Synthesis, characterization, antibacterial and cytotoxicity studies on some mixed ligand Th(IV) complexes

Mixed ligand Th(IV) complexes of the type [M(Q)2LNO3.H2O] have been synthesized using 8-hydroxyquinoline (HQ) as a primary ligand and N- and/or O- donor amino acids (HL) such as L-alanine, L-phenylalanine, L-serine and L-tyrosine as secondary ligands. The metal complexes have been characterized on the basis of elemental analysis, electrical conductance, room temperature magnetic susceptibility measurements, spectral and thermal studies. The electrical conductance studies of the complexes in DMF at 10(-3) M concentration indicate their non-electrolytic nature. Room temperature magnetic susceptibility measurements revealed diamagnetic nature of the complexes. Electronic absorption spectra of the complexes show intra-ligand and charge transfer transitions, respectively. The thermal analysis data of the complexes indicate the presence of a coordinated water molecule. The tube dilution method has been used to study the antibacterial activity of the complexes against the pathogenic bacteria S. aureus and E. coli. The results have been compared against those of control tetracycline, which was screened simultaneously and indicate mild antibacterial activity of the complexes. The representative complex has been screened for cytotoxicity (IC50) studies against Ehrlich ascites cells and Daltons lymphoma ascites cells and shows low cytotoxic activity.