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Enderle AG, Bosso M, Groß R, Heiland M, Bollini M, Culzoni MJ, Kirchhoff F, Münch J, Streb C. Increased in vitro Anti-HIV Activity of Caffeinium-Functionalized Polyoxometalates. ChemMedChem 2021; 16:2727-2730. [PMID: 33908695 PMCID: PMC8518980 DOI: 10.1002/cmdc.202100281] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Indexed: 11/10/2022]
Abstract
Polyoxometalates (POMs), molecular metal oxide anions, are inorganic clusters with promising antiviral activity. Herein we report increased anti-HIV-1 activity of a POM when electrostatically combined with organic counter-cations. To this end, Keggin-type cerium tungstate POMs have been combined with organic methyl-caffeinium (Caf) cations, and their cytotoxicity, antiviral activity and mode of action have been studied. The novel compound, Caf4 K[β2 -CeSiW11 O39 ]×H2 O, exhibits sub-nanomolar antiviral activity and inhibits HIV-1 infectivity by acting on an early step of the viral infection cycle. This work demonstrates that combination of POM anions and organic bioactive cations can be a powerful new strategy to increase antiviral activity of these inorganic compounds.
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Affiliation(s)
- Ana G. Enderle
- Institute of Inorganic Chemistry IUlm UniversityAlbert-Einstein-Allee 1189081UlmGermany
- Medicinal Chemistry LabCentro de Investigaciones en Bionanociencias (CIBION), CONICETGodoy Cruz, 2390C1425FQDCiudad de Buenos AiresArgentina
- Laboratorio de Desarrollo Analítico y Quimiometría (LADAQ)Universidad Nacional del Litoral – CONICETCiudad UniversitariaParaje El Pozo, CC242S3000Santa FeArgentina
| | - Matteo Bosso
- Institute of Molecular VirologyUlm University Medical CenterMeyerhofstraße 189081UlmGermany
| | - Rüdiger Groß
- Institute of Molecular VirologyUlm University Medical CenterMeyerhofstraße 189081UlmGermany
| | - Magdalena Heiland
- Institute of Inorganic Chemistry IUlm UniversityAlbert-Einstein-Allee 1189081UlmGermany
| | - Mariela Bollini
- Medicinal Chemistry LabCentro de Investigaciones en Bionanociencias (CIBION), CONICETGodoy Cruz, 2390C1425FQDCiudad de Buenos AiresArgentina
| | - María J. Culzoni
- Laboratorio de Desarrollo Analítico y Quimiometría (LADAQ)Universidad Nacional del Litoral – CONICETCiudad UniversitariaParaje El Pozo, CC242S3000Santa FeArgentina
| | - Frank Kirchhoff
- Institute of Molecular VirologyUlm University Medical CenterMeyerhofstraße 189081UlmGermany
| | - Jan Münch
- Institute of Molecular VirologyUlm University Medical CenterMeyerhofstraße 189081UlmGermany
| | - Carsten Streb
- Institute of Inorganic Chemistry IUlm UniversityAlbert-Einstein-Allee 1189081UlmGermany
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Dailing EA, Kilchrist KV, Tierney JW, Fletcher RB, Evans BC, Duvall CL. Modifying Cell Membranes with Anionic Polymer Amphiphiles Potentiates Intracellular Delivery of Cationic Peptides. ACS Appl Mater Interfaces 2020; 12:50222-50235. [PMID: 33124813 PMCID: PMC9082340 DOI: 10.1021/acsami.0c13304] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Rapid, facile, and noncovalent cell membrane modification with alkyl-grafted anionic polymers was sought as an approach to enhance intracellular delivery and bioactivity of cationic peptides. We synthesized a library of acrylic acid-based copolymers containing varying amounts of an amine-reactive pentafluorophenyl acrylate monomer followed by postpolymerization modification with a series of alkyl amines to afford precise control over the length and density of aliphatic alkyl side chains. This synthetic strategy enabled systematic investigation of the effect of the polymer structure on membrane binding, potentiation of peptide cell uptake, pH-dependent disruption of lipid bilayers for endosome escape, and intracellular bioavailability. A subset of these polymers exhibited pKa of ∼6.8, which facilitated stable membrane association at physiological pH and rapid, pH-dependent endosomal disruption upon endocytosis as quantified in Galectin-8-YFP reporter cells. Cationic cell penetrating peptide (CPP) uptake was enhanced up to 15-fold in vascular smooth muscle cells in vitro when peptide treatment was preceded by a 30-min pretreatment with lead candidate polymers. We also designed and implemented a new and highly sensitive assay for measuring the intracellular bioavailability of CPPs based on the NanoLuciferase (NanoLuc) technology previously developed for measuring intracellular protein-protein interactions. Using this split luciferase class of assay, polymer pretreatment enhanced intracellular delivery of the CPP-modified HiBiT peptide up to 30-fold relative to CPP-HiBiT without polymer pretreatment (p < 0.05). The overall structural analyses show that polymers containing 50:50 or 70:30 molar ratios of carboxyl groups to alkyl side chains of 6-8 carbons maximized peptide uptake, pH-dependent membrane disruption, and intracellular bioavailability and that this potentiation effect was maximized by pairing with CPPs with high cationic charge density. These results demonstrate a rapid, mild method for polymer modification of cell surfaces to potentiate intracellular delivery, endosome escape, and bioactivity of cationic peptides.
