1539-42-0Relevant articles and documents
Polypyridyl-Based Copper Phenanthrene Complexes: Combining Stability with Enhanced DNA Recognition
Fantoni, Nicoló Zuin,Molphy, Zara,O'Carroll, Sinéad,Menounou, Georgia,Mitrikas, George,Krokidis, Marios G.,Chatgilialoglu, Chryssostomos,Colleran, John,Banasiak, Anna,Clynes, Martin,Roche, Sandra,Kelly, Suainibhe,McKee, Vickie,Kellett, Andrew
, p. 971 - 983 (2021)
We report a series of copper(II) artificial metallo-nucleases (AMNs) and demonstrate their DNA damaging properties and in-vitro cytotoxicity against human-derived pancreatic cancer cells. The compounds combine a tris-chelating polypyridyl ligand, di-(2-pycolyl)amine (DPA), and a DNA intercalating phenanthrene unit. Their general formula is Cu-DPA-N,N' (where N,N'=1,10-phenanthroline (Phen), dipyridoquinoxaline (DPQ) or dipyridophenazine (DPPZ)). Characterisation was achieved by X-ray crystallography and continuous-wave EPR (cw-EPR), hyperfine sublevel correlation (HYSCORE) and Davies electron-nuclear double resonance (ENDOR) spectroscopies. The presence of the DPA ligand enhances solution stability and facilitates enhanced DNA recognition with apparent binding constants (Kapp) rising from 105 to 107 m?1 with increasing extent of planar phenanthrene. Cu-DPA-DPPZ, the complex with greatest DNA binding and intercalation effects, recognises the minor groove of guanine–cytosine (G-C) rich sequences. Oxidative DNA damage also occurs in the minor groove and can be inhibited by superoxide and hydroxyl radical trapping agents. The complexes, particularly Cu-DPA-DPPZ, display promising anticancer activity against human pancreatic tumour cells with in-vitro results surpassing the clinical platinum(II) drug oxaliplatin.
Effects of the Ligand Structure of Cu(II) Complexes on Oxidative DNA Cleavage
Han, Ji Hoon,Kim, Ji Hoon,Jung, Maeng-Joon,Kim, Seog K.,Jang, Yoon Jung
, p. 1327 - 1335 (2021)
Cu complexes were synthesized by substituting the hydrogen of the amine group of basic ligand 2,2′-dipicoylamine (dpca) (complex 2) with CH3CO (complex 1), phenyl (complex 3), and methyl (complex 4), respectively, and their DNA cleavage activity was investigated using linear dichroism (LD) and electrophoresis. The DNA cleavage efficiencies of Cu complexes 3 and 4 with phenyl and methyl, which are electron-donating functional groups, turned out to be the highest, and LD magnitudes rapidly decreased at 260 nm. In particular, Cu complex 3 showed a rapid LD magnitude reduction to 63% of the total for 90 min, and to 50% of the total at 12 min. DNA cleavage efficiencies were high in the order of phenyl > methyl > HCH3CO, and the highest DNA cleavage efficiency was observed in the presence of electron-donating groups. The electrophoresis results are also consistent with the changes in LD spectra over time. The Cu complexes (1–4) were found to cleave DNA through oxidative pathways, and the major reaction oxygen species involved in DNA cleavage were the superoxide radical (·O2?), singlet oxygen (1O2), and hydroxyl radical (·OH).
Understanding the Origin of One- or Two-Step Valence Tautomeric Transitions in Bis(dioxolene)-Bridged Dinuclear Cobalt Complexes
Boskovic, Colette,Gable, Robert W.,Gransbury, Gemma K.,Hay, Moya A.,Janetzki, Jett T.,Livesay, Brooke N.,Shores, Matthew P.,Starikova, Alyona
, p. 10692 - 10704 (2020)
Valence tautomerism (VT) involves a reversible stimulated intramolecular electron transfer between a redox-active ligand and redox-active metal. Bis(dioxolene)-bridged dinuclear cobalt compounds provide an avenue toward controlled two-step VT interconversions of the form {CoIII-cat-cat-CoIII} ? {CoIII-cat-SQ-CoII}?{CoII-SQ-SQ-CoII} (cat2- = catecholate, SQ·- = semiquinonate). Design flexibility for dinuclear VT complexes confers an advantage over two-step spin crossover complexes for future applications in devices or materials. The four dinuclear cobalt complexes in this study are bridged by deprotonated 3,3,3′,3′-tetramethyl-1,1′-spirobi(indan)-5,5′,6,6′-tetraol (spiroH4) or 3,3,3′,3′-tetramethyl-1,1′-spirobi(indan)-4,4′,7,7′-tetrabromo-5,5′,6,6′-tetraol (Br4spiroH4) with Mentpa ancillary ligands (tpa = tris(2-pyridylmethyl)amine, n = 0-3 corresponds to methylation of the 6-position of the pyridine rings). Complementary structural, magnetic, spectroscopic, and density functional theory (DFT) computational studies reveal different electronic structures and VT behavior for the four cobalt complexes; one-step one-electron partial VT, two-step VT, incomplete VT, and temperature-invariant {CoIII-cat-cat-CoIII} states are observed. Electrochemistry, DFT calculations, and the study of a mixed-valence {ZnII-cat-SQ-ZnII} analog have allowed elucidation of thermodynamic parameters governing the one- and two-step VT behavior. The VT transition profile is rationalized by (1) the degree of electronic communication within the bis(dioxolene) ligand and (2) the matching of cobalt and dioxolene redox potentials. This work establishes a clear path to the next generation of two-step VT complexes through incorporation of mixed-valence class II and class II-III bis(dioxolene) bridging ligands with sufficiently weak intramolecular coupling.
