6337-67-3Relevant academic research and scientific papers
Design, synthesis, theoretical calculations and biological evaluation of new non-symmetrical choline kinase inhibitors
Rubio-Ruíz, Belén,Conejo-García, Ana,Ríos-Marco, Pablo,Carrasco-Jiménez, María Paz,Segovia, Josefa,Marco, Carmen,Gallo, Miguel A.,Espinosa, Antonio,Entrena, Antonio
body text, p. 154 - 162 (2012/07/14)
Inhibition of Choline Kinase (ChoK) has been reported as a therapeutical target in the treatment of some kinds of tumor. In this paper, the design and synthesis of new non-symmetrical monocationic ChoK inhibitors is described, bearing a cationic head and an adenine moiety connected by linkers of different lengths. Docking studies indicate that the cationic head of these compounds could be inserted into the choline binding site of the enzyme, while the adenine moiety could be stabilized into the ATP binding site. Docking studies also support the difference of activity of the synthesized compounds, which depends on both the substituent at position 4 of the cationic head and the linker length, being dimethylamine and 1,4-diphenylbutane respectively, the most appropriate ones. Compounds 14 (IC50 = 10.70 ± 0.40 μM) and 17 (IC50 = 6.21 ± 0.97 μM) are the most potent ChoK inhibitors and suitable for further modification with a view to obtain more potent antitumor compounds.
Synthesis and structure-activity analysis of new phosphonium salts with potent activity against African trypanosomes
Taladriz, Andrea,Healy, Alan,Flores Pérez, Eddysson J.,Herrero García, Vanessa,Ríos Martínez, Carlos,Alkhaldi, Abdulsalam A. M.,Eze, Anthonius A.,Kaiser, Marcel,De Koning, Harry P.,Chana, Antonio,Dardonville, Christophe
supporting information; experimental part, p. 2606 - 2622 (2012/06/01)
A series of 73 bisphosphonium salts and 10 monophosphonium salt derivatives were synthesized and tested in vitro against several wild type and resistant lines of Trypanosoma brucei (T. b. rhodesiense STIB900, T. b. brucei strain 427, TbAT1-KO, and TbB48). More than half of the compounds tested showed a submicromolar EC50 against these parasites. The compounds did not display any cross-resistance to existing diamidine therapies, such as pentamidine. In most cases, the compounds displayed a good selectivity index versus human cell lines. None of the known T. b. brucei drug transporters were required for trypanocidal activity, although some of the bisphosphonium compounds inhibited the low affinity pentamidine transporter. It was found that phosphonium drugs act slowly to clear a trypanosome population but that only a short exposure time is needed for irreversible damage to the cells. A comparative molecular field analysis model (CoMFA) was generated to gain insights into the SAR of this class of compounds, identifying key features for trypanocidal activity.
Design, synthesis and characterization of self-assembled As 2L3 and Sb2L3 cryptands
Fontenot, Sean A.,Cangelosi, Virginia M.,Pitt, Melanie A. W.,Sather, Aaron C.,Zakharov, Lev N.,Berryman, Orion B.,Johnson, Darren W.
supporting information; experimental part, p. 12125 - 12131 (2012/03/11)
The syntheses and X-ray crystal structures of six new self-assembled supramolecular As and Sb-containing cryptands are described. Analysis in the context of previously reported As2L3 and Sb 2L3 cryptands reveals that small differences in ligand geometries result in significant differences in the helicity of the complexes and the stereochemistry of the metal coordination within the assembled complexes. Additionally, a new synthetic route is described which involves exposure of reactants to vacuum to help facilitate self-assembly.
Highly conducting π-conjugated molecular junctions covalently bonded to gold electrodes
Chen, Wenbo,Widawsky, Jonathan R.,Vazquez, Hector,Schneebeli, Severin T.,Hybertsen, Mark S.,Breslow, Ronald,Venkataraman, Latha
supporting information; experimental part, p. 17160 - 17163 (2011/12/13)
We measure electronic conductance through single conjugated molecules bonded to Au metal electrodes with direct Au-C covalent bonds using the scanning tunneling microscope based break-junction technique. We start with molecules terminated with trimethyltin end groups that cleave off in situ, resulting in formation of a direct covalent θ bond between the carbon backbone and the gold metal electrodes. The molecular carbon backbone used in this study consist of a conjugated π system that has one terminal methylene group on each end, which bonds to the electrodes, achieving large electronic coupling of the electrodes to the π system. The junctions formed with the prototypical example of 1,4-dimethylenebenzene show a conductance approaching one conductance quantum (G0 = 2e2/h). Junctions formed with methylene-terminated oligophenyls with two to four phenyl units show a 100-fold increase in conductance compared with junctions formed with amine-linked oligophenyls. The conduction mechanism for these longer oligophenyls is tunneling, as they exhibit an exponential dependence of conductance on oligomer length. In addition, density functional theory based calculations for the Au-xylylene-Au junction show near-resonant transmission, with a crossover to tunneling for the longer oligomers.
