DNA Photocleavage by a Supramolecular Ru(II)−Viologen Complex

Abstract

A novel Ru(II) complex possessing two sequentially linked viologen units, Ru-V(1)-V(2)(6+), was synthesized and characterized. Upon excitation of the Ru(II) unit (lambda(exc) = 532 nm, fwhm approximately 10 ns), a long-lived charge-separated (CS) state is observed (tau = 1.7 micros) by transient absorption spectroscopy. Unlike Ru(bpy)(3)(2+), which cleaves DNA upon photolysis through the formation of reactive oxygen species, such as (1)O(2) and O(2)(-), the photocleavage of plasmid DNA by Ru-V(1)-V(2)(6+) is observed both in air and under N(2) atmosphere (lambda(irr) > 395 nm).

DNA Interactions Mediated by Cyclopentadienidoruthenium(II) Complexes Containing Water‐Soluble Phosphanes

“…The reaction was performed in the dark even though no photochemical activation of the present ruthenium complexes has been observed, in contrast to other ruthenium complexes. [27,28] Delay of SC DNA was observed for complexes 1, 2, 3 and 7. In addition, a modest increase in the amount of OC DNA was observed, relative to untreated DNA, which indicates that some DNA cleavage may also occur.…”

Bifunctional transition metal complexes as nucleic acid photoprobes and photoreagents

“…Turro and co-workers [78] recently designed an interesting artificial photonuclease based on a chromophorequencher supramolecular assembly, 9. In this triad system, a [Ru(bpy) 3 ] 2+ -like moiety is covalently linked to an electron acceptor chain composed of two viologen units.…”

DNA interaction with dipolar ruthenium(II) ammine complexes containing 4,4′-bipyridinium as photochemotherapeutic agents

“…ROS put oxidative stress on cells, causing cell death. Since malignant cancers are often hypoxic, O 2 -independent PDT agents must be also sought [22][23][24][25][26][27][28][29][30][31][32][33]. The photoactivated chemotherapy (PACT), which provides the opportunity for the activation under aerobic and anaerobic conditions, offers both temporal and spatial control over drug activation and has remarkable potential for the treatment of cancer [34].…”