title: Cobalt(II), Nickel(II) and Copper(II) complexes of a tetradentate Schiff base as photosensitizers: Quantum yield of 1O2 generation and its promising role in anti-tumor activity.
abstract: In the present investigation, a Schiff base N'1,N'3-bis[(E)-(5-bromo-2-hydroxyphenyl)methylidene]benzene-1,3-dicarbohydrazide and its metal complexes have been synthesized and characterized. The DNA-binding studies were performed using absorption spectroscopy, emission spectra, viscosity measurements and thermal denatuaration studies. The experimental evidence indicated that, the Co(II), Ni(II) and Cu(II) complexes interact with calf thymus DNA through intercalation with an intrinsic binding constant Kb of 2.6×10(4) M(-1), 5.7×10(4) M(-1) and 4.5×10(4) M(-1), respectively and they exhibited potent photodamage abilities on pUC19 DNA, through singlet oxygen generation with quantum yields of 0.32, 0.27 and 0.30 respectively. The cytotoxic activity of the complexes resulted that they act as a potent photosensitizers for photochemical reactions.
authors.affiliation: Department of Studies and Research in Industrial Chemistry, Kuvempu University, Shankaraghatta 577 451, Shimoga, India.
authors.forename: S M
authors.initials: SM
authors.lastname: Pradeepa
authors.forename: H S
authors.initials: HS
authors.lastname: Bhojya Naik
authors.forename: B
authors.initials: B
authors.lastname: Vinay Kumar
authors.forename: K
authors.initials: K
authors.lastname: Indira Priyadarsini
authors.forename: Atanu
authors.initials: A
authors.lastname: Barik
authors.forename: T R
authors.initials: TR
authors.lastname: Ravikumar Naik
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000737:chemistry / Q000494:pharmacology*; D002417:Cattle; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D003035:Cobalt / Q000737:chemistry / Q000494:pharmacology*; D056831:Coordination Complexes / Q000737:chemistry / Q000494:pharmacology*; D003300:Copper / Q000737:chemistry / Q000494:pharmacology*; D004247:DNA / Q000378:metabolism; D006801:Humans; D008175:Lung Neoplasms / Q000188:drug therapy; D009532:Nickel / Q000737:chemistry / Q000494:pharmacology*; D017319:Photosensitizing Agents / Q000737:chemistry / Q000494:pharmacology*; D012545:Schiff Bases / Q000737:chemistry / Q000494:pharmacology; D026082:Singlet Oxygen / Q000378:metabolism
chemical_list: D000970:Antineoplastic Agents; D056831:Coordination Complexes; D017319:Photosensitizing Agents; D012545:Schiff Bases; D026082:Singlet Oxygen; D003035:Cobalt; D003300:Copper; D009532:Nickel; D004247:DNA; C427203:calf thymus DNA