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Affiliation(s)
- Eric A Dailing
- Department of Biomedical Engineering, Vanderbilt University, PMB 351634, Nashville, Tennessee 37235, United States
| | - Kameron V Kilchrist
- Department of Biomedical Engineering, Vanderbilt University, PMB 351634, Nashville, Tennessee 37235, United States
| | - J William Tierney
- Department of Biomedical Engineering, Vanderbilt University, PMB 351634, Nashville, Tennessee 37235, United States
| | - R Brock Fletcher
- Department of Biomedical Engineering, Vanderbilt University, PMB 351634, Nashville, Tennessee 37235, United States
| | - Brian C Evans
- Department of Biomedical Engineering, Vanderbilt University, PMB 351634, Nashville, Tennessee 37235, United States
| | - Craig L Duvall
- Department of Biomedical Engineering, Vanderbilt University, PMB 351634, Nashville, Tennessee 37235, United States
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Bloch J, Kradolfer S, L. Gianetti T, Ostendorf D, Dey S, Mougel V, Grützmacher H. Synthesis and Characterization of Ion Pairs between Alkaline Metal Ions and Anionic Anti-Aromatic and Aromatic Hydrocarbons with π-Conjugated Central Seven- and Eight-Membered Rings. Molecules 2020; 25:molecules25204742. [PMID: 33076581 PMCID: PMC7594067 DOI: 10.3390/molecules25204742] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 10/02/2020] [Accepted: 10/04/2020] [Indexed: 11/29/2022] Open
Abstract
The synthesis, isolation and full characterization of ion pairs between alkaline metal ions (Li+, Na+, K+) and mono-anions and dianions obtained from 5H-dibenzo[a,d]cycloheptenyl (C15H11 = trop) is reported. According to Nuclear Magnetic Resonance (NMR) spectroscopy, single crystal X-ray analysis and Density Functional Theory (DFT) calculations, the trop‒ and trop2−• anions show anti-aromatic properties which are dependent on the counter cation M+ and solvent molecules serving as co-ligands. For comparison, the disodium and dipotassium salt of the dianion of dibenzo[a,e]cyclooctatetraene (C16H12 = dbcot) were prepared, which show classical aromatic character. A d8-Rh(I) complex of trop− was prepared and the structure shows a distortion of the C15H11 ligand into a conjugated 10π -benzo pentadienide unit—to which the Rh(I) center is coordinated—and an aromatic 6π electron benzo group which is non-coordinated. Electron transfer reactions between neutral and anionic trop and dbcot species show that the anti-aromatic compounds obtained from trop are significantly stronger reductants.
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Affiliation(s)
- Jan Bloch
- Department of Chemistry and Applied Biosciences, ETH Zürich, 8093 Zürich, Switzerland; (J.B.); (S.K.); (D.O.); (S.D.); (V.M.)
| | - Stefan Kradolfer
- Department of Chemistry and Applied Biosciences, ETH Zürich, 8093 Zürich, Switzerland; (J.B.); (S.K.); (D.O.); (S.D.); (V.M.)
| | - Thomas L. Gianetti
- Department of Chemistry & Biochemistry, 1306 E. University Blvd., Tucson, AZ 85719, USA;
| | - Detlev Ostendorf
- Department of Chemistry and Applied Biosciences, ETH Zürich, 8093 Zürich, Switzerland; (J.B.); (S.K.); (D.O.); (S.D.); (V.M.)
| | - Subal Dey
- Department of Chemistry and Applied Biosciences, ETH Zürich, 8093 Zürich, Switzerland; (J.B.); (S.K.); (D.O.); (S.D.); (V.M.)
| | - Victor Mougel
- Department of Chemistry and Applied Biosciences, ETH Zürich, 8093 Zürich, Switzerland; (J.B.); (S.K.); (D.O.); (S.D.); (V.M.)
| | - Hansjörg Grützmacher
- Department of Chemistry and Applied Biosciences, ETH Zürich, 8093 Zürich, Switzerland; (J.B.); (S.K.); (D.O.); (S.D.); (V.M.)