Homodimeric bis-quaternary heterocyclic ammonium salts as potent acetyl- and butyrylcholinesterase inhibitors: A systematic investigation of the influence of linker and cationic heads over affinity and selectivity
Conejo-García, Ana,Pisani, Leonardo,Del Carmen Nú?ez, Maria,Catto, Marco,Nicolotti, Orazio,Leonetti, Francesco,Campos, Joaquín M.,Gallo, Miguel A.,Espinosa, Antonio,Carotti, Angelo
body text, p. 2627 - 2645 (2011/06/21)
A molecular library of quaternary ammonium salts (QASs), mainly composed of symmetrical bis-quaternary heterocyclic bromides exhibiting choline kinase (ChoK) inhibitory activity, were evaluated for their ability to inhibit acetyl- and butyrylcholinesterase (AChE and BChE, respectively). The molecular framework of QASs consisted of two positively charged heteroaromatic (pyridinium or quinolinium) or sterically hindered aliphatic (quinuclidinium) nitrogen rings kept at an appropriate distance by lipophilic rigid or semirigid linkers. Many homodimeric QASs showed AChE and BChE inhibitory potency in the nanomolar range along with a low enzymatic selectivity. Computational studies on AChE, BChE, and ChoK allowed identification of the key molecular determinants for high affinity and selectivity over either one of the three enzymes and guided the design of a hybrid bis-QAS (56) exhibiting the highest AChE affinity (IC50 = 15 nM) and selectivity over BChE and ChoK (SI = 50 and 562, respectively) and a promising pharmacological potential in myasthenia gravis and neuromuscular blockade.
Energy transfer labels with mechanically linked fluorophores
-
, (2008/06/13)
Mechanically linked energy transfer labels comprising at least one donor fluorophore, at least one acceptor fluorophore, and at least one support member, wherein steric interactions between the donor fluorophore(s), the acceptor fluorophore(s), and/or the support member(s) induce non-covalent association between the fluorophores and the support member(s), thereby forming a three-dimensional macromolecular structure which mechanically links the donor fluorophore(s) and the acceptor fluorophore(s). Fluorescence resonance energy transfer (FRET) occurs from donor fluorophore to acceptor fluorophore through space. No direct connectivity with covalent bonds exists between the fluorophores. Instead, mechanical barriers hold the donor/acceptor fluorophores in place during the FRET process.
Efficient light harvesting by sequential energy transfer across aggregates in polymers of finite conjugational segments with short aliphatic linkages
Peng,Chen,Fann
, p. 11388 - 11397 (2007/10/03)
Interactions between lumophores have a critical influence on the photophysical properties of conjugated polymers. We synthesized a new series of light-harvesting polymers (poly-DSBs, I-IV) of dialkyloxy- or dialkyl- substituted distyrylbenzene (the substituents being methoxy, 2-ethylhexyloxy, and cyclohexyl) with short aliphatic linkage (methylene or ethylene) and examined the effects of interactions between lumophores and of chemical structures on the absorption, emission, and excitation spectra. The proximity between distyrylbenzene lumophores was shown to be critical to the interactions between lumophores and to the energy-transfer processes. In concentrated solutions and solid films, intermolecular aggregates exist resulting from different extents of interactions between lumophores and are found to involve at least three species: loose, compact, and the most aligned aggregates as observed by photoluminescence and excitation spectroscopies. We also found, for the first time, sequential energy transfer from individual lumophores to the most compact, aligned aggregates via the looser intermolecular aggregates, as observed directly by time-resolved fluorescence spectroscopy. Such a process mimics energy transfer in photosynthesis units and is so efficient such that the fluorescence color can be red-shifted drastically by the presence of comparatively few aggregates and that the light evolved from concentrated solutions and films of poly-DSBs I-IV is entirely or almost the aggregation emission. Although the sequential energy-transfer process in fully conjugated electro-/photoluminescent polymers due to inhomogenity other than distributed conjugation lengths has never been directly observed at room temperature, we suggest that events similar to those observed in poly-DSBs in conjugated polymers could occur but on a much shorter time scale, i.e., a few picoseconds.
Samarium(II) Diiodide Mediated Coupling of Bis(bromomethyl)arenes. Facile Synthesis of n>Cyclophanes without using High-Dilution Techniques
Takahashi, Senji,Mori, Nobuo
, p. 2029 - 2032 (2007/10/02)
In the presence of samarium(II) diiodide (Sml2), coupling of 1,3- and 1,4-bis(bromomethyl)benzenes proceeds smoothly to give their cyclic and acyclic oligomers.Use of 1.2 equiv. of Sml2 gives 1,2-bis(3- and 4-bromomethylphenyl)ethanes, respectively, in 95percent yield, and the use of 5.0 equiv. of Sml2 affords n>metacyclophanes and n>paracyclpphanes (n = 2, 3 and 4), respectively, in satisfactory yields.By using 5.0 equiv. of Sml2, 2-bromo- and 2-methoxy-1,4-bis(bromomethyl)benzenes and 1,4- and 2,6-bis(bromomethyl)naphthalenes each give only one of several expected isomeric cyclophanes as the major cyclic oligomer.
A simple synthetic method of cyclophanes by Lanthanoid-mediated coupling of bis(bromomethyl)benzenes
Takahashi, Senji,Mori, Nobuo
, p. 13 - 14 (2007/10/02)
The coupling of bis(bromomethyl)benzenes with iodized samarium, cerium or misch metal gives cyclophanes in satisfactory yields in a short time.
Synthesis and Photocyclization of -, - and Cyclophanediene
Thulin, Bengt,Wennerstroem, Olof
, p. 297 - 302 (2007/10/02)
Three cyclophanes, -, - and cyclophanediene, 1, 5 and 6, respectively, have been prepared by double Wittig reactions.On irradiation under oxidative conditions, cyclophanes 1 and 6 give bi-4,5-phenanthrylene, 2, and (3,6)-p
