39621-11-9Relevant academic research and scientific papers
A Design Strategy for Single-Stranded Helicates using Pyridine-Hydrazone Ligands and PbII
Lobo, Maureen J.,Moratti, Stephen C.,Hanton, Lyall R.
, p. 1184 - 1193 (2019)
The reactions of py-hz ligands (L1–L5) with Pb(CF3SO3)2?H2O resulted in some rare examples of discrete single-stranded helical PbII complexes. L1 and L2 formed non-helical mononuclear complexes [PbL1(CF3SO3)2]?CHCl3 and PbL2(CF3SO3)2][PbL2CF3SO3]CF3SO3?CH3CN, which reflected the high coordination number and effective saturation of PbII by the ligands. The reaction of L3 with PbII resulted in a dinuclear meso-helicate [Pb2L3(CF3SO3)2Br]CF3SO3?CH3CN with a stereochemically-active lone pair on PbII. L4 directed single-stranded helicates with PbII, including [Pb2L4(CF3SO3)3]CF3SO3?CH3CN and [Pb2L4CF3SO3(CH3OH)2](CF3SO3)3?2 CH3OH?2 H2O. The acryloyl-modified py-hz ligand L5 formed helical and non-helical complexes with PbII, including a trinuclear PbII complex [Pb3L5(CF3SO3)5]CF3SO3?3CH3CN?Et2O. The high denticity of the long-stranded py-hz ligands L4 and L5 was essential to the formation of single-stranded helicates with PbII.
Aggregation of metallo-supramolecular architectures by metallo-assembled hydrogen bonding sites
Lavalette, Arnaud,Tuna, Floriana,Clarkson, Guy,Alcock, Nathaniel W.,Hannon, Michael J.
, p. 2666 - 2667 (2003)
Metal-ligand interactions are used not only to design metallo- supramolecular architectures but also to assemble multiple hydrogen bond sites at the periphery of these architectures. The hydrogen bond sites aggregate the architectures into polymeric array
New chiral ligands, pyridinooxathianes, for palladium-catalyzed asymmetric allylic alkylation
Okuyama, Yuko,Nakano, Hiroto,Kabuto, Chizuko,Nozawa, Erica,Takahashi, Kouichi,Hongo, Hiroshi
, p. 457 - 469 (2002)
New types of pyridinooxathiane ligands have been synthesized and their abilities as chiral catalysts examined in the palladium-catalyzed allylic alkylation of 1,3-diphenyl-2-propenyl acetate with dimethyl malonate.
An easy entry into Schiff base molecules bearing a pendant primary alcohol function for hydrogen bonding
Ziessel, Raymond,Nguyen, Patrick
, p. 223 - 232 (2005)
A series of mono-oxidized pyridine, bipyridine, terpyridine and pyridine/pyridazine frameworks were prepared using MnO2 as oxidant. Corresponding Schiff bases were prepared with aromatic or aliphatic amines carrying various functions such as pa
New pyrazolino and pyrrolidino[60]fullerenes: the introduction of the hydrazone moiety for the formation of metal complexes
Romero, Elkin L.,Cabrera-Espinoza, Andrea,Ortiz-Pe?a, Nathaly,Soto-Monsalve, Mónica,Zuluaga, Fabio,D'Vries, Richard F.,Chaur, Manuel N.
, (2017)
The [3 + 2] cycloaddition reaction of C60 with pyridine-derived hydrazones (acting as dipolar reagents) was successfully conducted resulting in fullerene derivatives 5a, 5b. The compounds were characterized by means of NMR, UV–Vis spectroscopy, and X-ray crystallography. The electrochemical behavior was also investigated. The fulleropyrazoline 5a exhibits anodically shifted reduction potentials of about 100 mV when compared with those for C60, whereas 5b exhibits cathodic shifts relative to pristine C60. The complexation reaction of 5b with metallic ions (Zn2+, Cd2+, and Fe2+) was achieved. Job and Benesi–Hildebrand analysis confirmed the formation of complexes with a molar ratio of 1:1 and binding constants between 2.26 × 105 and 1.59 × 105 M?1. Electrochemistry of these complexes showed a marked influence of the metal ion on the reduction potentials. Copyright
A Chemical Strategy for Protease Substrate Profiling
Griswold, Andrew R.,Cifani, Paolo,Rao, Sahana D.,Axelrod, Abram J.,Miele, Matthew M.,Hendrickson, Ronald C.,Kentsis, Alex,Bachovchin, Daniel A.
, p. 901 - 6,907 (2019)
The dipeptidyl peptidases (DPPs) regulate hormones, cytokines, and neuropeptides by cleaving dipeptides after proline from their amino termini. Due to technical challenges, many DPP substrates remain unknown. Here, we introduce a simple method, termed CHOPS (chemical enrichment of protease substrates), for the discovery of protease substrates. CHOPS exploits a 2-pyridinecarboxaldehyde (2PCA)-biotin probe, which selectively biotinylates protein N-termini except those with proline in the second position. CHOPS can, in theory, discover substrates for any protease, but is particularly well suited to discover canonical DPP substrates, as cleaved but not intact DPP substrates can be identified by gel electrophoresis or mass spectrometry. Using CHOPS, we show that DPP8 and DPP9, enzymes that control the Nlrp1 inflammasome through an unknown mechanism, do not directly cleave Nlrp1. We further show that DPP9 robustly cleaves short peptides but not full-length proteins. More generally, this work delineates a practical technology for identifying protease substrates, which we anticipate will complement available “N-terminomic” approaches. Proteases regulate countless (patho)physiological processes, but the identification of protease substrates is challenging. Here, Griswold et al. introduce a simple chemoproteomic strategy, termed CHOPS, for profiling protease substrates. Using CHOPS, the authors identify the cleavage specificities of proteases in cellular lysates and show that DPP9 preferentially processes short peptides.
