Synthesis and evaluation of new salicylaldehyde-2-picolinylhydrazone Schiff base compounds of Ru(II), Rh(III) and Ir(III) as in vitro antitumor, antibacterial and fluorescence imaging agents.

Reaction of salicylaldehyde-2-picolinylhydrazone (HL) Schiff base ligand with precursor compounds [{(p-cymene)RuCl2}2] 1, [{(C6H6)RuCl2}2] 2, [{Cp*RhCl2}2] 3 and [{Cp*IrCl2}2] 4 yielded the corresponding neutral mononuclear compounds 5-8, respectively. The in vitro antitumor evaluation of the compounds 1-8 against Dalton's ascites lymphoma (DL) cells by fluorescence-based apoptosis study and by their half-maximal inhibitory concentration (IC50) values revealed the high antitumor activity of compounds 3, 4, 5 and 6. Compounds 1-8 render comparatively lower apoptotic effect than that of cisplatin on model non-tumor cells, i.