- Correspondence:
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Alvares DS, Viegas TG, Ruggiero Neto J. The effect of pH on the lytic activity of a synthetic mastoparan-like peptide in anionic model membranes. Chem Phys Lipids 2018; 216:54-64. [PMID: 30253128 DOI: 10.1016/j.chemphyslip.2018.09.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 08/20/2018] [Accepted: 09/11/2018] [Indexed: 12/28/2022]
Abstract
Peptide sequences containing acidic and basic residues could potentially have their net charges modulated by bulk pH with a possible influence on their lytic activity in lipid vesicles. The present study reports on a biophysical investigation of these modulatory effects on the synthetic mastoparan-like peptide L1A (IDGLKAIWKKVADLLKNT-NH2). At pH 10.0 L1A was 6 times more efficient in lysing large anionic (1-palmitoyl-oleoyl-sn-glycero-3-phosphocholine (POPC):1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoglycerol (POPG)/(8:2)) unilamellar vesicles (LUVs) than at pH 4.0. Despite the reduction of 60% in the L1A net charge in basic pH its affinity for this vesicle was almost insensitive to pH. On the other hand, L1A insertion into monolayers was dramatically influenced by subphase condition, showing that, in the neutral and basic subphases, the peptide induced surface pressure changes that surpassed the membrane lateral pressure, being able to destabilize a bilayer structure. In addition, in the basic subphase, visualization of the compression isotherms of co-spread 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC):POPG (8:2) + 4.8 mol% L1A showed that the peptide induced significant changes in solid lipid domains, indicating its capability in perturbing lipid-packing. An insight into L1A lytic activity was also obtained in giant unilamellar vesicles (GUVs) using phase contrast microscopy. The suppression of L1A lytic activity at acidic pH is in keeping with its lower insertion capability and ability to disturb the lipid monolayer. The lytic activity observed under neutral and basic conditions showed a quick and stochastic leakage following a lag-time. The permeability and the leakage-time averaged over at least 14 single GUVs were dependent on the bulk condition. At basic pH, permeability is higher and quicker than in a neutral medium in good accordance with the lipid-packing perturbation.
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Affiliation(s)
- Dayane S Alvares
- UNESP - São Paulo State University, IBILCE, Department of Physics, São José do Rio Preto, SP, Brazil
| | - Taisa G Viegas
- UNESP - São Paulo State University, IBILCE, Department of Physics, São José do Rio Preto, SP, Brazil
| | - João Ruggiero Neto
- UNESP - São Paulo State University, IBILCE, Department of Physics, São José do Rio Preto, SP, Brazil.
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5
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Jicsinszky L, Caporaso M, Calcio Gaudino E, Giovannoli C, Cravotto G. Synthesis of Randomly Substituted Anionic Cyclodextrins in Ball Milling. Molecules 2017; 22:molecules22030485. [PMID: 28335503 PMCID: PMC6155213 DOI: 10.3390/molecules22030485] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Revised: 03/12/2017] [Accepted: 03/16/2017] [Indexed: 12/03/2022] Open
Abstract
A number of influencing factors mean that the random substitution of cyclodextrins (CD) in solution is difficult to reproduce. Reaction assembly in mechanochemistry reduces the number of these factors. However, lack of water can improve the reaction outcomes by minimizing the reagent’s hydrolysis. High-energy ball milling is an efficient, green and simple method for one-step reactions and usually reduces degradation and byproduct formation. Anionic CD derivatives have successfully been synthesized in the solid state, using a planetary ball mill. Comparison with solution reactions, the solvent-free conditions strongly reduced the reagent hydrolysis and resulted in products of higher degree of substitution (DS) with more homogeneous DS distribution. The synthesis of anionic CD derivatives can be effectively performed under mechanochemical activation without significant changes to the substitution pattern but the DS distributions were considerably different from the products of solution syntheses.
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Affiliation(s)
- László Jicsinszky
- Department of Drug Science and Technology, University of Turin, Via P. Giuria 7, 10125 Turin, Italy.
| | - Marina Caporaso
- Department of Drug Science and Technology, University of Turin, Via P. Giuria 7, 10125 Turin, Italy.
| | - Emanuela Calcio Gaudino
- Department of Drug Science and Technology, University of Turin, Via P. Giuria 7, 10125 Turin, Italy.
| | - Cristina Giovannoli
- Department of Chemistry, University of Turin, Via P. Giuria 7, 10125 Turin, Italy.
| | - Giancarlo Cravotto
- Department of Drug Science and Technology, University of Turin, Via P. Giuria 7, 10125 Turin, Italy.
