6-hydroxy-4-methyl-5,7-(bis-p-chlorophenylazo)coumarin has been synthesized and characterized by CHN elemental analysis, FTIR,1H-NMR-spectroscopy and mass-spectral data. Cytotoxic screening by MTT assay was carried out on the compound against breast cancer cells. The overall results from preliminary screening program revealed that the cell proliferation was highly inhibited by 6-hydroxy-4-methyl-5,7-(bis-p-chlorophenylazo) coumarin with the value of 2.81%, at concentration of 30 ?g mL?1 compared with the untreated control cells and also possessed a good chelating activity with IC50 value 1.87 ?g mL?1. It is suggested that the cytotoxic activity is affected by hydroxyl and halogen groups as these groups have high electron affinity and high electronegativity. � 2016 Dalal M. Ibrahim, Juliana Jumal and Farah Wahida Harun.

Background/Objectives: One of the severe disease intimidating human health and continues to be a main health problem worldwide is cancer. Hence, discovering new compounds with powerful anticancer activity is of extreme important. The main objective of this paper is the synthesize 6-hydroxy-4-methyl-5,7-(bis-phenylazo) coumarin and its complexes and evaluate the cytotoxic activity of the ligand and complexes against breast cancer cells. Methods/Statistical Analysis: A novel compounds of 6-hydroxy-4-methyl-5,7-(bis-phenylazo) coumarin have been synthesized by 6-hydroxy-4-methylcoumarin. The complexation of nickel (II), copper (II) and cobalt (II) using this ligand gave salt type complexes with the formula of M(C22H15O3N4) the compounds were characterized by microelemental analysis, infra-red, nuclear magnetic resonance spectroscopic techniques and molar conductivity. Cytotoxic activity for the ligand and the complexes were evaluated against breast cancer cells by using MTT assay and the absorbance at 570 nm was measured by ELISA reader. Findings: The CHN analysis of the compounds are in good agreement with the calculated values and the spectroscopic analysis of the complexes indicated that the ligand coordinated to the metal centres as polydentate ligand in bisazocoumarin and form a distorted octahedral arrangement around nickel (II), copper (II) and cobalt (II) centres. The molar conductivity of the divalent metal ions complexes was small which directly supports the fact that all of the investigated complexes are non ionic. The overall results of cells MCF7 breast cancer revealed of cell proliferation was much more highly inhibited by the ligand and complexes Cu, Co and Ni with cell viability 5.21%, 17.36%, 46.20% and 74.43%, respectively at a concentration of 30 mg/ml compared to untreated control cells and IC50 values of the ligands and complexes of Cu, Co and Ni were 1.87, 1.87, 30 and >30 g/ml, respectively. Improvements: Lastly, some suggestions were presented to use these compounds in vivo should be assessed to obtain worthy anticancer drugs.