Ruthenium(II)-arene complexes with functionalized pyridines: Synthesis, characterization and cytotoxic activity

Abstract

Ruthenium(II)-arene complexes of general formulae [(eta(6)-p-cymene)Ru(L1-3)Cl-2], where L1-3 is 3-acetylpyridine (1), 4-acetylpyridine (2) and 2-amino-5-chloropyridine (3), Correspondingly, [(eta(6)-p-cymene)Ru(HL4,5)Cl-2], where HL4 and HL5 are respectively isonicotinic acid (4) and nicotinic acid (5) and [(eta(6)-p-cymene)Ru(HL6-9)Cl], where H2L6-9 represent 2,3-pyridinedicarboxylic acid (6), 2,4-pyidinedicarboxylic acid (7), 2,5-pyridinedicarboxylic acid (8) and 2,6-pyridinedicarboxylic acid (9), were prepared by the reaction of (eta(6)-p-cymene)(2)RuCl2](2) (10) with the corresponding ligand in 1:2 molar ratio in isopropanol. The complexes were characterized by elemental analysis, mass spectrometry, IR and NMR spectroscopies. According to these data the molecules adopt the usual "three-leg piano-stool" geometry which is common for this type of complexes. The structures of I and 7 were determined by X-ray crystallography. The complexes revealed low antiproliferative activity in six investigated tumor cell lines (HeLa, B16, FemX, MDA-MB-361, MDA-MB-453 and LS-174). The reaction of 6 with 9-methyladenine was studied by H-1 NMR, H-1, H-1 COSY and H-1, H-1 NOESY spectroscopy.