Synthesis, Characterization, DNA Binding Studies, Photocleavage, Cytotoxicity and Docking Studies of Ruthenium(II) Light Switch Complexes

Abstract

A new ligand 3-(1H-imidazo[4,5-f][1,10]phenanthrolin-2yl)phenylboronic acid and its (IPPBA) three ruthenium(II) complexes [Ru(phen)2(IPPBA)](ClO4)2 (1), [Ru(bpy)2(IPPBA)](ClO4)2 (2) and [Ru(dmb)2(IPPBA)](ClO4)2 (3) have been synthesized and characterized by elemental analysis, UV/VIS, IR, (1)H-NMR,(13)C-NMR and mass spectra. The binding behaviors of the three complexes to calf thymus DNA were investigated by absorption spectra, emission spectroscopy, viscosity measurements, thermal denaturation and photoactivated cleavage. The DNA-binding constants for complexes 1, 2 and 3 have been determined to be 7.9 × 10(5) M(-1), 6.7 × 10(5) M(-1) and 2.9 × 10(5) M(-1). The results suggest that these complexes bound to double-stranded DNA in an intercalation mode. Upon irradiation at 365 nm, three ruthenium complexes were found to promote the cleavage of plasmid pBR322 DNA from super coiled form І to nicked form ІІ. Further in the presence of Co(2+), the emission of DNA-Ru(ΙΙ) complexes can be quenched. And when EDTA was added, the emission was recovered. The experimental results show that all three complexes exhibited the "on-off-on" properties of molecular "light switch". The highest Cytotoxicity potential of the complex1 was observed on the Human alveolar adenocarcinoma (A549) cell line. Good agreement was generally found between the spectroscopic techniques and molecular docked model which provides further evidence of groove binding.

Synthesis, characterization, antimicrobial screening and DNA binding of novel silver(I)–thienylterpyridine and silver(I)–furylterpyridine complexes

“…Silver(I) complexes 1 – 6 were investigated for DNA binding properties via the hydrodynamic method. This method allows distinct, straightforward and unambiguous assessment of the nature of DNA binding by compounds . Compounds with intercalating properties tend to elongate the double helix of DNA as they try to fit between the base pairs.…”

A Promising Dna Groove Binder and Photocleaver Based on a Dinuclear Ruthenium(ii) Complex

“…The ruthenium complex has a dipositive charge in neutral aqueous solution, so it could be expected that the interaction between the ruthenium complex and DNA would be influenced by such factors as the presence of other cations or the ionic strength of the solution. [50] The sensitivity of the DNA binding constants of the ruthenium complexes to ionic strength is expected to decrease in the order of the binding modes, electrostatic > groove > intercalative, which could give insight into the DNA binding modes in quantitative manners. As the polyelectrolyte theories reported by Record et al are strictly applicable to salt concentrations of lower than 0.100 M, the salt concentrations of 0.025, 0.050, 0.075 and 0.100 M were selected in this study.…”

Design, synthesis, DNA-binding affinity, cytotoxicity, apoptosis, and cell cycle arrest of Ru(II) polypyridyl complexes

“…Until now our group has been synthesized some Ru(II) mixed polypyridyl complexes, which bind to DNA through an intercalative mode, promote cleavage of plasmid pBR322 DNA and were exhibited antitumor activity [27][28][29][30][31][32][33][34]. In this context, we have synthesized and characterized a new ligand CNPFIP and its three complexes [Ru(phen) 2 …”