Synthesis, characterization and HSA interactions of a new piano-stool ruthenium(II) complex containing a thioamide-type ligand

Abstract

The synthesis and characterization of a newly synthesized piano-stool [Ru-(ɳ6-pcymene) Cl2L] complex with a ligand 3-amino-2-cyano-N-phenyl-3-(4-phenyl-1-piperazinyl)-2- propenethioamide are presented. The complex was obtained in good yield as an ochre powder and was characterized by elemental analysis, 1H and 13C NMR, IR, conductometry, and melting point. The fluorescence binding studies showed that the interaction of the complex with albumin occurs by a static quenching mechanism and that the complex showed a very high value of the binding constant with one binding site (Kb = 1.68 × 107; n = 1.37). In order to identify the binding location in the HSA molecule, competitive experiments with site markers (eosin Y (site I) and ibuprofen (site II)) were performed. Obtained results showed that the examined complex binds to the site I of subdomain IIA (for eosin Y: Kb = 5.94 × 102; n = 0.65 vs. for ibuprofen: Kb = 1.38 × 107; n = 1.34).