LAUSR

New lanthanide complexes (1-3) of the general formulae [Ln(L)(NO3)(H2O)] have been synthesized by reaction of Ln(NO3)3.xH2O {Ln = La (1), Sm (2) and Yb (3)} with 2,2'-(((1E,1'E)-thiophene-2,5-diylbis(methaneylylidene))bis(azaneylylidene))diphenol (H2L). Based on elemental analysis and spectroscopic analysis (UV-Visible, FT-IR, ESI-MS 1H and 13C NMR), molar conductance and thermogravimetric analysis. The results showed that the Schiff base ligand coordinated Ln(III) ions through the azomethine nitrogens, deprotonated hydroxyl groups, and thiophene sulphur atom. The interaction of the synthetic compounds with CT-DNA has been studied to investigate their anticancer activitiy by the electronic spectroscopy, fluorometric competition studies with ethidium bromide and DNA viscosity measurements. Furthermore, due to the ligand and its Ln(III) complexes exhibit good DNA binding affinity, it is considered worthwhile to investigate their antioxidant activity. The data have shown that, the complexes are more effective inhibitors towards reactive oxygen species (ROS), such as superoxide anion and hydroxyl radical. The activity of test compounds in ascending order (1) > (2) > (3) > H2L in terms of IC50 value. The anticancer activities of the complexes have also been studied towards human colon carcinoma cancer (HCT-116) and human breast cancer (MCF-7) cell lines.