CO2 fixation by dicopper(ii) complexes in hypodentate framework of N8O2
Ho, Yi-Hsueh,Chang, Mu-Chieh,Yu, Kuo-Hsuan,Liu, Yi-Hung,Wang, Yu,Cheng, Yuan-Chung,Chen, Jwu-Ting
, p. 6287 - 6290 (2014)
A new ligand with N8O2 donors containing three potential metal-binding sites (H2L) and its tricopper(ii) complex 1 are synthesized. The tricopper species is found to be formed from a hypodentate dicopper(ii) complex 2 in basic solutions. Complex 2 may be isolated from the reaction of H2L with a copper source under acidic conditions. Complex 2 can undergo CO2-abstraction to yield an octacopper(ii) complex 3. The single crystal structures of complexes 2 and 3 are characterized by X-ray crystallography. This journal is the Partner Organisations 2014.
Development of Gene-Targeted Polypyridyl Triplex-Forming Oligonucleotide Hybrids
Zuin Fantoni, Nicolò,McGorman, Bríonna,Molphy, Zara,Singleton, Daniel,Walsh, Sarah,El-Sagheer, Afaf H.,McKee, Vickie,Brown, Tom,Kellett, Andrew
, p. 3563 - 3574 (2020)
In the field of nucleic acid therapy there is major interest in the development of libraries of DNA-reactive small molecules which are tethered to vectors that recognize and bind specific genes. This approach mimics enzymatic gene editors, such as ZFNs, TALENs and CRISPR-Cas, but overcomes the limitations imposed by the delivery of a large protein endonuclease which is required for DNA cleavage. Here, we introduce a chemistry-based DNA-cleavage system comprising an artificial metallo-nuclease (AMN) that oxidatively cuts DNA, and a triplex-forming oligonucleotide (TFO) that sequence-specifically recognises duplex DNA. The AMN-TFO hybrids coordinate CuII ions to form chimeric catalytic complexes that are programmable – based on the TFO sequence employed – to bind and cut specific DNA sequences. Use of the alkyne-azide cycloaddition click reaction allows scalable and high-throughput generation of hybrid libraries that can be tuned for specific reactivity and gene-of-interest knockout. As a first approach, we demonstrate targeted cleavage of purine-rich sequences, optimisation of the hybrid system to enhance stability, and discrimination between target and off-target sequences. Our results highlight the potential of this approach where the cutting unit, which mimics the endonuclease cleavage machinery, is directly bound to a TFO guide by click chemistry.
A novel ditopic ligand derived from 8-hydroxyquinoline: Synthesis, characterisation, and its coordination chemistry with selected metal ions
Xie, Xiang,Jiang, Xiujuan,Liu, Jian,Ren, Xingye,Wang, Hongming,Liu, Xiaoming
, p. 132 - 136 (2012)
A novel multidentate ligand, 5-(bis(pyridin-2-ylmethyl)amino)quinolin-8-ol (HL) was synthesised and characterised. Its coordination modes with a variety of metal ions (Mg2+, Co2+, Cu2+, Zn2+, and Hg2+) were investigated using UV-Vis spectroscopic titration. Among the examined metal ions, coordination ratios (M2+: HL) between the metal ion and the ligand at 1:2, 1:1, and 3:2 were observed due to the ditopic nature of the ligand. In acetonitrile, Mg2+ showed relatively strong fluorescent response upon binding to the ligand among the examined metal ions, Li+, K+, Mg2+, Ca2+, Al 3+, Cu2+, Fe3+, Cr3+, Zn 2+, Co2+, Ni2+, and Hg2+.
