title: Mixed ligand complexes of Cu(II)/Zn(II) ions containing (m-)/(p-) carboxylato phenyl azo pentane 2,4-dione and 2,2'-bipyridine/1,10 phenanthroline: Synthesis, characterization, DNA binding, nuclease and topoisomerase I inhibitory activity.
abstract: Metal complexes of type [Cu(L1H)2(bpy)] (1), [Zn(L1H)2(bpy)] (2), [Cu(L2H)2(bpy)] (3) and [Cu(L2H)2(Phen)] (4) (L1H2=3-[N'-(1-acetyl-2-oxo-propylidene)-hydrazino]-benzoic acid, L2H2=4-[N'-(1-acetyl-2-oxo-propylidene)-hydrazino]-benzoic acid, bpy=2,2'-bipyridine, Phen=1,10 phenanthroline) are synthesized and characterized using spectroscopic techniques (FT-IR, (1)H NMR, (13)C NMR, electronic absorption and emission) and elemental analysis data. The assembly of the complexes involving intramolecular H-bonding is displayed using corresponding crystal structure. Binding of the complexes separately with Calf Thymus DNA is monitored using UV-vis spectral titrations. The displacement of ethidium bromide (EB) bound to DNA by the complexes, in phosphate buffer solution (pH∼7.2) is monitored using fluorescence spectral titrations. Nuclease activity of the complexes follow the order 4>3>1>2. The gel electrophoretic mobility assay measurement in presence of minor groove binder 4',6-diamidino-2-phenylindole (DAPI), suggests that complexes preferably bind with the minor groove of DNA. Topoisomerase I inhibitory activity of the complexes 3 and 4 inhibit topoisomerase I activity with IC50 values of 112 and 87μM respectively.
authors.affiliation: Department of Chemistry, Faculty of Science, Banaras Hindu University, Varanasi, India.
authors.forename: Md Amin
authors.initials: MA
authors.lastname: Hasan
authors.affiliation: Department of Chemistry, Faculty of Science, Banaras Hindu University, Varanasi, India.
authors.forename: Niraj
authors.initials: N
authors.lastname: Kumari
authors.affiliation: Molecular and Human Genetics, Banaras Hindu University, Varanasi, India.
authors.forename: Kanhaiya
authors.initials: K
authors.lastname: Singh
authors.affiliation: Molecular and Human Genetics, Banaras Hindu University, Varanasi, India.
authors.forename: Kiran
authors.initials: K
authors.lastname: Singh
authors.affiliation: Department of Chemistry, Faculty of Science, Banaras Hindu University, Varanasi, India. Electronic address: lmishrabhu@yahoo.co.in.
authors.forename: Lallan
authors.initials: L
authors.lastname: Mishra
mesh_terms: D015082:2,2'-Dipyridyl / Q000737:chemistry / Q000494:pharmacology; D000818:Animals; D002417:Cattle; D056831:Coordination Complexes / Q000737:chemistry / Q000494:pharmacology*; D003300:Copper / Q000737:chemistry / Q000494:pharmacology*; D018360:Crystallography, X-Ray; D004247:DNA / Q000378:metabolism*; D004264:DNA Topoisomerases, Type I / Q000378:metabolism; D004926:Escherichia coli / Q000201:enzymology; D008958:Models, Molecular; D010420:Pentanes / Q000737:chemistry / Q000494:pharmacology; D010618:Phenanthrolines / Q000737:chemistry / Q000494:pharmacology*; D059004:Topoisomerase I Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D015032:Zinc / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D056831:Coordination Complexes; D010420:Pentanes; D010618:Phenanthrolines; D059004:Topoisomerase I Inhibitors; C033353:pentane; D015082:2,2'-Dipyridyl; D003300:Copper; D004247:DNA; C427203:calf thymus DNA; D004264:DNA Topoisomerases, Type I; D015032:Zinc; C025205:1,10-phenanthroline
keywords: Azodiketone; Cu(II)/Zn(II) complexes; Spectral titration; Topoisomerase I inhibitory activity; X-ray diffraction