- Linking of antitumor trans NHC-Pt(II) complexes to G-quadruplex DNA ligand for telomeric targeting
-
G-quadruplex structures (G4) are promising anticancerous targets. A great number of small molecules targeting these structures have already been identified through biophysical methods. In cellulo, some of them are able to target either telomeric DNA and/o
- Betzer, Jean-Fran?ois,Nuter, Frédérick,Chtchigrovsky, Mélanie,Hamon, Florian,Kellermann, Guillaume,Ali, Samar,Calméjane, Marie-Ange,Roque, Sylvain,Poupon, Jo?l,Cresteil, Thierry,Teulade-Fichou, Marie-Paule,Marinetti, Angela,Bombard, Sophie
-
-
Read Online
- Nucleophilic Substitution Reactions at Planar Four-co-ordinate Monoanionic Platinum(II) Complexes
-
The kinetics of displacement of chloride from complex anions of the type - (pydca = pyridine-2,6-dicarboxylate; R = H, Cl or OMe) by a number of anionic and neutral nucleophiles have been studied in aqueous solution, at 25.0 deg C, I = 0.50 mol dm-3 (LiClO4).Apart from the reactions with OH-, the reactivities of the substrates are not greatly sensitive to the nature of the substituent in the 4 position.Anionic nucleophiles can be as much as two orders of magnitude less reactive than neutral nucleophiles with similar n0Pt values.The rate law for the reaction with OH- takes the form -dln/dt = ks + k3->2, where ks is the first-order rate constant for the solvolytic pathway observed in all the substitution reactions, and where k3 is sensitive to the basicity of the nitrogen in the terdentate ligand.
- Pitteri, Bruno,Cattalini, Lucio,Chessa, Gavino,Marangoni, Giampaolo,Stevanato, Nicoletta,Tobe, Martin L.
-
-
Read Online
- Heavy metal complexes of 4-chlorodipicolinic acid - structural, spectral and thermal correlations
-
The ligand, 4-chloro-2,6-dipicolinic acid (H2PDA-Cl), and its two heavy metal complexes, [Ag(HDPA-Cl)(H2DPA-Cl)·2H2O] (1) and {[Cd(μ2-H2O)(H2O)(PDA-Cl)]}n (2), were prepared and then characterized by single-crystal X-ray diffraction. In addition, spectral and thermal correlations with structural results complete their solid-state description and facilitate complex 3 ([Pb(DPA-Cl)]) composition determinations. Complex 1 crystallizes in a monoclinic space group C2/c and each DPA-Cl ligand is tridentate to Ag(I) through the pyridine N and two monodentate carboxyl O atoms. The carboxy group with carbonyl C1 is semideprotonated and forms a symmetric hydrogen bond with a carboxy group of a neighboring complex. Complex 2 crystallizes in a triclinic lattice with space group P (Formula presented.) The Cd(II) ions are seven-coordinate and the coordination polyhedra can be described as a distorted pentagonal bipyramid. IR data are consistent with monodentate coordination of the carboxylate to Ag(I), Cd(II), and Pb(II) and observed wavenumber shifts confirm PDA-Cl ligand coordination to Pb(II) in 3. Thermal stability of anhydrous complexes indicates the metal–ligand interactions. The thermal stability of prepared compounds is reflected by the strength of interaction between metal–ligand and hydrogen bonds.
- Vargová,Almá?i,Gyepes,Vetráková
-
-
Read Online
- Synthesis, characterization, and spectroscopic properties of three novel pentadentate copper(II) complexes related to the metalchelating inhibitors against DNA binding with HIV-EP1
-
Three potentially five-coordinate peptide ligands having a pyridine and two histidine moieties, were synthesized to study their copper(II) complexation. Blue copper(II) complexes with deprotonated amide groups were isolated from methanolic solutions of the corresponding ligands with equimolar Cu(OAc) 2·H2O. The structures of two of them were determined by X-ray crystallography. The Cu is coordinated to five nitrogen atoms in both complexes; the coordination geometry was a distorted square pyramid in one, and intermediate between a square pyramid and trigonal bipyramid in the other. EPR spectra in frozen methanol solutions at 77 K as well as visible absorption spectra indicate that the distortion of the geometry around the copper is reduced by the introduction of an alkylamine substituent on the pyridine of the ligand and that the substituted complexes distort toward trigonal bipyramidal geometry compared to the unsubstituted one in solution. The Royal Society of Chemistry 2001.
