scholarly journals Synthesis, characterization and DNA cleavage activity of nickel(II) adducts with aromatic heterocyclic bases

2010 ◽  
Vol 75 (1) ◽  
pp. 61-74 ◽  
Author(s):  
Surendra Babu ◽  
Pitchika Krishna ◽  
Hussain Reddy ◽  
G.H. Philip
Keyword(s):  
Dna Cleavage ◽  
Magnetic Moments ◽  
Nuclease Activity ◽  
Mixed Ligand ◽  
Mixed Ligand Complexes ◽  
Cleavage Activity ◽  
Redox Couples ◽  
Dna Cleavage Activity ◽  
Calf Thymus ◽  
Heterocyclic Bases

Mixed ligand complexes of nickel(II) with 2,4-dihydroxyacetophenone oxime (DAPO) and 2,4-dihydroxybenzophenone oxime (DBPO) as primary ligands, and pyridine (Py) and imidazole (Im) as secondary ligands were synthesized and characterized by molar conductivity, magnetic moments measurements, as well as by electronic, IR, and 1H-NMR spectroscopy. Electrochemical studies were performed by cyclic voltammetry. The active signals are assignable to the NiIII/II and NiII/I redox couples. The binding interactions between the metal complexes and calf thymus DNA were investigated by absorption and thermal denaturation. The cleavage activity of the complexes was determined using double-stranded pBR322 circular plasmid DNA by gel electrophoresis. All complexes showed increased nuclease activity in the presence of the oxidant H2O2. The nuclease activities of mixed ligand complexes were compared with those of the parent copper(II) complexes.

Cytotoxic copper (II) mixed ligand complexes: Crystal structure and DNA cleavage activity

2011 ◽  
Vol 46 (9) ◽  
pp. 4537-4547 ◽  
Author(s):  
Verasuntharam M. Manikandamathavan ◽  
Royapuram P. Parameswari ◽  
Thomas Weyhermüller ◽  
Hannah R. Vasanthi ◽  
Balachandran Unni Nair
Keyword(s):  
Crystal Structure ◽  
Dna Cleavage ◽  
Mixed Ligand ◽  
Mixed Ligand Complexes ◽  
Cleavage Activity ◽  
Dna Cleavage Activity

scholarly journals A YoeB toxin cleaves both RNA and DNA

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Julia McGillick ◽  
Jessica R. Ames ◽  
Tamiko Murphy ◽  
Christina R. Bourne
Keyword(s):  
Dna Cleavage ◽  
Divalent Cations ◽  
Nuclease Activity ◽  
Dose Dependence ◽  
Cleavage Activity ◽  
Double Stranded Dna ◽  
Dna Cleavage Activity ◽  
Evolutionarily Conserved ◽  
Toxin Protein ◽  
Rna And Dna

AbstractType II toxin-antitoxin systems contain a toxin protein, which mediates diverse interactions within the bacterial cell when it is not bound by its cognate antitoxin protein. These toxins provide a rich source of evolutionarily-conserved tertiary folds that mediate diverse catalytic reactions. These properties make toxins of interest in biotechnology applications, and studies of the catalytic mechanisms continue to provide surprises. In the current work, our studies on a YoeB family toxin from Agrobacterium tumefaciens have revealed a conserved ribosome-independent non-specific nuclease activity. We have quantified the RNA and DNA cleavage activity, revealing they have essentially equivalent dose-dependence while differing in requirements for divalent cations and pH sensitivity. The DNA cleavage activity is as a nickase for any topology of double-stranded DNA, as well as cleaving single-stranded DNA. AtYoeB is able to bind to double-stranded DNA with mid-micromolar affinity. Comparison of the ribosome-dependent and -independent reactions demonstrates an approximate tenfold efficiency imparted by the ribosome. This demonstrates YoeB toxins can act as non-specific nucleases, cleaving both RNA and DNA, in the absence of being bound within the ribosome.

Yb/chitosan catalyzed synthesis of highly substituted piperidine derivatives for potential nuclease activity and DNA binding study

2020 ◽  
Vol 26 ◽  
Author(s):  
Khairujjaman Laskar ◽  
Mohd Farhan ◽  
Aamir Ahmad
Keyword(s):  
Dna Cleavage ◽  
Nuclease Activity ◽  
Substituted Anilines ◽  
Cleavage Activity ◽  
Dna Cleavage Activity ◽  
Nano Catalyst ◽  
Pbr322 Dna ◽  
Catalyst Reusability ◽  
The Stability ◽  
First Time

Background: Herein, a new chitosan supported ytterbium nano-catalyst has been prepared and used for mild, efficient, and expeditious method for the synthesis of substituted piperidine derivatives via three component condensation of substituted anilines, formaldehyde and different cyclic/acyclic active methylene compounds at room temperature. Methods: The catalyst was characterized by FTIR, XRD, SEM, EDX, TEM, ICP-AES and the stability of catalyst was evaluated by TG analysis. The synthesized compound 3,3,11,11-Tetramethyl-15-(phenyl)-15- azadispiro[5.1.5.3]hexadecane-1,5,9,13-tetrone (3a) was explored for pBR322 DNA cleavage activity and genotoxicity for the first time. Further, the interaction study of 3a with CT-DNA was investigated through UV-vis, Fluorescence and Viscosity method. Results: The successful preparation of Yb/chitosan nano-catalyst was proved using various techniques and the catalyst was found effective towards substituted piperidine formations with the catalyst reusability. Further, compound 3a was successfully tested for DNA cleavage activity. In addition, Fluorescence results revealed that compound 3a interacts with DNA having a binding affinity of 4.84 x 104 M-1 . Conclusion: Hence, it could be suggested that compounds bearing spiro-piperidine scaffold synthesized using reusable nano-catalyst would be an effective biological agent.

