title: Synthesis, characterization and biological evaluation of transition metal complexes derived from N, S bidentate ligands.
abstract: Two bidentate NS ligands were synthesized by the condensation reaction of S-2-methylbenzyldithiocarbazate (S2MBDTC) with 2-methoxybenzaldehyde (2MB) and 3-methoxybenzaldehyde (3MB). The ligands were reacted separately with acetates of Cu(II), Ni(II) and Zn(II) yielding 1:2 (metal:ligand) complexes. The metal complexes formed were expected to have a general formula of [M(NS)2] where M = Cu2+, Ni2+, and Zn2+. These compounds were characterized by elemental analysis, molar conductivity, magnetic susceptibility and various spectroscopic techniques. The magnetic susceptibility measurements and spectral results supported the predicted coordination geometry in which the Schiff bases behaved as bidentate NS donor ligands coordinating via the azomethine nitrogen and thiolate sulfur. The molecular structures of the isomeric S2M2MBH (1) and S2M3MBH (2) were established by X-ray crystallography to have very similar l-shaped structures. The Schiff bases and their metal complexes were evaluated for their biological activities against estrogen receptor-positive (MCF-7) and estrogen receptor-negative (MDA-MB-231) breast cancer cell lines. Only the Cu(II) complexes showed marked cytotoxicity against the cancer cell lines. Both Schiff bases and other metal complexes were found to be inactive. In concordance with the cytotoxicity studies, the DNA binding studies indicated that Cu(II) complexes have a strong DNA binding affinity.
authors.affiliation: Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, UPM Serdang 43400, Malaysia. enisnadia89@gmail.com.
authors.forename: Enis Nadia
authors.initials: EN
authors.lastname: Md Yusof
authors.affiliation: Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, UPM Serdang 43400, Malaysia. thahira@upm.edu.my.
authors.forename: Thahira Begum
authors.initials: TB
authors.lastname: S A Ravoof
authors.affiliation: Department of Chemistry, University of Malaya, Kuala Lumpur 50603, Malaysia. edward.tiekink@gmail.com.
authors.forename: Edward R T
authors.initials: ER
authors.lastname: Tiekink
authors.affiliation: Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, UPM Serdang 43400, Malaysia. abhi.veerakumarasivam@gmail.com.|Medical Genetics Laboratory, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, UPM Serdang 43400, Malaysia. abhi.veerakumarasivam@gmail.com.
authors.forename: Abhimanyu
authors.initials: A
authors.lastname: Veerakumarasivam
authors.affiliation: Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, UPM Serdang 43400, Malaysia. kacrouse@gmail.com.|Department of Chemistry, Cape Breton University, Sydney, NS B1P 6L2, Canada. kacrouse@gmail.com.
authors.forename: Karen Anne
authors.initials: KA
authors.lastname: Crouse
authors.affiliation: Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, UPM Serdang 43400, Malaysia. ibra@upm.edu.my.
authors.forename: Mohamed Ibrahim
authors.initials: MI
authors.lastname: Mohamed Tahir
authors.affiliation: Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, UPM Serdang 43400, Malaysia. haslina_ahmad@upm.edu.my.
authors.forename: Haslina
authors.initials: H
authors.lastname: Ahmad
mesh_terms: D001547:Benzaldehydes / Q000737:chemistry; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D056831:Coordination Complexes / Q000138:chemical synthesis* / Q000737:chemistry / Q000633:toxicity; D003300:Copper / Q000737:chemistry; D018360:Crystallography, X-Ray; D004247:DNA / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D006860:Hydrogen Bonding; D008024:Ligands; D061986:MCF-7 Cells; D008968:Molecular Conformation; D009532:Nickel / Q000737:chemistry; D009584:Nitrogen / Q000737:chemistry*; D012545:Schiff Bases / Q000737:chemistry; D013455:Sulfur / Q000737:chemistry*; D028561:Transition Elements / Q000737:chemistry*; D015032:Zinc / Q000737:chemistry
chemical_list: D001547:Benzaldehydes; D056831:Coordination Complexes; D008024:Ligands; D012545:Schiff Bases; D028561:Transition Elements; D013455:Sulfur; D003300:Copper; D009532:Nickel; C520102:3-methoxybenzaldehyde; D004247:DNA; D015032:Zinc; D009584:Nitrogen
keywords: DNA binding; bidentate NS ligands; crystal structure analysis; cytotoxic activity; hydrogen bonding