- Kurosaki, Hiromasa,Sharma, Rakesh Kumar,Aoki, Sachiko,Inoue, Teruhiko,Okamoto, Yoshinari,Sugiura, Yukio,Doi, Mitsunobu,Ishida, Toshimasa,Otsuka, Masami,Goto, Masafumi
-
-
Read Online
- A formal anti-Markovnikov hydroalkoxylation of allylic alcohols with a ruthenium catalyst
-
Hydroalkoxylation of C-C double bonds was achieved through the use of a ruthenium catalyst. The reaction of allylic alcohols with nucleophilic alcohols was carried out in the presence of a ruthenium catalyst prepared by RuClH(CO)(PPh3)3 and 2,6-bis(n-butyliminomethyl)-4-(piperidin-1-yl)pyridine under mild reaction conditions to afford the corresponding γ-alkoxypropanols in good yield.
- Nakamura, Yushi,Ohta, Tetsuo,Oe, Yohei
-
supporting information
p. 288 - 291
(2018/02/14)
-
- Dipicolinic Acid Derivatives as Inhibitors of New Delhi Metallo-β-lactamase-1
-
The efficacy of β-lactam antibiotics is threatened by the emergence and global spread of metallo-β-lactamase (MBL) mediated resistance, specifically New Delhi metallo-β-lactamase-1 (NDM-1). By utilization of fragment-based drug discovery (FBDD), a new class of inhibitors for NDM-1 and two related β-lactamases, IMP-1 and VIM-2, was identified. On the basis of 2,6-dipicolinic acid (DPA), several libraries were synthesized for structure-activity relationship (SAR) analysis. Inhibitor 36 (IC50 = 80 nM) was identified to be highly selective for MBLs when compared to other Zn(II) metalloenzymes. While DPA displayed a propensity to chelate metal ions from NDM-1, 36 formed a stable NDM-1:Zn(II):inhibitor ternary complex, as demonstrated by 1H NMR, electron paramagnetic resonance (EPR) spectroscopy, equilibrium dialysis, intrinsic tryptophan fluorescence emission, and UV-vis spectroscopy. When coadministered with 36 (at concentrations nontoxic to mammalian cells), the minimum inhibitory concentrations (MICs) of imipenem against clinical isolates of Eschericia coli and Klebsiella pneumoniae harboring NDM-1 were reduced to susceptible levels.
- Chen, Allie Y.,Thomas, Pei W.,Stewart, Alesha C.,Bergstrom, Alexander,Cheng, Zishuo,Miller, Callie,Bethel, Christopher R.,Marshall, Steven H.,Credille, Cy V.,Riley, Christopher L.,Page, Richard C.,Bonomo, Robert A.,Crowder, Michael W.,Tierney, David L.,Fast, Walter,Cohen, Seth M.
-
p. 7267 - 7283
(2017/09/22)
-
- Modified Colorants and Inkjet Ink Compositions Comprising Modified Colorants
-
The present invention relates to a modified colorant comprising a colorant having attached at least one organic group. Various embodiments of the organic group are disclosed. For each of these embodiments, preferably the organic group has a defined calciu
- -
-
Paragraph 0146-0147
(2016/04/09)
-
- Luminescent lanthanide complex, and articles and inks containing the luminescent complex
-
Luminescent lanthanide complex and inks containing the complex as well as its method of production and article including the complex, wherein the complex includes the formula: wherein M is chosen from the alkali cations Li+, Na+, K+, Rb+ and Cs+ and mixtures thereof and is present to neutralize charge of the complex; wherein Ln is chosen from the trivalent rare-earth cations of Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Yb and mixtures thereof; wherein R is a C5 to C6 heteroaryl: wherein Y is an optionally substituted C3-C8 heterocycloalkyl moiety linked to R by an N atom; wherein n is an integer of 3 or 5; and wherein x is an integer of 0 or 1.