Selective oxidation of a single primary alcohol function in oligopyridine frameworks
Ziessel, Raymond,Nguyen, Patrick,Douce, Laurent,Cesario, Michele,Estournes, Claude
, p. 2865 - 2868 (2004)
(Equation Presented) A variety of mono-oxidized pyridine, bipyridine, terpyridine, and pyridine/pyridazine are readily prepared under mild conditions using Pyrolusite MnO2. This phase has been characterized by means of X-ray powder diffraction
Detection of ferric ions in a gram-positive bacterial cell: Staphylococcus aureus
Manandhar, Erendra,Johnson, Ashley D. G.,Watson, William M.,Dickerson, Shelby D.,Sahukhal, Gyan S.,Elasri, Mohamed O.,Fronczek, Frank R.,Cragg, Peter J.,Wallace, Karl J.
, p. 380 - 401 (2020)
A rhodamine-based chemosensor was synthesized and found to selectively bind ferric ions over other metal ions (Na+, K+, Ca2+, Mg2+, Fe2+, Zn2+, Cd2+, Co2+, Hg2+ Cr3+, Al3+) in an organic-aqueous mixture (CH3CN-MES). Upon addition of ferric ions, the spirolactam ring opens, producing a visual color change and a fluorescence intensity increase, i.e. a “turn on” optical response at 577 nm is observed. The chemosensor coordinates to ferric ions in 1:1 stoichiometry with a calculated K a = 3.5 × 104 mol?dm?3 by fluorescence spectroscopy and a LoD of 27 ppb. The chemosensor was reversible upon addition of the Fe3+ chelator desferrioxamine. One- and two-dimensional NMR experiments with Al3+ ions aided in understanding of the coordination environment of the ferric ion with the chemosensor, which were confirmed by molecular modeling calculations. X-ray quality crystals of the chemosensor were obtained, and the solid-state structure is reported. Confocal microscopy was used to detect free ferric ions in Staphylococcus aureus.
Control of self-assembly through the influence of terminal hydroxymethyl groups on the metal coordination of pyrimidine?hydrazone CU(ii) complexes
Hutchinson, Daniel J.,Hanton, Lyall R.,Moratti, Stephen C.
, p. 5923 - 5934 (2010)
The synthesis and characterization of 6-hydroxymethylpyridine-2- carboxaldehyde (2-methyl-pyrimidine-4,6-diyl)bis(1-methylhydrazone) (1) is reported. Ligand 1 was designed as a ditopic pyrimidine?hydrazone molecular strand with hydroxymethyl groups attached to the terminal pyridine rings. Coordination of 1 with Cu(ClO4)2·6H2O or Cu(SO3CF3)2·4H2O in a 1:2 molar ratio resulted in the dinuclear Cu(II) complexes [Cu21(CH 3CN)4](ClO4)4·CH 3CN (4) and [Cu21(SO3CF3) 2(CH3CN)2](SO3CF3) 2·CH3CN (5) · X-ray crystallography and 1H NMR NOESY experiments showed that 1 adopted a horseshoe shape with both pyrimidine?hydrazone (pym?hyz) bonds in a transoid conformation, while 4 and 5 were linear in shape, with both pym?hyz bonds in a cisoid conformation. Coordination of 1 with Cu(ClO4)2·6H2O or Cu(SO3CF3)2·4H2O in a 1:1 molar ratio resulted in three different bent complexes, [Cu(1H)(ClO 4)2](ClO4) (6), [Cu(1H)(CH3CN)] (ClO4)3·0.5H2O (7), and [Cu1(SO 3CF3)]2(SO3CF3) 2·CH3CN (8), where the pym?hyz bond of the occupied coordination site adopted a cisoid conformation, while the pym?hyz bond of the unoccupied site retained a transoid conformation. Both 6 and 7 showed protonation of the pyridine nitrogen donor in the empty coordination site; complex 8, however, was not protonated. A variety of Cu(II) coordination geometries were seen in structures 4 to 8, including distorted octahedral, trigonal bipyramidal, and square pyramidal geometries. Coordination of the hydroxymethyl arm in the mononuclear Cu(II) complexes 6, 7, and 8 appeared to inhibit the formation of a [2 × 2] grid by blocking further access to the Cu(II) coordination sphere. In addition, the terminal hydroxymethyl groups contributed to the supramolecular structures of the complexes through coordination to the Cu(II) ions and hydrogen bonding.
Magnetic investigation in di- And tetranuclear lanthanide complexes
Wu, Jianfeng,Liu, Dan,Yang, Qianqian,Ge, Yan,Tang, Jinkui,Qi, Zhenhui
supporting information, p. 2200 - 2207 (2021/02/06)
By using a crab-like hydrazone ligand, dinuclear and tetranuclear dysprosium-based complexesDy2andDy4have been isolated. Magnetic investigation reveals that complexDy2shows typical single-molecule magnet behavior under a zero field, benefiting from the ferromagnetic coupling between the DyIIIions, whileDy4possesses a diamagnetic ground state with the anisotropy axes of DyIIIions in centripetal arrangement. The magnetic anisotropies and couplings were confirmed byab initiocalculations.