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Del Prete S, Vullo D, Di Fonzo P, Osman SM, AlOthman Z, Supuran CT, Capasso C. Anion inhibition profiles of the γ-carbonic anhydrase from the pathogenic bacterium Burkholderia pseudomallei responsible of melioidosis and highly drug resistant to common antibiotics. Bioorg Med Chem 2016; 25:575-580. [PMID: 27914949 DOI: 10.1016/j.bmc.2016.11.021] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Revised: 11/11/2016] [Accepted: 11/12/2016] [Indexed: 12/13/2022]
Abstract
Burkholderia pseudomallei is a Gram-negative saprophytic bacterium responsible of melioidosis, an endemic disease of tropical and sub-tropical regions of the world. A recombinant γ-CA (BpsγCA) identified in the genome of this bacterium was cloned and purified. Its catalytic activity and anion inhibition profiles were investigated. The enzyme was an efficient catalyst for the CO2 hydration showing a kcat of 5.3×105s-1 and kcat/Km of 2.5×107M-1×s-1. The best BpsγCA inhibitors were sulfamide, sulfamic acid, phenylboronic acid and phenylarsonic acid, which showed KI in the range of 49-83μM (these inhibitors showed millimolar inhibition constant against hCA II), followed by diethyldithiocarbamate, selenate, tellurate, perrhenate, selenocyanate, trithiocarbonate, tetraborato, pyrophosphate, stannate, carbonate, bicarbonate, azide, cyanide, thiocyanate and cyanate with KIs in the range of 0.55-9.1mM. In our laboratories, work is in progress to resolve the X-ray crystal structures of BpsγCA, which may allow the development of small molecule inhibitors with desired properties for targeting and inhibiting specifically the bacterial over the human CAs, considering the fact that B. pseudomallei is involved in a serious bacterial disease.
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Affiliation(s)
- Sonia Del Prete
- Istituto di Bioscienze e Biorisorse, CNR, Via Pietro Castellino 111, Napoli, Italy; Università degliStudi di Firenze, Dipartimento Di Chimica, Laboratorio di Chimica Bioinorganica, Polo Scientifico, Via della Lastruccia 3, 50019 Sesto Fiorentino, Florence, Italy
| | - Daniela Vullo
- Università degliStudi di Firenze, Dipartimento Di Chimica, Laboratorio di Chimica Bioinorganica, Polo Scientifico, Via della Lastruccia 3, 50019 Sesto Fiorentino, Florence, Italy
| | - Pietro Di Fonzo
- Istituto di Bioscienze e Biorisorse, CNR, Via Pietro Castellino 111, Napoli, Italy
| | - Sameh M Osman
- Department of Chemistry, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia
| | - Zeid AlOthman
- Department of Chemistry, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia
| | - Claudiu T Supuran
- Department of Chemistry, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia; Università degli Studi di Firenze, Dipartimento Neurofarba, Sezione di ScienzeFarmaceutiche e Nutraceutiche, Via U. Schiff 6, 50019 Sesto Fiorentino, Florence, Italy.
| | - Clemente Capasso
- Istituto di Bioscienze e Biorisorse, CNR, Via Pietro Castellino 111, Napoli, Italy.
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Li X, Zhang D, Li J. Emission "Off-On" effect from europium complexes triggered by AcO anion: synthesis, characterization and sensing performance. Spectrochim Acta A Mol Biomol Spectrosc 2014; 127:1-9. [PMID: 24632149 DOI: 10.1016/j.saa.2014.02.042] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Revised: 01/24/2014] [Accepted: 02/09/2014] [Indexed: 06/03/2023]
Abstract
In this paper, a series of Eu(III) complexes based on four diamine ligands and two diketone ligands were synthesized. Their single crystal structures were studied, where intermolecular π-π stacking was found. The photophysical parameters of these Eu(III) complexes were measured, along with their ligand triplet levels. The energy transfer mechanism between ligand and metal center was discussed in detail. Energy transfer roll-back was found in Eu(III) complexes owing large-conjugated diamine ligands, compromising emissive performance. This energy transfer roll-back, however, could be stopped by the presence of AcO anion, leading to Eu(III) complex emission enhancement. The sensing performance of such Eu(III) complexes was thus investigated in detail. High sensitivity and selectivity were observed.
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Affiliation(s)
- Xiaogang Li
- Industrial & Commercial College, Hebei University, Baoding 071000, China.
