title: In vitro study of DNA interaction with a water-soluble dinitrogen schiff base.
abstract: The present study investigates the binding interaction between a water-soluble Schiff base, N,N'-bis{5-[(triphenylphosphonium chloride)-methyl]salicylidine}-o-phenylenediamine (SF), and calf thymus DNA (CT-DNA) using emission, absorption, circular dichroism, and viscosity studies. In fluorimetric studies, the dynamic enhancement constant (K(D)) and bimolecular enhancement constant (K(B)) were calculated at different temperatures and demonstrated that fluorescence enhancement is not initiated by a dynamic process, but instead by a static process that involves complex DNA formation in the ground state. Further, the enthalpy and entropy of the reaction between SF and CT-DNA showed that the reaction is exothermic and enthalpy-favored (DeltaH = -153.51 kJ mol(-1); DeltaS = -427.67 J mol(-1) K). In addition, detectable changes in the circular dichroism spectrum of CT-DNA in the presence of SF indicated deep conformational changes in the DNA double helix following interaction with SF. Further, the Schiff base at different concentrations is able to perform cleavage of pUC18 plasmid DNA. All these results prove that SF interacts with CT-DNA via an intercalative mode of binding.
authors.affiliation: Department of Chemistry, Faculty of Science, Razi University, Kermanshah, Iran. nahidshahabadi@yahoo.com
authors.forename: Nahid
authors.initials: N
authors.lastname: Shahabadi
authors.forename: Soheila
authors.initials: S
authors.lastname: Kashanian
authors.forename: Farivash
authors.initials: F
authors.lastname: Darabi
mesh_terms: D004247:DNA / Q000737:chemistry* / Q000378:metabolism*; D005453:Fluorescence; D009943:Organophosphorus Compounds / Q000737:chemistry / Q000378:metabolism*; D012545:Schiff Bases / Q000737:chemistry / Q000378:metabolism*; D013696:Temperature
chemical_list: C544921:N,N'-bis(5-((triphenylphosphonium)methyl)salicylidine)-o-phenylenediamine; D009943:Organophosphorus Compounds; D012545:Schiff Bases; D004247:DNA; C427203:calf thymus DNA