- -
-
-
- LUMINESCENT LANTHANIDE COMPLEX, AND ARTICLES AND INKS CONTAINING THE LUMINESCENT COMPLEX
-
Luminescent lanthanide complex and inks containing the complex as well as its method of production and article including the complex, wherein the complex includes the formula: wherein M is chosen from the alkali cations Li+, Na+, K+, Rb+ and Cs+ and mixtures thereof and is present to neutralize charge of the complex; wherein Ln is chosen from the trivalent rare-earth cations of Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Yb and mixtures thereof; wherein R is a C5 to C6 heteroaryl: wherein Y is an optionally substituted C3-C8 heterocycloalkyl moiety linked to R by an N atom; wherein n is an integer of 3 or 5; and wherein x is an integer of 0 or 1.
- -
-
Page/Page column
(2014/04/17)
-
- Unprecedented strong lewis bases - Synthesis and methyl cation affinities of dimethylamino-substituted terpyridines
-
A versatile method for the synthesis of functionalized 2,2′:6′, 2″-terpyridines by assembly of the terminal pyridine rings is presented. The cyclization precursors - bis-β-ketoenamides - are prepared from 4-substituted 2,6-pyridinedicarboxylic acids and a
- Hommes, Paul,Fischer, Christina,Lindner, Christoph,Zipse, Hendrik,Reissig, Hans-Ulrich
-
supporting information
p. 7647 - 7651
(2014/08/05)
-
- Structure-activity relationship study of BACE1 inhibitors possessing a chelidonic or 2,6-pyridinedicarboxylic scaffold at the P2 position
-
We have previously reported potent substrate-based pentapeptidic BACE1 inhibitors possessing a hydroxymethylcarbonyl isostere as a substrate transition-state mimic. While these inhibitors exhibited potent activities in enzymatic and cellular assays (KMI-4
- Hamada, Yoshio,Suzuki, Kenji,Nakanishi, Tomoya,Sarma, Diganta,Ohta, Hiroko,Yamaguchi, Ryoji,Yamasaki, Moe,Hidaka, Koushi,Ishiura, Shoichi,Kiso, Yoshiaki
-
p. 618 - 623
(2014/01/23)
-
- Pyridostatin analogues promote telomere dysfunction and long-term growth inhibition in human cancer cells
-
The synthesis, biophysical and biological evaluation of a series of G-quadruplex interacting small molecules based on a N,N′-bis(quinolinyl) pyridine-2,6-dicarboxamide scaffold is described. The synthetic analogues were evaluated for their ability to stabilize telomeric G-quadruplex DNA, some of which showed very high stabilization potential associated with high selectivity over double-stranded DNA. The compounds exhibited growth arrest of cancer cells with detectable selectivity over normal cells. Long-time growth arrest was accompanied by senescence, where telomeric dysfunction is a predominant mechanism together with the accumulation of restricted DNA damage sites in the genome. Our data emphasize the potential of a senescence-mediated anticancer therapy through the use of G-quadruplex targeting small molecules based on the molecular framework of pyridostatin.
