120491-88-5Relevant articles and documents
Design and synthesis of phosphorylated pyridine-based ligands for lanthanide complexation. Part 1
Ziessel, Raymond,Steffen, Alexandre,Starck, Matthieu
, p. 3713 - 3716 (2012)
Several new ligands constructed from a pyridine-ethynylnaphthalene platform have been engineered with a chelating pocket comprising bisdimethylaminocarboxylate/phosphonate or bisdimethylaminophosphonate units. Selective hydrolysis provides pockets with four to six anionic carboxylate or phosphate functions suitable for lanthanide complexation. Linkage at the opposite side of a flexible hanging arm either via a triple bond or through an amide tether offers the possibility of further use of these ligands for bioconjugation. Protocols to link the dedicated pockets via hydrophilic flexible chain to Biotin are also detailed.
A mitochondria-targeted macrocyclic Mn(II) superoxide dismutase mimetic
Kelso, Geoffrey F.,Smith, Robin A. J.,Maroz, Andrej,Anderson, Robert F.,Cocheme, Helena M.,Logan, Angela,Prime, Tracy A.,James, Andrew M.,Ross, Meredith F.,Murphy, Michael P.,Peskin, Alexander V.,Winterbourn, Christine C.,Brooker, Sally,Porteous, Carolyn M.
, p. 1237 - 1246,10 (2012)
Superoxide (O2s-) is the proximal mitochondrial reactive oxygen species underlying pathology and redox signaling. This central role prioritizes development of a mitochondria-targeted reagent selective for controlling O2s-. We have conjugated a mitochondria-targeting triphenylphosphonium (TPP) cation to a O2 s--selective pentaaza macrocyclic Mn(II) superoxide dismutase (SOD) mimetic to make MitoSOD, a mitochondria-targeted SOD mimetic. MitoSOD showed rapid and extensive membrane potential-dependent uptake into mitochondria without loss of Mn and retained SOD activity. Pulse radiolysis measurements confirmed that MitoSOD was a very effective catalytic SOD mimetic. MitoSOD also catalyzes the ascorbate-dependent reduction of O2s-. The combination of mitochondrial uptake and O2s- scavenging by MitoSOD decreased inactivation of the matrix enzyme aconitase caused by O2s-. MitoSOD is an effective mitochondria-targeted macrocyclic SOD mimetic that selectively protects mitochondria from O2s- damage.
Photocytotoxicity of Oligothienyl-Functionalized Chelates That Sensitize LnIII Luminescence and Generate 1O2
Johnson, Katherine R.,Lombardi, Vincent C.,de Bettencourt-Dias, Ana
supporting information, p. 12060 - 12066 (2020/08/21)
Three new compounds containing a heptadentate lanthanide (LnIII) ion chelator functionalized with oligothiophenes, nThept(COOH)4 (n=1, 2, or 3), were isolated. Their LnIII complexes not only display the characteristic metal-centered emission in the visible or near-infrared (NIR) but also generate singlet oxygen (1O2). Luminescence efficiencies (?Ln) for [Eu1Thept(COO)4]? and [Eu2Thept(COO)4]? are ?Eu=3 percent and 0.5 percent in TRIS buffer and 33 percent and 3 percent in 95 percent ethanol, respectively. 3Thept(COO)44? does not sensitize EuIII emission due to its low-lying triplet state. Near infra-red (NIR) luminescence is observed for all NIR-emitting LnIII and ligands with efficiencies of ?Yb=0.002 percent, 0.005 percent and 0.04 percent for [YbnThept(COO)4]? (n=1, 2, or 3), and ?Nd=0.0007 percent, 0.002 percent and 0.02 percent for [NdnThept(COO)4]? (n=1, 2, or 3) in TRIS buffer. In 95 percent ethanol, quantum yields of NIR luminescence increase and are ?Yb=0.5 percent, 0.31 percent and 0.05 percent for [YbnThept(COO)4]? (n=1, 2, or 3), and ?Nd=0.40 percent, 0.45 percent and 0.12 percent for [NdnThept(COO)4]? (n=1, 2, or 3). All complexes are capable of generating 1O2 in 95 percent ethanol with ?1Ο2 efficiencies which range from 2 percent to 29 percent. These complexes are toxic to HeLa cells when irradiated with UV light (λexc=365 nm) for two minutes. IC50 values for the LnIII complexes are in the range 15.2–16.2 μm; the most potent compound is [Nd2Thept(COO)4]?. The cell death mechanisms are further explored using an Annexin V—propidium iodide assay which suggests that cell death occurs through both apoptosis and necrosis.
COMPOUNDS AND THEIR USE AS PDE4 ACTIVATORS
-
Page/Page column 90, (2019/10/29)
The present invention relates to compounds as defined herein, which are activators of long form cyclic nucleotide phosphodiesterase-4 (PDE4) enzymes (isoforms) and to therapies using these activators. In particular, the invention relates to these activator compounds for use in a method for the treatment or prevention of disorders requiring a reduction of second messenger responses mediated by cyclic 3',5-adenosine monophosphate (cAMP).