| | - Dong Zhang
- Institute of Penology, The Central Institute for Correctional Police, Baoding 071000, China
| | - Jing Li
- Agricultural University of Hebei, Baoding 071000, China
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8
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Sybachin AV, Zaborova OV, Orlov VN, Semenyuk PI, Ballauff M, Kesselman E, Schmidt J, Talmon Y, Menger FM, Yaroslavov AA. Complexes between anionic liposomes and spherical polycationic brushes. An assembly of assemblies. Langmuir 2014; 30:2441-2447. [PMID: 24533780 DOI: 10.1021/la4036248] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
This paper has at its objective the assembling of liposomal assemblies onto nanoparticles. In this manner, one generates nanoparticles with a high loading capacity. Thus, spherical spherical polycationic "brushes" (SPBs) were synthesized by graft polymerizing a cationic monomer, (trimethylammonium)ethylmethacrylate chloride, onto the surface of monodisperse polystyrene particles, ca. 100 nm in diameter. These particles were complexed with small unilamellar anionic liposomes, 40-60 nm in diameter, composed of egg lecithin (EL) and anionic phosphatidylserine (PS(1-)) in PS(1-)/EL ratios from 0.10 to 0.54, a key parameter designated as ν. These complexes were then characterized according to electrophoretic mobility, dynamic light scattering, conductivity, fluorescence, and cryogenic transmission electron microscopy, with the following main conclusions: (a) All added liposomes are totally associated with SPBs up to a certain saturation concentration (specific for each ν value). (b) The number of liposomes per SPB particle varies from 40 (ν = 0.1) to 14 (ν = 0.5). (c) At sufficiently high liposome concentrations, the SPBs experience an overall change from positive to negative charge. (d) SPB complexes tend to aggregate when their initial positive charge has been precisely neutralized by the anionic liposomes. Aggregation is impeded by either positive charge at lower lipid concentrations, or negative charge at higher lipid concentrations. (e) The liposomes remain intact (i.e., do not leak) when associated with SPBs, at ν ≤ 0.5. (f) Complete SPB/liposome dissociation occurs at external [NaCl] = 0.3 M for ν = 0.1 and at 0.6 M for ν = 0.5. Liposomes with ν = 0.54 do not dissociate from the SPBs even in NaCl solutions up to 1.0 M. (g) Complexation of the PS(1-)/EL liposomes to the SPBs induces flip-flop of PS(1-) from the inner leaflet to the outer leaflet. (h) The differences in the ability of PS(1-) (a cylindrical lipid) and CL(2-) (a conical lipid) to create membranes defects are attributed to geometric factors.
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Affiliation(s)
- A V Sybachin
- Department of Chemistry, M.V. Lomonosov Moscow State University , Leninskie Gory 1-3, 119991 Moscow, Russian Federation
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Aggarwal N, Altgärde N, Svedhem S, Zhang K, Fischer S, Groth T. Study on multilayer structures prepared from heparin and semi-synthetic cellulose sulfates as polyanions and their influence on cellular response. Colloids Surf B Biointerfaces 2013; 116:93-103. [PMID: 24463147 DOI: 10.1016/j.colsurfb.2013.12.043] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Revised: 12/15/2013] [Accepted: 12/20/2013] [Indexed: 11/19/2022]
Abstract
Multilayer coatings of polycationic chitosan paired with polyanionic semi-synthetic cellulose sulfates or heparin were prepared by the layer-by-layer method. Two different cellulose sulfates (CS) with high (CS2.6) and intermediate (CS1.6) sulfation degree were prepared by sulfation of cellulose. Multilayers were fabricated at pH 4 and the resulting films were characterized by several methods. The multilayer 'optical' mass, measured by surface plasmon resonance, showed little differences in the total mass adsorbed irrespective of which polyanion was used. In contrast, 'acoustic' mass, calculated from quartz crystal micro balance with dissipation monitoring, showed the lowest mass and dissipation values for CS2.6 (highest sulfation degree) multilayers indicating formation of stiffer layers compared to heparin and CS1.6 layers which led to higher mass and dissipation values. Water contact angle and zeta potential measurements indicated formation of more distinct layers with using heparin as polyanion, while use of CS1.6 and CS2.6 resulted into more fuzzy intermingled multilayers. CS1.6 multilayers significantly supported adhesion and growth of C2C12 cells where as only few cells attached and started to spread initially on CS2.6 layers but favoured long term cell growth. Contrastingly cells adhered and grew poorly on to the layers of heparin. This present study shows that cellulose sulfates are attractive candidates for multilayer formation as potential substratum for controlled cell adhesion. Since a peculiar interaction of cellulose sulfates with growth factors was found during previous studies, immobilization of cellulose sulfate in multilayer systems might be of great interest for tissue engineering applications.
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Affiliation(s)
- Neha Aggarwal
- Biomedical Materials Group, Institute of Pharmacy, Martin Luther University Halle-Wittenberg, Heinrich-Damerow-Strasse 4, 06120 Halle (Saale), Germany
| | - Noomi Altgärde
- Department of Applied Physics, Chalmers University of Technology, 412 96 Gothenburg, Sweden
| | - Sofia Svedhem
- Department of Applied Physics, Chalmers University of Technology, 412 96 Gothenburg, Sweden
| | - Kai Zhang
- Institute of Macromolecular Chemistry and Paper Chemistry, Technische Universität Darmstadt, Petersenstr. 22, D-64287 Darmstadt, Germany
| | - Steffen Fischer
- Institute of Plant and Wood Chemistry, Dresden University of Technology, Pienner Str. 19, D-01737 Tharandt, Germany
| | - Thomas Groth
- Biomedical Materials Group, Institute of Pharmacy, Martin Luther University Halle-Wittenberg, Heinrich-Damerow-Strasse 4, 06120 Halle (Saale), Germany.