- Müller, Sebastian,Sanders, Deborah A.,Di Antonio, Marco,Matsis, Stephanos,Riou, Jean-Fran?ois,Rodriguez, Rapha?l,Balasubramanian, Shankar
-
supporting information; experimental part
p. 6537 - 6546
(2012/09/08)
-
- Effects of a halogenated G-quadruplex ligand from the pyridine dicarboxamide series on the terminal sequence of XpYp telomere in HT1080 cells
-
Non-canonical four-stranded structures called G-quadruplexes can form among telomere repeats during its replication. Small molecule ligands able to interact and to stabilize G-quadruplexes were shown to disrupt the binding of essential telomeric components, such as POT1 and to trigger a telomeric dysfunction associated with a delayed growth arrest in tumor cells. We describe here the chemical synthesis and the G-quadruplex binding properties of three halogenated analogs of the 360A ligand that belongs to the 2,6 pyridine dicarboxamide series. 360A is now commonly used as a benchmark both for biophysical and cellular assays as this compound was shown to display a potent affinity and selectivity for telomeric G-quadruplex DNA over duplex DNA and to induce delayed growth inhibition in HT1080 tumor cell line. Two biophysical assays indicate that, in most cases, the presence of the halogen atom seems to slightly improve the interaction with the telomeric quadruplex. For stability reasons, the bromo derivative (360A-Br) was selected for the cellular assays. Since POT1 participates to the fine tuning of the C-strand end resection during telomere replication, we investigated the effect of 360A-Br to alter the terminal nucleotide composition of XpYp telomere in HT1080 cells using C-STELA. HT1080 cells treated for up to 24 days with 360A-Br presented some minor but significant variations of C-strand terminal nucleotide composition, also observed with a partial siRNA depletion of POT1. The relevance of these minor modifications of the telomeric C-strand resection induced by 360A-Br in HT1080 cells are discussed.
- Sidibe, Assitan,Hamon, Florian,Largy, Eric,Gomez, Dennis,Teulade-Fichou, Marie-Paule,Trentesaux, Chantal,Riou, Jean-Francois
-
p. 2559 - 2568
(2013/01/15)
-
- Electronic effects in 4-substituted bis(imino)pyridines and the corresponding reduced iron compounds
-
A family of 4-substituted bis(imino)pyridines, 4-X-iPrPDI (4-X-iPrPDI = 2,6-(2,6-iPr2-C6H 3N=CMe)2-4-X-C5H2N; X = CF 3, tBu, Bn, NMe2), has been synthesized and the iron coordination chemistry studied. Sodium amalgam reduction of the iron dihalides (4-X-iPrPDI)FeX2 (X = Cl, Br) in the presence of excess carbon monoxide furnished the corresponding iron dicarbonyl compounds (4-X-iPrPDI)Fe(CO)2. Equilibrium mixtures of the four- and five-coordinate iron dinitrogen compounds (4-X-iPrPDI)FeN 2 and (4-X-iPrPDI)Fe(N2)2 were prepared by performing the sodium amalgam reduction of the iron dihalides under a dinitrogen atmosphere. Electrochemical and spectroscopic measurements were conducted on the free ligands and the iron derivatives to systematically evaluate the influence of each para pyridine substituent on the electronic structure of the compound.
- Darmon, Jonathan M.,Turner, Zoe R.,Lobkovsky, Emil,Chirik, Paul J.
-
scheme or table
p. 2275 - 2285
(2012/06/04)
-
- Nucleic acids targeted to drugs: SELEX against a quadruplex ligand
-
A number of small molecules demonstrate selective recognition of G-quadruplexes and are able to stabilize their formation. In this work, we performed the synthesis of two biotin-tagged G4 ligands and analyzed their interactions with DNA by two complementa
- Renaud De La Faverie, Amandine,Hamon, Florian,Di Primo, Carmelo,Largy, Eric,Dausse, Eric,Delaurire, Laurence,Landras-Guetta, Corinne,Toulmé, Jean-Jacques,Teulade-Fichou, Marie-Paule,Mergny, Jean-Louis
-
experimental part
p. 1357 - 1367
(2012/07/01)
-
- Ruthenium-catalyzed asymmetric epoxidation of olefins using H 2O2, part I: Synthesis of new chiral N,N,N,-tridentate pybox and pyboxazine ligands and their ruthenium complexes
-
The synthesis of chiral tridentate N,N,N-pyridine-2.6-bisoxazolines 3 (pyhox ligands) and N,N,N-pyridine-2.6-bisoxazines 4 (pyboxazine ligands) is described in detail. These novel ligands constitute a useful tool-box for the application in asymmetric catalysis. Compounds 3 and 4 are conveniently prepared by cyclization of enantiomerically pure α- or β-amino al cohols with dimethyl pyridine-2,6-dicarboximidate. The corresponding ruthenium complexes are efficient asymmetric epoxidation catalysts and have been prepared in good yield and fully char acterized by spectroscopic means. Four of these ruthenium complexes have been characterized by X-ray crystallography. For the first time the molecular structure of a pyboxazine complex (2,6-bis-[(4S)-4-phenyl-5,6- dihydro-4H-[1,3]oxazinyl]pyridine)(pyridine-2,6-dicarboxylate)ruthenium (S)-2aa, is presented.
