title: New palladium(II) and platinum(II) complexes with the model nucleobase 1-methylcytosine: antitumor activity and interactions with DNA.
abstract: Palladium and platinum complexes with the model nucleobase 1-methylcytosine (1-Mecyt) of the types [Pd(N-N)(C6F5)(1-Mecyt)]ClO4 [N-N = bis(3,5-dimethylpyrazol-1-yl)methane (bpzm), bis(pyrazol-1-yl)methane (bpzm), N,N,N',N'-tetramethylethylenediamine (tmeda), or 2,2'-bipyridine (bpy)] and [M(dmba)(L')(1-Mecyt)]ClO4 [dmba = N,C-chelating 2-(dimethylaminomethyl)phenyl; L' = PPh(3) (M = Pd or Pt), DMSO (M = Pt)] have been obtained. Palladium and platinum complexes of the types cis-[M(C6F5)2(1-Mecyt)2] (M = Pd or Pt) and cis-[Pd(L')(C6F5)(1-Mecyt)2]ClO4 (L' = PPh(3) or t-BuNC) have also been prepared. The crystal structures of [Pd(bpzm)(C6F5)(1-Mecyt)]ClO4, [Pt(dmba)(DMSO)(1-Mecyt)]ClO4, cis-[Pd(C6F5)2(1-Mecyt)2], and cis-[Pd(t-BuNC)(C6F5)(1-Mecyt)2]ClO4 have been established by X-ray diffraction. There is extensive hydrogen bonding (N-H...O, C-H...F or C-H...O) in all the compounds. There are also intermolecular pi-pi interactions between pyrimidine rings of adjacent chains in [Pd(C6F5)2(1-Mecyt)2]. DNA adduct formation of the new complexes synthesized was followed by circular dichroism and electrophoretic mobility. Atomic force microscopy images of the modifications caused by the complexes on plasmid DNA pBR322 were also obtained. Values of IC(50) were also calculated for the new complexes against the tumor cell line HL-60. At a short incubation time (24 h) almost all new complexes were more active than cisplatin.
authors.affiliation: Departamento de Química Inorgánica, Facultad de Química, Universidad de Murcia, 30071 Murcia, Spain. jruiz@um.es
authors.forename: José
authors.initials: J
authors.lastname: Ruiz
authors.forename: Natalia
authors.initials: N
authors.lastname: Cutillas
authors.forename: Consuelo
authors.initials: C
authors.lastname: Vicente
authors.forename: María Dolores
authors.initials: MD
authors.lastname: Villa
authors.forename: Gregorio
authors.initials: G
authors.lastname: López
authors.forename: Julia
authors.initials: J
authors.lastname: Lorenzo
authors.forename: Francesc X
authors.initials: FX
authors.lastname: Avilés
authors.forename: Virtudes
authors.initials: V
authors.lastname: Moreno
authors.forename: Delia
authors.initials: D
authors.lastname: Bautista
mesh_terms: D000970:Antineoplastic Agents / Q000737:chemistry*; D018360:Crystallography, X-Ray; D003596:Cytosine / Q000031:analogs & derivatives*; D004247:DNA / Q000737:chemistry*; D018736:DNA Adducts; D009682:Magnetic Resonance Spectroscopy; D018625:Microscopy, Atomic Force; D008968:Molecular Conformation; D010165:Palladium / Q000737:chemistry*; D010984:Platinum / Q000737:chemistry*; D017671:Platinum Compounds / Q000737:chemistry*
chemical_list: D000970:Antineoplastic Agents; D018736:DNA Adducts; D017671:Platinum Compounds; C031532:1-methylcytosine; D010984:Platinum; D010165:Palladium; D003596:Cytosine; D004247:DNA