title: DNA binding, photoactivated DNA cleavage and cytotoxic activity of Cu(II) and Co(II) based Schiff-base azo photosensitizers.
abstract: A new class of Cu(II) and Co(II) complexes of azo-containing Schiff base of the type [Cu(L1)2] and [Co(L1)2], where L1=4-[(E)-{2-hydroxy-3-[(E)-(4-bromophenyl)diazenyl]benzylidene}amino]benzoic acid have been synthesized and characterized. Extension of conjugation and the presence of free carboxylic acid group of the ligand L1 increased the wavelength of the complexes from visible region to the near IR region (620-850 nm). The Cu(II) and Co(II) complexes interacted with CT-DNA via intercalative mode with the respective Kb value of 3.2×10(4) M(-1) and 2.9×10(4) M(-1) and acted as proficient photocleavers of SC pUC19 DNA in UV-A light, forming (1)O2 as the reactive oxygen species with the quantum yield of 0.38 and 0.36, respectively. Furthermore, the Cu(II) and Co(II) complexes showed photocytotoxicity toward two selected tumor cell lines MCF-7 and A549 by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide (MTT) method, and the Cu(II) complex exhibits higher photocytotoxicity than Co(II) complex against each of the selected cell lines, this result is identical with their DNA binding ability order.
authors: Department of Studies and Research in Industrial Chemistry, Kuvempu University, Shankaraghatta 577 451, Shimoga, India.
authors: S M
authors: SM
authors: Pradeepa
authors: Department of Studies and Research in Industrial Chemistry, Kuvempu University, Shankaraghatta 577 451, Shimoga, India. Electronic address: hsb_naik@rediffmail.com.
authors: H S
authors: HS
authors: Bhojya Naik
authors: Department of Chemistry, R N Shetty Institute of Technology, Uttarahalli Road, Channasandra, Bengaluru 560 098, India.
authors: B
authors: B
authors: Vinay Kumar
authors: Radiation Chemistry Section, Radiation and Photochemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085, India.
authors: K
authors: K
authors: Indira Priyadarsini
authors: Radiation Chemistry Section, Radiation and Photochemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085, India.
authors: Atanu
authors: A
authors: Barik
authors: Department of Studies and Research in Industrial Chemistry, Sir. M. V. Govt. Science College, Bommanakatte, Bhadravathi 577 302, India.
authors: M C
authors: MC
authors: Prabhakara
mesh_terms: D000818:Animals; D002417:Cattle; D003035:Cobalt / Q000494:pharmacology*; D003300:Copper / Q000494:pharmacology*; D004247:DNA / Q000378:metabolism*; D053837:DNA Cleavage / Q000187:drug effects*; D004583:Electrons; D004587:Electrophoresis, Agar Gel; D006801:Humans; D020128:Inhibitory Concentration 50; D061986:MCF-7 Cells; D013058:Mass Spectrometry; D009691:Nucleic Acid Denaturation / Q000187:drug effects; D017319:Photosensitizing Agents / Q000494:pharmacology*; D066244:Proton Magnetic Resonance Spectroscopy; D012545:Schiff Bases / Q000494:pharmacology*; D026082:Singlet Oxygen / Q000737:chemistry; D012995:Solubility; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet; D014783:Viscosity
chemical_list: D017319:Photosensitizing Agents; D012545:Schiff Bases; D026082:Singlet Oxygen; D003035:Cobalt; D003300:Copper; D004247:DNA; C427203:calf thymus DNA
keywords: DNA; Photocleavage; Photocytotoxicity; Photosensitizer; Schiff base