- Tse, Man Kin,Bhor, Santosh,Klawonn, Markus,Anilkumar, Gopinathan,Jiao, Haijun,Doebler, Christian,Spannenberg, Anke,Magerlein, Wolfgang,Hugl, Herbert,Beller, Matthias
-
p. 1855 - 1874
(2008/02/02)
-
- A flexible and versatile strategy for the covalent immobilization of chiral catalysts based on pyridinebis(oxazoline) ligands
-
Flexible and versatile methods have been developed for the immobilization of chiral pyridinebis(oxazoline) ligands by covalent bonding to a solid support, either by grafting or by polymerization. Different spacers can easily be introduced to modulate the
- Cornejo, Alfonso,Fraile, Jose M.,Garcia, Jose I.,Gil, Maria J.,Luis, Santiago V.,Martinez-Merino, Victor,Mayoral, Jose A.
-
p. 5536 - 5544
(2007/10/03)
-
- Synthesis of new Cu(II)-chelating ligand amphiphiles and their esterolytic properties in cationic micelles
-
Four new tetradentate 2,6-disubstituted pyridine and tridentate 2-substituted pyridine ligands were synthesized. Two of these compounds possessed a metal ion binding subunit in the form of a 2,6-disubstituted-4-N,N′-dimethylamine pyridine moiety. Cu2+-complexes of these ligands incorporated in cetyltrimethylammonium bromide (CTABr) micelles speeded the cleavage of p-nitrophenyldiphenyl phosphate and p-nitrophenyl hexanoate at pH 7.6. On the basis of a kinetic version of Job plot analysis, a 1:1 ligand/Cu2+ stoichiometry was found to be the most active species. In CTABr micelles, the pKa values for the Cu2+-coordinated hydroxyl or pendant-CH2OH in these ligands were between 7.8 and 7.9. The metallomicellar systems displayed catalytic (turnover) behavior in the presence of excess substrates.
- Bhattacharya, Santanu,Snehalatha, Karnam,Kumar, V. Praveen
-
p. 2741 - 2747
(2007/10/03)
-
- A new versatile methodology for the synthesis of 4-halogenated-6-diethylcarbamoylpyridine-2-carboxylic acids
-
Convenient syntheses of dipicolinic or chelidamic acid derivatives including 4-X-6-diethylcarbamoyl-pyridine-2-carboxylic acid (X=H, Cl, Br) and 4-chloro-6-(3-oxo-3-phenylpropionyl)pyridine-2-carboxylic acid methyl ester are described. These compounds are important synthons for the synthesis of non-symmetric tridentate aromatic chelating agents as well as for the design of ditopic ligands targeted for the elaboration of functional dimetallic helicates.
- Chauvin, Anne-Sophie,Tripier, Rapha?l,Bünzli, Jean-Claude G.