Azobenzene-Equipped Covalent Organic Framework: Light-Operated Reservoir
Das, Gobinda,Prakasam, Thirumurugan,Addicoat, Matthew A.,Sharma, Sudhir Kumar,Ravaux, Florent,Mathew, Renny,Baias, Maria,Jagannathan, Ramesh,Olson, Mark A.,Trabolsi, Ali
, p. 19078 - 19087 (2019/11/28)
Light-operated materials have gained significant attention for their potential technological importance. To achieve molecular motion within extended networks, stimuli-responsive units require free space. The majority of the so far reported 2D-extended org
New advances in the synthesis of tripyridinophane macrocycles suitable to enhance the luminescence of Ln(III) ions in aqueous solution
Leygue, Nadine,Perez e I?iguez De Heredia, Aritz,Galaup, Chantal,Benoist, Eric,Lamarque, Laurent,Picard, Claude
, p. 4272 - 4287 (2018/07/06)
A series of four new 18-membered hexaaza macrocyclic ligands bearing three endocyclic pyridine units and acetate or methylenephosphonate pendant arms has been prepared. The new synthetic procedure is based on the use of amine and diamine precursors incorporating masked carboxylate or phosphonate functions and on an efficient sodium template effect which controls the crucial macrocyclization step (yields of macrocyclization reactions: 62–88%). This procedure appears as a suitable alternative compared to the classical Richman-Atkins methodology generally used for the preparation of this class of macrocycles. As demonstrated with the EuIII and TbIII complexes derived from two ligands, these tripyridinophane chelators form luminescent and stable mononuclear LnIII complexes in aqueous solution at physiological pH. In such a medium, TbIII complexes exhibit a brightness of 1700 (λexc = 279 nm) and 3000 (λexc = 268 nm) M?1 cm?1.
The assembly of "s3N"-ligands decorated with an azo-dye as potential sensors for heavy metal ions
Rasheed,McDouall,Muryn,Raftery,Vitorica-Yrezabal,Quayle
, p. 5229 - 5239 (2017/04/27)
An "S3N-ligand azo-dye" conjugate has been synthesised with a view to the development of a sensor for heavy metal ions. Complexation of this system with Ag(i), Hg(ii) and Cu(ii) salts has been investigated and an X-ray structure has been obtained for a Hg(ii) complex. Complexation of the conjugated dye to these metals results in a bathochromic shift in the absorption maximum of the azo dye, an effect which is most pronounced for Cu(ii).
The Synthesis of Group 10 and 11 Metal Complexes of 3,6,9-Trithia-1-(2,6)-pyridinacyclodecaphane and Their Use in A3-Coupling Reactions
Rasheed, Omer K.,Bawn, Carlo,Davies, David,Raftery, James,Vitorica-Yrzebal, I?igo,Pritchard, Robin,Zhou, Huimin,Quayle, Peter
supporting information, p. 5252 - 5261 (2017/09/29)
The reaction between 3,6,9-trithia-1(2,6)-pyridinacyclodecaphane and representative group 10 and 11 metal salts [Cu(NO3)2, NiCl2 or Ag(CF3CO2)] afforded 1:1 complexes, which in the case of CuII and AgI were characterised by single-crystal X-ray crystallography. The catalytic activity of these complexes in A3-coupling reactions between aldehydes, terminal alkynes and amines was assessed in both protic (water) and aprotic (toluene) media. These A3-reactions prove to be more efficient, proceed with lower catalyst loadings and with faster reaction rates, when conducted in a focused microwave reactor as compared to the same reactions promoted by standard, thermal, modes of activation.
The Influence of para Substituents in Bis(N-Heterocyclic Carbene) Palladium Pincer Complexes for Electrocatalytic CO2 Reduction
Therrien, Jeffrey A.,Wolf, Michael O.
supporting information, p. 1161 - 1172 (2017/02/15)
The effect of modifying the pyridyl para position of lutidine-linked bis(N-heterocyclic carbene) Pd pincer complexes is studied both experimentally (R = OMe, H, Br, and COOR) and computationally, showing a strong effect on the first reduction potential of the complex and allowing the reduction potential to be tuned over a wide range in relation to the Hammett σp constant of the para substituent. The effect of the pyridyl para substituent on electron density of the metal center, frontier orbital energies, and dissociation energy of the trans ligand are also investigated in the context of reactivity with CO2 through electrochemical characterization of the complexes under N2 and CO2 and controlled potential electrolysis experiments where CO2 is reduced to CO.
3D Structure Determination of an Unstable Transient Enzyme Intermediate by Paramagnetic NMR Spectroscopy
Chen, Jia-Liang,Wang, Xiao,Yang, Feng,Cao, Chan,Otting, Gottfried,Su, Xun-Cheng
supporting information, p. 13744 - 13748 (2016/10/26)
Enzyme catalysis relies on conformational plasticity, but structural information on transient intermediates is difficult to obtain. We show that the three-dimensional (3D) structure of an unstable, low-abundance enzymatic intermediate can be determined by nuclear magnetic resonance (NMR) spectroscopy. The approach is demonstrated for Staphylococcus aureus sortase A (SrtA), which is an established drug target and biotechnological reagent. SrtA is a transpeptidase that converts an amide bond of a substrate peptide into a thioester. By measuring pseudocontact shifts (PCSs) generated by a site-specific cysteine-reactive paramagnetic tag that does not react with the active-site residue Cys184, a sufficient number of restraints were collected to determine the 3D structure of the unstable thioester intermediate of SrtA that is present only as a minor species under non-equilibrium conditions. The 3D structure reveals structural changes that protect the thioester intermediate against hydrolysis.
