title: DNA interaction of platinum(II) complexes with 1,10-phenanthroline and extended phenanthrolines.
abstract: The interaction with DNA of the platinum(II) square planar complexes [Pt(N-N)(py)(2)](2+) (N-N = 1,10-phenanthroline (phen), dipyrido[3,2-d:2',3'-f]quinoxaline (dpq), dipyrido[3,2-a:2',3'-c]phenazine (dppz), benzodipyrido[b:3,2-h:2'3'-f]phenazine (bdppz)) has been investigated by means of absorption, circular and linear dichroism spectroscopy, DNA melting, and viscosity. In the presence of excess [DNA] all the complexes intercalate to the double helix. For those with the most extended phenanthrolines the binding mode depends on the [DNA]/[complex] ratio (q); at low q values the substances bind externally to DNA probably self-aggregating along the double helix. When the DNA concentration is large enough, the aggregate breaks up and the complex intercalates within the nucleobases. The complexes self-aggregate, without added DNA, in the presence of a large salt concentration.
authors.affiliation: Dipartimento di Chimica Inorganica, Chimica Analitica e Chimica Fisica, University of Messina, Italy. cusumano@chem.unime.it
authors.forename: Matteo
authors.initials: M
authors.lastname: Cusumano
authors.forename: Maria Letizia
authors.initials: ML
authors.lastname: Di Pietro
authors.forename: Antonino
authors.initials: A
authors.lastname: Giannetto
mesh_terms: D004247:DNA / Q000737:chemistry*; D015394:Molecular Structure; D009944:Organoplatinum Compounds / Q000737:chemistry*; D010618:Phenanthrolines / Q000737:chemistry*; D010984:Platinum / Q000737:chemistry*
chemical_list: D009944:Organoplatinum Compounds; D010618:Phenanthrolines; D010984:Platinum; D004247:DNA; C025205:1,10-phenanthroline