title: Multiple Condensation Reactions Involving Pt(II) /Pd(II) -OH2 , Pt-NH3 , and Cytosine-NH2 Groups: New Twists in Cisplatin-Nucleobase Chemistry.
abstract: The coordination chemistry of the antitumor agent cisplatin and related complexes with DNA and its constituents, that is, the nucleobases, appears to be dominated by 1:1 and 1:2 adducts of the types cis-[Pta2 (nucleobase)X] and cis-[Pta2 (nucleobase)2 ] (a=NH3 or amine; a2 =diamine or diimine; X=Cl, OH or OH2 ). Here, we have studied the interactions of the putative 1:1 adducts cis-[Pta2 (1-MeC-N3)(OH2 )](2+) (with a=NH3 , a2 =2,2'-bpy (2,2'-bipyridine), 1-MeC=model nucleobase 1-methylcytosine) with additional cis-[Pt(NH3 )2 (OH2 )2 ](2+) or its kinetically superior analogues [Pd(en)(OH2 )2 ](2+) (en=ethylenediamine) and [Pd(2,2'-bpy)(OH2 )2 ](2+) . Depending upon the conditions applied different compounds of different nuclearity are formed. Without exception they represent condensation products of the components, containing μ-1-MeC-H , μ-OH(-) , as well as μ-NH2 (-) bridges. In the presence of Ag(+) ions, the isolated products in several cases display additionally Pt→Ag dative bonds. On the basis of the cytosine-containing structures established by X-ray crystallography, it is proposed that any of the feasible initial 1:1 nucleobase adducts of cisplatin could form dinuclear Pt complexes upon reaction with additional hydrolyzed cisplatin, thereby generating nucleobase adducts other than the presently established ones. Two findings appear to be of particular significance: First, hydrolyzed cisplatin can have a moderately accelerating effect on the formation of a secondary nucleobase product. Second, NH3 ligands of the cisplatin moiety can be converted into bridging amido ligands following condensation with the diaqua species of cisplatin.
authors: Fakultät Chemie und Chemische Biologie (CCB), Technische Universität Dortmund, Otto-Hahn-Str. 6, 44221, Dortmund, Germany.
authors: Lu
authors: L
authors: Yin-Bandur
authors: Departamento de Química Inorgánica, Instituto de Sintesis Química y Catálisis Homogénea (ISQCH), Universidad de Zaragoza-CSIC, 50009, Zaragoza, Spain. pablo.sanz@unizar.es.
authors: Pablo J
authors: http://orcid.org/0000-0002-8220-6031
authors: PJ
authors: Sanz Miguel
authors: Department da Química, Universitat Autónoma Barcelona, Bellaterra, 08193, Barcelona, Spain. luis@klingon.uab.es.
authors: Luis
authors: L
authors: Rodríguez-Santiago
authors: Department da Química, Universitat Autónoma Barcelona, Bellaterra, 08193, Barcelona, Spain.
authors: Mariona
authors: M
authors: Sodupe
authors: Fakultät Chemie und Chemische Biologie (CCB), Technische Universität Dortmund, Otto-Hahn-Str. 6, 44221, Dortmund, Germany.
authors: Melanie
authors: M
authors: Berghaus
authors: Fakultät Chemie und Chemische Biologie (CCB), Technische Universität Dortmund, Otto-Hahn-Str. 6, 44221, Dortmund, Germany. bernhard.lippert@tu-dortmund.de.
authors: Bernhard
authors: B
authors: Lippert
mesh_terms: D000588:Amines / Q000737:chemistry*; D000970:Antineoplastic Agents / Q000737:chemistry*; D002945:Cisplatin / Q000737:chemistry*; D056831:Coordination Complexes / Q000737:chemistry*; D003596:Cytosine / Q000031:analogs & derivatives / Q000737:chemistry*; D004247:DNA / Q000737:chemistry; D008024:Ligands; D015394:Molecular Structure; D010165:Palladium / Q000737:chemistry*; D010984:Platinum / Q000737:chemistry*
chemical_list: D000588:Amines; D000970:Antineoplastic Agents; D056831:Coordination Complexes; D008024:Ligands; C031532:1-methylcytosine; D010984:Platinum; D010165:Palladium; D003596:Cytosine; D004247:DNA; D002945:Cisplatin
keywords: condensation reactions; density functional calculations; nucleobases; platinum; μ-amido complex