CT DNA, BSA and Antiproliferative Activity of Ru(II) Bipyridine Complexes Containing Schiff Bases Derived from Amino Acids

Abstract

Complexes of general formula [Ru(bpy)2(L)]CF3SO3, where bpy = 2,2'-bipyridine, and L = Schiff bases derived from salicylaldehyde and amino acids (glycine (1a), cysteine (1b), methionine (1c) and phenylalanine (1d)) were synthesized. Characterization based on elemental analysis, Ru content, mass, infrared and electronic spectra confirmed RuN5O coordination unlike 1b where coordination occurred via azomethine nitrogen and cysteine sulfur. Cyclic voltammograms, except 1b, showed several quasi-reversible redox pairs in the positive potential range, the first located at about 0.5 V, corresponding to similar heteroleptic Ru(II) bipyridyl complexes. Biological activity was tested by interactions with DNA and BSA. DNA binding constants of order 103M-1, suggest groove binding due to bpy ligand and hydrogen bonding of the OH and CO groups from the imine moiety. In vitro BSA protein inhibition assay performed by spectrofluorimetry showed Complex : BSA binding in 1 : 1 ratio with Kbof 104M-1order. Cytotoxicity studies by MTT assay for 72 h of drug action revealed activity of 1a and 1d against breast cancer MCF-7 cells with IC50values 32 ± 8 and 26 ± 1μM, respectively.