DNA-Binding and Photocleavage Behaviour of [Ru(bpy)2(MDPZ)]2+

2008 ◽  
Vol 61 (5) ◽  
pp. 376 ◽  
Author(s):  
Lifeng Tan ◽  
Hui Chao ◽  
Junjie Fei ◽  
Guojun Su ◽  
Sheng Zhang ◽  
...  

The new ligand MDPZ (MDPZ = 7,7′-methylenedioxyphenyldipyrido[3,2-a:2′,3′-c]-phenazine and its RuII complex [Ru(bpy)2(MDPZ)]2+ (phen = 1,10-phenanthroline) was synthesized and characterized by elemental analysis, mass spectrometry, and 1H NMR spectroscopy. The DNA-binding properties of [Ru(bpy)2(MDPZ)]2+ were investigated by different spectrophotometric methods and viscosity measurements. The results suggest that the complex binds to CT-DNA through intercalation, and can enantioselectively interact with CT-DNA. Although the [Ru(bpy)2(MDPZ)]2+ complex does not show the characteristics of a molecular ‘light switch’ for DNA, [Ru(phen)2(MDPZ)]2+ may serve as a sensitive luminescent probe for DNA. Also, when irradiated at 365 nm, the complex promotes the photocleavage of pBR 322 DNA.

2008 ◽  
Vol 61 (9) ◽  
pp. 725 ◽  
Author(s):  
Lifeng Tan ◽  
Sheng Zhang ◽  
Xiaohua Liu ◽  
Yue Xiao

The new ligand 2-(5-methyl-furan-2-yl)imidazo[4,5-f][1, 10]phenanthroline (MFIP) and its complexes [Ru(bpy)2(MFIP)]2+ 1 (bpy = 2,2′-bipyridine) and [Ru(phen)2(MFIP)]2+ 2 (phen = 1,10-phenanthroline) were synthesized and characterized by elemental analysis, mass spectrometry, and 1H NMR spectroscopy. The DNA binding properties of the two complexes were investigated by different spectrophotometric methods and viscosity measurements. The results suggest that both complexes bind to calf thymus DNA (CT-DNA) through intercalation, and both complexes can enantioselectively interact with CT-DNA. The Λ enantiomers of both complexes are slightly predominant for binding to CT-DNA over the Δ enantiomer. When irradiated at 400 nm, the two complexes promote the photocleavage of pBR322 DNA, and complex 2 cleaves DNA more effectively than complex 1 under comparable experimental conditions. Furthermore, mechanism studies reveal that singlet oxygen (1O2) plays a significant role in the photocleavage.


2012 ◽  
Vol 67 (8) ◽  
pp. 819-826 ◽  
Author(s):  
Huilu Wu ◽  
Ying Bai ◽  
Jingkun Yuan ◽  
Hua Wang ◽  
Guolong Pan ◽  
...  

A ternary cationic Mn(II) complex with the tripodal ligand tris(2-(N-methyl) benzimidazylmethyl)amine (Mentb), salicylate and DMF as ligands and nitrate as counterion, [Mn(Mentb)(salicylate)DMF](NO3), was synthesized and characterized by physico-chemical and spectroscopic methods. The crystal structure of the Mn(II) complex has been determined by single-crystal X-ray diffraction and revealed that the central Mn(II) atom is seven-coordinated. The DNA-binding properties of the Mn(II) complex were investigated by spectrophotometric methods and viscosity measurements, and the results suggest that the Mn(II) complex binds to DNA via an intercalation binding mode. Additionally, the complex exhibited potential hydroxyl radical scavenge properties in in vitro studies


2013 ◽  
Vol 68 (3) ◽  
pp. 257-266 ◽  
Author(s):  
Guolong Pan ◽  
Yuchen Bai ◽  
Hua Wang ◽  
Jin Kong ◽  
Furong Shi ◽  
...  

A Schiff base ligand bis(N-salicylidene)-3-oxapentane-1,5-diamine (H2L) and its lutetium(III) complex, with composition Lu2(L)2(NO3)2, were synthesized and characterized by physico-chemical and spectroscopic methods. The crystal structure of the Lu(III) complex has been determined by single-crystal X-ray diffraction. It reveals a centrosymmetric binuclear neutral entity where Lu(III) metal centers are bridged by two phenoxo oxygen atoms. The DNA-binding properties of the Lu(III) complex were investigated by spectrophotometric methods and viscosity measurements, and the results suggest that the Lu(III) complex binds to DNA via a groove binding mode. Additionally, the antioxidant activity of the Lu(III) complex was determined by the superoxide and hydroxyl radical scavenging methods in vitro, which indicate that it is a scavenger for OH· and O-· 2 radicals.