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10
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Liu L, Fei X, Zhu S, Yu L, Zhang B. Self-assembly of anionic gemini surfactant: fluorescence resonance energy transfer and simulation study. Langmuir 2013; 29:5132-5137. [PMID: 23582023 DOI: 10.1021/la304980r] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The interaction of dyes with a sulfonated Gemini surfactant was investigated in aqueous solution using Förster resonance energy transfer with acridine orange (AO) as a donor and rhodamine B (RhB) as an acceptor. Surface tension results showed that AO and RhB have different effects on the self-assembly of the Gemini surfactant, with AO giving a higher critical micelle concentration (cmc) and lower surface tension, while the opposite was observed for RhB. Energy transfer from AO to RhB was observed in the presence of the surfactant, and the energy transfer efficiency initially improved with increased surfactant concentration but then decreased significantly when the surfactant reached a higher concentration due to the formation of larger aggregates, which increased the average distance between AO and RhB. Dynamic light scattering demonstrated the existence of these large aggregates. Moreover, simulations using dissipative particle dynamics supported the experimental results.
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Affiliation(s)
- Lijuan Liu
- School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, People's Republic of China
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11
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Brown P, Butts CP, Eastoe J, Fermin D, Grillo I, Lee HC, Parker D, Plana D, Richardson RM. Anionic surfactant ionic liquids with 1-butyl-3-methyl-imidazolium cations: characterization and application. Langmuir 2012; 28:2502-9. [PMID: 22208500 DOI: 10.1021/la204557t] [Citation(s) in RCA: 149] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
For the first time a series of anionic surfactant ionic liquids (SAILs) has been synthesized based on organic surfactant anions and 1-butyl-3-methyl-imidazolium cations. These compounds are more environmentally friendly and chemically tunable as compared to other common ionic liquids. A detailed investigation of physicochemical properties highlights potential applications from battery design to reaction control, and studies into aqueous aggregation behavior, as well as structuring in pure ILs, point to possible uses in electrochemistry.
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Affiliation(s)
- Paul Brown
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, United Kingdom
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12
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Ertekin A, Kausch CM, Kim Y, Thomas RR. Synthesis, characterization, adsorption, and interfacial rheological properties of four-arm anionic fluorosurfactants. Langmuir 2008; 24:2412-2420. [PMID: 18266395 DOI: 10.1021/la7031175] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Four-arm oligo(fluorooxetane) tetraols containing -CF3 and -C2F5 groups were prepared in reasonable yields by cationic, ring-opening polymerization of fluorinated oxetane monomers using a tetrafunctional, alkoxylated polyol as initiator and BF3.THF as catalyst. The tetraols were then converted to ammonium sulfate salts using oleum followed by neutralization with ammonium hydroxide in excellent yields. The four-arm oligo(fluorooxetane) sulfates (1=-CF3, 2=-C2F5) have an architecture characterized by a hydrophobic core of oligo(fluorooxetane) arms with a hydrophilic sulfate shell and initiator. The four-arm anionic oligo(fluorooxetane)s are surface active with critical micelle concentration values approximately 4.2x10(-6) and 2.4x10(-6) mol/L for 1 and 2, respectively. Surface tension isotherms in pH 8 buffered solution were measured and data fitted parametrically to the Davies surface tension isotherm equation. Molecular areas at saturation were estimated to be approximately 89 and approximately 85 A2 with DeltaGads=-12.7 and -13.2 kcal/mol for 1 and 2, respectively. The results are compared to two-arm, bolaamphiphilic analogues of 1 and 2 and a small molecule, long perfluoroalkyl-chain (-C8F17), anionic fluorosurfactant (Kausch, C. M.; Kim, Y.; Russell, V. M.; Medsker, R. E.; Thomas, R. R. Langmuir 2003, 19, 7182). Dynamic surface tension data for 1 and 2 were analyzed using the Ward-Tordai mass transport equation to yield concentration-dependent diffusion coefficients. In the concentration range approximately 10(-6) mol/L, diffusion coefficients were estimated to be approximately 1-3x10(-5) cm2/s. Dilational interfacial rheological parameters for 1 and 2 were measured. Values of |E| and E' were found to be larger than those of the two-arm analogues of the same perfluoroalkyl chain length while E' 'and phi were found to be smaller. The magnitude of these values reflects the difference in adsorption strength and mass transport and/or relaxation between the two different architectures.
