title: Interactions of Some Divalent Metal Ions with Thymine and Uracil Thiosemicarbazide Derivatives.
abstract: The study of interactions between metal ions and nucleobases, nucleosides, nucleotides, or nucleic acids has become an active research area in chemical, biological, and therapeutic fields. In this respect, the coordination behavior of nucleobase derivatives to transition metals was studied in order to get a better understanding about DNA-metal interactions in in vitro and in vivo systems. Two nucleobase derivatives, 3-benzoyl-1-[3-(thymine-1-yl)propamido]thiourea and 3-benzoyl-1-[3-(uracil-1-yl)propamido]thiourea, were synthesized and their dissociation constants were determined at different temperatures and 0.3 ionic strength. Potentiometric studies were carried out on the interaction of the derivatives towards some divalent metals in 50% v/v ethanol-water containing 0.3 mol.dm(-3) KCl, at five different temperatures. The formation constants of the metal complexes for both ligands follow the order: Cu(2+) > Ni(2+) > Co(2+) > Zn(2+) > Pb(2+) > Cd(2+) > Mn(2+). The thermodynamic parameters were estimated; the complexation process has been found to be spontaneous, exothermic, and entropically favorable.
authors.affiliation: a Department of Chemistry, Faculty of Science , King Faisal University , Al-Ahsa , Saudi Arabia.
authors.forename: Hassan H
authors.initials: HH
authors.lastname: Hammud
authors.affiliation: b Department of Chemistry, Faculty of Science , Beirut Arab University , Debbieh , Lebanon.
authors.forename: Mohammad H
authors.initials: MH
authors.lastname: El-Dakdouki
authors.affiliation: b Department of Chemistry, Faculty of Science , Beirut Arab University , Debbieh , Lebanon.
authors.forename: Nada
authors.initials: N
authors.lastname: Sonji
authors.affiliation: b Department of Chemistry, Faculty of Science , Beirut Arab University , Debbieh , Lebanon.
authors.forename: Ghassan
authors.initials: G
authors.lastname: Sonji
authors.affiliation: c Department of Chemistry, Faculty of Arts and Sciences , American University of Beirut , Beirut , Lebanon.
authors.forename: Kamal H
authors.initials: KH
authors.lastname: Bouhadir
mesh_terms: D003035:Cobalt / Q000737:chemistry; D056831:Coordination Complexes / Q000138:chemical synthesis*; D003300:Copper / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D012663:Semicarbazides / Q000737:chemistry*; D013816:Thermodynamics; D013941:Thymine / Q000737:chemistry*; D014498:Uracil / Q000737:chemistry*
chemical_list: D056831:Coordination Complexes; D012663:Semicarbazides; D003035:Cobalt; D014498:Uracil; C005151:thiosemicarbazide; D003300:Copper; C018021:cobaltous chloride; D013941:Thymine; C029892:cupric chloride
keywords: Nucleic bases; dissociation constants; metal complexes; potentiometry; stability constants; thermodynamic parameters; thiourea derivatives