphenyl)-6-methyl-2-thioxo-pyrimidine-5-carboxylate (<b>L</b>^<b>2</b>) or its 4-bromophenyl analog (<b>L</b>^<b>3</b>), have been synthesized and characterized by elemental analysis, ¹H, ¹³C, and 2-D NMR spectroscopy. The X-ray diffraction study of complex <b>1</b> showed the presence of a dicationic diruthenium complex where two thioxopyrimidines act as tridentate <i>μ,κN:κ</i>^<i>2</i><i>S</i> ligand, bridging two Ru ions through the pyrimidine nitrogen and sulfur atoms. All new complexes were evaluated <i>in vitro</i> for their antiviral activity against the replication of HIV-1 and HIV-2 in MT-4 cells using MTT assay. Additionally, complexes <b>1</b>–<b>3</b> were screened for their inhibitory activity against the ATPase enzyme and the motor-protein Kinesin Eg5. Complex <b>1</b> was found to inhibit microtubule-stimulated ATPase activity of kinesin of IC₅₀ = 30 μM (monastrol, IC₅₀ = 10 μM).</p