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Affiliation(s)
- Ayça Ertekin
- Department of Polymer Engineering, Polymer Engineering Academic Center, The University of Akron, Akron, Ohio 44325-0301, USA
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13
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Johson JS. Advances in acyl anion and homoenolate catalysis. Curr Opin Drug Discov Devel 2007; 10:691-703. [PMID: 17987521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Umpolung catalysis involving carbonyls is a long-established concept in organic synthesis, but is arguably underdeveloped relative to other modes of catalysis. Acyl anion and homoenolate catalysis provides unique and rapid access to functional group arrays that may otherwise be challenging to synthesize directly. Catalysis is only feasible when a strict set of requirements is met, and to date only a small number of molecules are known to meet these criteria. This review highlights innovative advances that have been made in this field within the past four years and includes research aimed toward catalyst development, new reaction discovery and stereocontrol.
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Affiliation(s)
- Jeffrey S Johson
- University of North Carolina, Department of Chemistry, Chapel Hill, NC 27599-3290, USA.
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14
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Abstract
The characterisation of a series of compounds obtained from Woollins' reagent (W.R.) offers a novel approach to organometallic coordination polymers. The syntheses were achieved by nucleophilic ring-opening reactions of W.R. with metal salts and crystallisation using solvent-diffusion techniques. One-dimensional coordination polymers are formed as a result, and we demonstrate that the dimensionality of the polymers can be influenced by using hydrated metal salts or by the construction of heterometallic arrangements.
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Affiliation(s)
- Weifeng Shi
- Institut für Anorganische Chemie, Universität Karlsruhe, Karlsruhe, Germany
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15
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Fang TT, Zirrolli J, Bendiak B. Differentiation of the anomeric configuration and ring form of glucosyl-glycolaldehyde anions in the gas phase by mass spectrometry: isomeric discrimination between m/z 221 anions derived from disaccharides and chemical synthesis of m/z 221 standards. Carbohydr Res 2006; 342:217-35. [PMID: 17184755 DOI: 10.1016/j.carres.2006.11.021] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2006] [Revised: 11/14/2006] [Accepted: 11/20/2006] [Indexed: 11/29/2022]
Abstract
Mass spectrometry of disaccharides in the negative-ion mode frequently generates product anions of m/z 221. With glucose-containing disaccharides, dissociation of isolated m/z 221 product ions in a Paul trap yielded mass spectra that easily differentiated between both anomeric configurations and ring forms of the ions. These ions were shown to be glucosyl-glycolaldehydes through chemical synthesis of their standards. By labeling the reducing carbonyl oxygen of disaccharides with 18O to mass discriminate between monosaccharides, it was established that the m/z 221 ions are comprised solely of an intact nonreducing sugar with a two-carbon aglycon derived from the reducing sugar, regardless of the disaccharide linkage position. This enabled the anomeric configuration and ring form of the ion to be assigned and the location of the ion to the nonreducing side of a glycosidic linkage to be ascertained. Detailed studies of experimental factors necessary for reproducibility in a Paul trap demonstrated that the unique dissociation patterns that discriminate between the isomeric m/z 221 ions could be obtained from month-to-month in conjunction with an internal energy-input calibrant ion that ensures reproducible energy deposition into isolated m/z 221 ions. In addition, MS/MS fragmentation patterns of disaccharide m/z 341 anions in a Paul trap enabled linkage positions to be assigned, as has been previously reported with other types of mass spectrometers.
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Affiliation(s)
- Tammy T Fang
- Department of Cellular and Developmental Biology and Biomolecular Structure Program, University of Colorado at Denver and Health Sciences Center, Aurora, CO 80045, USA
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16
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Argüello J, Núñez-Vergara LJ, Bollo S, Squella JA. Nitro radical anion formation from nitrofuryl substituted 1,4-dihydropyridine derivatives in mixed and non-aqueous media. Bioelectrochemistry 2006; 69:104-12. [PMID: 16473565 DOI: 10.1016/j.bioelechem.2005.12.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2005] [Revised: 11/15/2005] [Accepted: 12/13/2005] [Indexed: 10/25/2022]
Abstract
Three new nitrofuryl substituted 1,4-dihydropyridine derivatives were electrochemically tested in the scope of newly found compounds useful as chemotherapeutic alternative to the Chagas' disease. All the compounds were capable to produce nitro radical anions sufficiently stabilized in the time window of the cyclic voltammetric experiment. In order to quantify the stability of the nitro radical anion we have calculated the decay constant, k2. Furthermore, from the voltammetric results, some parameters of biological significance as E7(1) (indicative of in vivo nitro radical anion formation) and KO2 (thermodynamic indicator of oxygen redox cycling) have been calculated. From the comparison of E7(1), KO2 and k2 values between the studied nitrofuryl 1,4-DHP derivatives and well-known current drugs an auspicious activity for one of the studied compounds i.e. FDHP2, can be expected.