-
p. 3089 - 3091
(2007/10/03)
-
- Effect of a halogenide substituent on the stability and photophysical properties of lanthanide triple-stranded helicates with ditopic ligands derived from bis(benzimidazolyl)pyridine
-
Bis {1-ethyl-2-[6-(N,N-diethylcarbamoyl)-4-halogenopyridin-2-yl]benzimidazol-5-yl} methane (halogeno = chloro, LE; bromo, LF) have been synthesized as ditopic receptors for the development of lanthanide-containing helicates able to couple with biological material and to test the influence of the halogeno substituent on the wrapping process, the structure of the resulting dimetallic edifices, and the photophysical properties of the encapsulated ions. The stability of the [Eu2(L)3]6+ helicates, as determined by NMR competitive titrations, decreases by respectively one (LF) and three (LE) orders of magnitude compared to the value found for the unsubstituted ligand (LB) although it remains large, log β23 = 23.8 (LF) and 21.8 (LE) in acetonitrile. The [Ln2(LE)3]6+ helicates are shown to be isostructural in acetonitrile over the lanthanide series (Pr to Yb) and the crystal structure of [Tb2(LB)3]6+ appears to be a good model for their solution structure, as demonstrated by paramagnetic NMR measurements (lanthanide induced shift method) and relaxation time determination. Ligand LE appears to be a fair sensitiser of EuIII, the quantum yield of [Eu2(LE)3]6+ being 25% larger than that found for [Eu2(LB)3]6+, but the ligand 3ππ* state and Tb(5D4) excited level are in resonance, which limits the sensitisation of TbIII. High resolution luminescence spectra of [Eu2(LE)3]6+, both in solution and in the solid state, are presented and discussed in terms of site symmetry and vibronic coupling mechanisms. The Royal Society of Chemistry 2000.
- Iglesias, Carlos Platas,Elhabiri, Mourad,Hollenstein, Marcel,Buenzli, Jean-Claude G.,Piguet, Claude
-
p. 2031 - 2043
(2007/10/03)
-
- Design and synthesis of complementary components for the formation of self-assembled supramolecular rigid rods
-
The complementary components AP2 and AU2, resulting respectively from the linking of diacylaminopyridine and uracil derivatives to an anthracenic core, have been designed in order to self-assemble, through hydrogen bonding, into polymeric supramolecular rigid rods (AP2, AU2)(n). The synthesis of these compounds is reported.
- Kotera, Mitsu,Lehn, Jean-Marie,Vigneron, Jean-Pierre
-
p. 1953 - 1972
(2007/10/02)
-
- A Novel Reagent for Labelling Macromolecules with Intensely Luminescent Lanthanide Complexes
-
A novel bifunctional chelator, 4-iodoacetamidodipicolinic acid, has been synthesized in three steps starting with chelidamic acid, and used to prepare protein conjugates that form stable and intensely luminescent complexes with Tb(III) and Eu(III).The excited state lifetime of Tb(III) complexes with this reagent was 1.25 ms, permitting its use for ultrasensitive time-resolved luminescence assays.
- Lamture, Jagannath B.,Wensel, Theodore G.
-
p. 4141 - 4144
(2007/10/02)
-
- OXIDATION OF ALKENES BY A CHIRAL NON-PORPHYRINIC OXIDIZING CATALYST BASED ON THE BLEOMYCIN-Fe(II) COMPLEX
-
A synthetic model for the metal binding site of bleomycin with 4-dimethylaminopyridine nucleus, namely PYML-8, shows dioxygen activation up to 125percent of that of bleomycin. β-Methylstyrene is oxidized with the Fe(III)-H2O2, Fe(III)-PhIO, or Fe(II)-O2 complex systems of PYML-8 to give a set of products including optically active epoxide.The product composition is dependent on iron, oxygen source, and reducing agent employed, suggesting varied active species generated from each complex system.
- Suga, Akira,Sugiyama, Toru,Otsuka, Masami,Ohno, Masaji,Sugiura, Yukio,Maeda, Kenji
-
p. 1191 - 1204
(2007/10/02)
-
- Cation Complexing Properties of Synthetic Macrocyclic Polyether-Diester Ligands Containing the Pyridine Subcyclic Unit
-
Ten new macrocyclic polyether-diester compounds containing a pyridine subcyclic unit substituted in the 4 position with chloro or methoxy groups have been prepared.These compounds along with their unsubstituted pyridine analogues form strong complexes wit
- Bradshaw, J. S.,Maas, G. E.,Lamb, J. D.,Izatt, R. M.,Christensen J. J.
-
p. 467 - 474
(2007/10/02)
-