Synthesis and Characterisation of RuII Polypyridyl Complexes: DNA-Binding, Photocleavage, and Topoisomerase I and II Inhibitory Activity

2013 ◽  
Vol 66 (11) ◽  
pp. 1406 ◽  
Author(s):  
Xiaojun He ◽  
Guang Yang ◽  
Xiaonan Sun ◽  
Lingjun Xie ◽  
Lifeng Tan
Keyword(s):  
Dna Binding ◽  
Dna Cleavage ◽  
Topoisomerase I ◽  
Mixed Ligand ◽  
Dual Inhibitor ◽  
Cleavage Activity ◽  
Dna Cleavage Activity ◽  
Pbr322 Dna ◽  
Dna Strand ◽  
Strand Passage

Two mixed-ligand ruthenium(ii) complexes [Ru(phen)2(cptcp)]2+ (Ru1; phen = 1,10-phenanthroline, cptcp = 2-(4-carbazol-9-yl-phenyl)-1H-1,3,7,8-tetraaza-cyclopenta-[l]-phenanthrene) and [Ru(phen)2(btcpc)]2+ (Ru2; btcpc = 9-butyl-6-(1H-1,3,7,8-tetraaza-cyclo-cyclopenta-[l]-phenanthren-2-yl)-9H-carbazole-3-carbaldehyde) have been synthesised and characterised. The DNA-binding behaviours of the two complexes have been investigated by using spectroscopic and viscosity measurements. Results suggest that the two complexes bind to DNA by intercalation. The photocleavage of plasmid pBR322 DNA indicates that Ru1 exhibits more effective DNA cleavage activity in comparison to that exhibited by Ru2 under the same conditions, and different cleavage mechanisms are determined. Topoisomerase inhibition and DNA strand passage assay confirm that Ru1 may act as an efficient dual inhibitor of topoisomerases I and II, whereas Ru2 may only act as a single inhibitor of topoisomerases II.

scholarly journals Study on the Interaction of 4'-Hydroxychalcones and their Mannich Derivatives with Calf Thymus DNA by TLC and Spectroscopic Methods, a DNA Cleavage Study

2020 ◽  
Vol 14 (1) ◽  
pp. 122-131
Author(s):  
Zsuzsanna Rozmer ◽  
Aline Bernardes ◽  
Caridad N. Pérez ◽  
Pál Perjési
Keyword(s):  
Cell Lines ◽  
Dna Cleavage ◽  
Binding Constant ◽  
Spectroscopic Method ◽  
Spectrophotometric Titration ◽  
Mannich Bases ◽  
Calf Thymus Dna ◽  
Cleavage Activity ◽  
Dna Cleavage Activity ◽  
Calf Thymus

Background: Phenolic Mannich bases derived from hydroxychalcones show remarkable cytotoxic potencies towards cancer cell lines. However, the exact mechanism of action is still partially uncleared. Objective: Interaction of two hydroxychalcones and their Mannich derivatives with calf thymus DNA (ctDNA) has been investigated. Methods: Thin-layer chromatography and UV-Vis spectroscopic method were used for studying the interaction. The binding constant has been determined by UV-Vis spectrophotometric titration. The DNA cleavage activity of the compounds was studied by agarose gel electrophoresis. Results: Interaction of the compounds with ctDNA exhibited relatively high intrinsic binding constant (4-5x104 M-1). The results indicate existence of weak, non-covalent interactions between the investigated derivatives with ctDNA. Some compounds showed a slight DNA cleavage activity with pBR322. Conclusion: The obtained results provide additional knowledge on the previously documented cytotoxicity against tumor cell lines of the hydroxychalcones and their Mannich-derivatives.

scholarly journals Synthesis, Structural Characterization, and Biological Activity Studies of Ni(II) and Zn(II) Complexes

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Palakuri Kavitha ◽  
K. Laxma Reddy
Keyword(s):  
Metal Complexes ◽  
Dna Cleavage ◽  
Spectroscopic Data ◽  
Nuclease Activity ◽  
Molar Conductance ◽  
Agarose Gel Electrophoresis ◽  
Tridentate Ligands ◽  
Cleavage Activity ◽  
Dna Cleavage Activity ◽  
Bacteria And Fungi

Ni(II) and Zn(II) complexes were synthesized from tridentate 3-formyl chromone Schiff bases such as 3-((2-hydroxyphenylimino)methyl)-4H-chromen-4-one (HL1), 2-((4-oxo-4H-chromen-3-yl)methylneamino)benzoic acid (HL2), 3-((3-hydroxypyridin-2-ylimino)methyl)-4H-chromen-4-one (HL3), and 3-((2-mercaptophenylimino)methyl)-4H-chromen-4-one (HL4). All the complexes were characterized in the light of elemental analysis, molar conductance, FTIR, UV-VIS, magnetic, thermal, powder XRD, and SEM studies. The conductance and spectroscopic data suggested that, the ligands act as neutral and monobasic tridentate ligands and form octahedral complexes with general formula [M(L1–4)2]·nH2O (M = Ni(II) and Zn(II)). Metal complexes exhibited pronounced activity against tested bacteria and fungi strains compared to the ligands. In addition metal complexes displayed good antioxidant and moderate nematicidal activities. The cytotoxicity of ligands and their metal complexes have been evaluated by MTT assay. The DNA cleavage activity of the metal complexes was performed using agarose gel electrophoresis in the presence and absence of oxidant H2O2. All metal complexes showed significant nuclease activity in the presence of H2O2.

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