Towards hydroperoxovanadium complexes: The X-ray crystal structure of a peroxovanadium(v) complex containing a V(O2)(RCO2H)(H2O)2 cluster with hydrogen bond inter-linkages
Casny,Rehder
, p. 921 - 922 (2001)
The molecular structure of the oxo-peroxovanadium complex [VO(O2)(bpaH)]ClO4·2H20, containing the new ligand N,N-bis(2-pyridylmethyl)-β-alanine (bpaH) reveals tight binding of the carboxylic acid function to the vanadium centre through its doubly bonded oxygen; the carboxylic acid proton mediates hydrogen bonding interactions comprising the peroxo group and the two waters of crystallisation, thus providing the basis for the potential formation of a hydroperoxo species.
Zn(II)-DPA Coordinative fluorescent probe for enhancing G4 DNA binding
Bai, Yi-Tong,Gao, Juan-Juan,Lang, Xue-Xian,Li, Hong-Yao,Wang, Hai-Jiao,Wang, Ming-Qi,Yu, Quan-Qi
, (2021)
Novel dipicolylamino functionalized styryl-carbazole derivative (YCJ) was designed and synthesized. This derivative in combination with Zn(II) has exhibited large fluorescence intensity enhancement and prominent red-shift in absorption spectra with G4 DNA. Systematical analysis indicats that YCJ-Zn(II) complex shows much higher binding affinity and spectral response to G4 DNA than our previously reported styryl-carbazole scaffold (E1) due to the incorporationc of a Zn(II)-DPA moiety which could decrease the carbazole core electron density and consequently enhance the ability to display π-π stacking interaction with G4 DNA. Spectroscopic and molecular docking studies have unraveled YCJ-Zn(II) complex can stack both 3′ and 5′-ends and an associated with partial loop/groove interactions. The application of this Zn(II) complex as a fluorescent agent for living cell imaging was also demonstrated. The conjugation of the Zn-DPA moiety results in good cell permeability, endogenous DNA labeling, which is suitable for monitoring of nucleus activities.
Photocatalytic degradation of dyes by mononuclear copper(II) complexes from bis-(2-pyridylmethyl)amine NNN-derivative ligands
Carvalho, Nakédia M. F.,Carvalho, Samira S. F.,Lima, Juliana F.,Rodrigues, Ana Carolina C.
, (2020)
Photocatalytic degradation of organic pollutant dyes under ultraviolet radiation has emerged as an efficient wastewater treatment. This work describes the application of four mononuclear copper(II) complexes coordinated to NNN ligands: bis-(2-pyridylmethyl)amine (BMPA), N-methylpropanoate-N,N-bis-(2-pyridylmethyl)amine (MPBMPA), N-propanoate-N,N-bis-(2-pyridylmethyl)amine (PBMPA) and N-propanamide-N,N-bis-(2-pyridylmethyl)amine (PABMPA); in the photocatalytic degradation of different dyes: methyl orange (MO), methylene blue (MB), crystal violet (CV), Congo red (CR) and Rhodamine B (RhB). The reactions were carried out under a UV lamp of 250 W, where 100percent of degradation was achieved in 90 min for all complexes using hydrogen peroxide as oxidant. Kinetic experiments were carried out to investigate the photodegradation of the dyes under a UV lamp of 24 W. The reactions followed a zero-order model in relation to the dye, showing that its concentration did not play a significant role in the photocatalysis. The reaction order in relation to hydrogen peroxide varied from 0 to 0.8, from low to high concentrations of oxidant. The light intensity and the intrinsic catalytic activity of the complexes are the most important features for the dye photodegradation pathway.
Synthesis and properties of a heterobimetallic iron-manganese complex and its comparison with homobimetallic analogues
Bedin, Michele,Agarwala, Hemlata,Marx, Jennifer,Schünemann, Volker,Ott, Sascha,Thapper, Anders
, p. 254 - 260 (2019)
Heterobimetallic cofactors containing one manganese and one iron ion have recently been found within the di-metal carboxylate protein family. Herein we report the synthesis and characterization of three binuclear metal complexes with Fe-Fe, Mn-Mn, and Fe-Mn metal composition. All three complexes use the same ligand framework, the BPMP ligand (HBPMP = 2,6-bis[(bis (-2-pyridylmethyl)amine) methyl]-4-methylphenol)) with two additional acetate ligands bridging the two metals. In terms of stability towards metal exchange, the Fe-Mn is more stable than the Mn-Mn complex but less stable than the Fe-Fe complex. Cyclic voltammetry shows that the Fe-Mn complex behaves markedly different than the homobimetallic complexes. The Fe-Mn complex also shows higher reactivity with O2 than both the Fe-Fe and the Mn-Mn counterparts.
