Ibrahim D.M.Jumal J.Harun F.W.2024-05-282024-05-2820151546923910.3844/ajassp.2016.1.62-s2.0-85000642931https://www.scopus.com/inward/record.uri?eid=2-s2.0-85000642931&doi=10.3844%2fajassp.2016.1.6&partnerID=40&md5=108bf7080f798d920661b46a09d5917fhttps://oarep.usim.edu.my/handle/123456789/85826-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.en-USBis-CoumarinsBreast cancerCytotoxic activityArticle161311.6