2016 ◽  
Vol 45 (11) ◽  
pp. 4633-4646 ◽  
Author(s):  
Dejan Lazić ◽  
Aleksandar Arsenijević ◽  
Ralph Puchta ◽  
Živadin D. Bugarčić ◽  
Ana Rilak

UV-Vis spectroscopy studies, viscosity measurements and competitive binding studies with EB have revealed the ability of the complexes to bind to CT DNA covalently through N7 of guanine residues and non-covalently through intercalation.


2004 ◽  
Vol 59 (3) ◽  
pp. 310-318 ◽  
Author(s):  
◽  
Karna Wijaya ◽  
Daryono H. Tjahjono ◽  
Naoki Yoshioka ◽  
Hidenari Inoue

An iron(II) mixed-ligand complex with 1,10-phenanthroline (phen) and dipyrido[3,2-a:2’,3’- c]phenazine (dppz), [Fe(phen)2(dppz)]2+, has been synthesized. The DNA-binding properties of the mixed-ligand complex have been studied in terms of equilibrium binding constant, thermodynamic parameter, thermal denaturation as well as Pfeiffer effect upon binding to DNA. The spectrophotometric titration of [Fe(phen)2(dppz)]2+ with calf thymus DNA (ct-DNA) has shown that the iron(II) mixed-ligand complex binds effectively to ct-DNA in an intercalation mode as indicated by remarkable hypochromicity (ca. 36%) and moderate bathochromic shift (8 nm) of the absorption spectra. This intercalative mode is supported by a significant increase (Δ Tm = 21 °C) in the melting temperature (Tm) of ct-DNA at R([complex]/[ct-DNA]) = 1.5. The binding of [Fe(phen)2(dppz)]2+ to ct-DNA is entropically driven as characterized by a positive enthalpy change and a large negative TΔ S term. An intense CD signal in the UV and visible region develops upon addition of ct-DNA to the racemate solution of [Fe(phen)2(dppz)]2+. This has revealed that a shift in diastereomeric inversion equilibrium takes place in the solution to yield an excess of one enantiomer of the DNA-iron(II) complex (Pfeiffer effect). The striking resemblance of the CD spectral profiles to those of the corresponding Δ -enantiomer indicates that Δ -[Fe(phen)2(dppz)]2+ is preferentially bound to ct-DNA


2018 ◽  
Vol 205 ◽  
pp. 8-14 ◽  
Author(s):  
Helio G. Bonacorso ◽  
Tainara P. Calheiro ◽  
Bernardo A. Iglesias ◽  
Carolina Hahn da Silveira ◽  
Eufrânio N. da Silva Júnior ◽  
...  

2021 ◽  
Vol 17 ◽  
pp. 991-1000
Author(s):  
Peter Jonas Wickhorst ◽  
Mathilda Blachnik ◽  
Denisa Lagumdzija ◽  
Heiko Ihmels

Eleven novel 10-O-aryl-substituted berberrubine and berberine derivatives were synthesized by the Cu2+-catalyzed Chan–Evans–Lam coupling of berberrubine with arylboronic acids and subsequent 9-O-methylation. The reaction is likely introduced by the Cu2+-induced demethylation of berberrubine and subsequent arylation of the resulting 10-oxyanion functionality. Thus, this synthetic route represents the first successful Cu-mediated coupling reaction of berberine substrates. The DNA-binding properties of the 10-O-arylberberine derivatives with duplex and quadruplex DNA were studied by thermal DNA denaturation experiments, spectrometric titrations as well as CD and LD spectroscopy. Fluorimetric DNA melting analysis with different types of quadruplex DNA revealed a moderate stabilization of the telomeric quadruplex-forming oligonucleotide sequence G3(TTAG3)3. The derivatives showed a moderate affinity towards quadruplex DNA (K b = 5–9 × 105 M−1) and ct DNA (K b = 3–5 × 104 M−1) and exhibited a fluorescence light-up effect upon complexation to both DNA forms, with slightly higher intensity in the presence of the quadruplex DNA. Furthermore, the CD- and LD-spectroscopic studies revealed that the title compounds intercalate into ct DNA and bind to G4-DNA by terminal stacking.


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