Structure and biological profile of transition metal complexes with (E)-4-(2-(pyridin-2-ylmethylene)hydrazinyl)quinazoline

The interaction of the recently reported quinazoline derivative (E)-4-(2-(pyridin-2-ylmethylene)hydrazinyl)quinazoline (L) with a series of metal(II) (= copper(II), nickel(II), cobalt(II) and cadmium(II)) chlorides or nitrates resulted in the formation of mononuclear complexes which were characterized by spectroscopic techniques and single-crystal X-ray crystallography, i.e. [Cu(L)2]Cl2·4H2O (1·4H2O), [Ni(L)2]Cl2·4H2O (2·4H2O), [Ni(L)2](NO3)2·MeOH (3·MeOH), [Co(L)2]Cl2·4H2O (4·4H2O), [Co(L)2](NO3)2·H2O (5·H2O), [Co(L)2](NO3)3·2.5H2O (6·2.5H2O), [Cd(L)(Cl)2]·H2O (7·H2O) and [Cd(L)(CH3OH)(H2O)(NO3)](NO3) (8). The biological profile of the complexes was further assessed in regard to their binding affinity with calf-thymus DNA, their cleavage ability towards pBluescript II KS plasmid DNA in the absence or presence of irradiation of various wavelengths, their interaction with bovine serum albumin and finally, their ability to scavenge 1,1-diphenyl-picrylhydrazyl and 2,2΄-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) radicals and to reduce H2O2.