Ambivalent intercalators for DNA: L-shaped platinum(II) complexes.
Novel platinum(II) square planar coordination complexes, in which two heteroaromatic ligands are held by the metal in an unusual L-shaped geometry orthogonal to each other, have been synthesized, and their interaction with DNA was investigated with absorption and linear dichroism spectroscopy. As a rule, the ligand that is coplanar with the coordination square of Pt is found to be oriented perpendicular relative to the DNA helix axis when bound, suggestive of its intercalation between the base pairs of DNA. However, when this coplanar ligand is replaced by two pyridines, the opposite ligand, orthogonal to the coordination square, is instead preferentially intercalated. This behavior shows that these new complexes do indeed show some properties of true ambintercalators, i.e., compounds that can bind by intercalation of either of two distinct aromatic moieties.
Cusumano
Matteo
M
Dipartimento di Chimica Inorganica, Chimica Analitica e Chimica Fisica, University of Messina, 98166 Messina, Italy.
Di Pietro
Maria Letizia
ML
Giannetto
Antonino
A
Nicolò
Francesco
F
Nordén
Bengt
B
Lincoln
Per
P
D004247:DNA / Q000737:chemistry*; D007202:Indicators and Reagents; D007364:Intercalating Agents / Q000138:chemical synthesis* / Q000737:chemistry*; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008968:Molecular Conformation; D015394:Molecular Structure; D009690:Nucleic Acid Conformation; D009944:Organoplatinum Compounds / Q000138:chemical synthesis* / Q000737:chemistry*
D007202:Indicators and Reagents; D007364:Intercalating Agents; D008024:Ligands; D009944:Organoplatinum Compounds; D004247:DNA; C427203:calf thymus DNA