New ruthenium(II)-arene complexes bearing hydrazides and the corresponding (thio)semicarbazones of 3- and 4-acetylpyridine: Synthesis, characterization, crystal structure determination and antiproliferative activity

Abstract

Metal semicarbazone and thiosemicarbazone complexes have attracted much attention due to their diverse biological activities. Because of the ability of ruthenium(II)-arene species to coordinate to different classes of ligands, they are suitable for fine-tuning chemical and pharmaceutical properties. Ruthenium(II) arene-complexes containing different types of ligands: namely caprylic hydrazide (a hydrazide with a long hydrocarbon chain), isonicotinic acid hydrazide (a hydrazide with an aromatic pyridine ring), thiosemicarbazones and semicarbazones (derived from the reaction of 3- and 4-acetylpyridine with either thiosemicarbazide or caprylic hydrazide), were obtained in the reaction of [(η6-p-cymene)RuCl2]2 with the corresponding ligands in a 1:2 or 1:2.2 molar ratio in methanol, ethanol or isopropanol with mild heating. The complexes were characterized by elemental analysis, mass spectrometry, IR and NMR spectroscopies. The structure of complex 1 was determined by X-ray crystallography. Antiproliferative activity of the investigated complexes, determined for three human cancer cell lines (HeLa, A549 and LS-174) revealed moderate activity without significant influence on the matrix metalloproteinases (MMP-2 and MMP-9) activity.