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Affiliation(s)
- J Argüello
- Bioelectrochemistry Laboratory, Chemical and Pharmaceutical Sciences Faculty, University of Chile, POB 233, Santiago 1, Chile
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17
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Abstract
The binding selectivity of simple pyridyl thioureas in acetonitrile can be completely switched by protonation; hence the neutral thiourea binds acetate, but not chloride or bromide, whereas the protonated thiourea binds strongly to chloride or bromide, but is deprotonated by acetate.
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Affiliation(s)
- Suad Rashdan
- School of Chemistry, University of Southampton, Southampton, UKSO17 1BJ
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18
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Chung YM, Raman B, Kim DS, Ahn KH. Fluorescence modulation in anion sensing by introducing intramolecular H-bonding interactions in host–guest adducts. Chem Commun (Camb) 2006:186-8. [PMID: 16372100 DOI: 10.1039/b510795d] [Citation(s) in RCA: 221] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Fluorescence signaling in anion binding is modulated from quenching to enhancement by intramolecular H-bonding stabilization of anion-ionophore adducts; the intramolecular H-bonding is suggested to suppress the quenching processes otherwise possible and increase the conformational rigidity of the anionic adducts, leading to fluorescence enhancement in a selective fashion towards cyanide ion, among the various anions examined.
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Affiliation(s)
- Yun Mi Chung
- Department of Chemistry and Center for Integrated Molecular Systems, Division of Molecular and Life Science, POSTECH, San 31, Hyoja-dong, Pohang 790-784, Republic of Korea
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19
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Degl'Innocenti A, Pollicino S, Capperucci A. Synthesis and stereoselective functionalization of silylated heterocycles as a new class of formyl anion equivalents. Chem Commun (Camb) 2006:4881-93. [PMID: 17136237 DOI: 10.1039/b608816n] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The fluoride ion-induced reactivity of a series of silyl heterocycles leads to the generation of nucleophilic species capable of interacting with electrophiles, thus disclosing new classes of formyl and acyl anion synthons. Moreover, when reacting stereodefined molecules, the stereoinformation of the reacting carbon-silicon bond is transferred to the newly formed carbon-carbon bond, suggesting possible applications in stereoselective synthesis. Thus, silyl dithiolanes, oxathiolanes, dioxolanes, thiazolidines and oxazolidines can be efficiently and stereoselectively functionalized under fluoride ion conditions in the presence of electrophiles. While direct access to silyl heterocycles is generally either prevented or troublesome, a novel protocol for their synthesis has also been developed, together with a simple general access route to several functionalized and stereodefined mercaptans, building blocks for the construction of silyl heterocycles.
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20
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Abstract
Bucillamine (BUC) is used clinically for the treatment of rheumatoid arthritis. Some of the pharmacological action of BUC has been reported as being dependent on the production of reactive oxygen species (ROS). In this paper the reactivity of BUC with superoxide anion radical (O(2) (*-)) generated from potassium superoxide/18-crown-6 ether dissolved in DMSO, hydroxyl radical (HO(*)) produced in the Cu(2+)-H(2)O(2) reaction, peroxyl radical (ROO(*)) from 2,2'-azobis (2-amidino-propane) dichloride decomposition, and singlet oxygen ((1)O(2)) from a mixture of alkaline aqueous H(2)O(2) and acetonitrile, have been investigated. Chemiluminescence, fluorescence, electron paramagnetic resonance (EPR) spin-trapping techniques and the deoxyribose and oxygen radical absorbance capacity towards ROO(*) (ORAC(ROO)) assays were used to elucidate the anti- and pro-oxidative behaviours of BUC towards ROS. The results indicated that BUC efficiently inhibited chemiluminescence from the O(2) (*-)-generating system at relatively high concentrations (0.5-2 mmol/L); however, at lower concentrations (<0.5 mmol/L) the drug enhanced light emission. The behaviour of BUC was correlated with a capacity to decrease the chemiluminescence signal from the Cu(2+)-H(2)O(2) system; scavenging HO(*) was effective only at high concentrations (1-2 mmol/L) of the drug. Bucillamine also prevented deoxyribose degradation induced by HO(*) in a dose-dependent manner, reaching maximal inhibition (24.5%) at a relative high concentration (1.54 mmol/L). Moreover, BUC reacts with ROO(*); the relative ORAC(ROO) was found to be 0.34 micromol/L Trolox equivalents/micromol sample. The drug showed quenching of (1)O(2)-dependent 2,2,6,6-tetramethylpiperidine-N-oxide radical formation from 2,2,6,6-tetramethyl-piperidine (e.g. 90% inhibition was found at 1 mmol/L concentration). The results showed that BUC may directly scavenge ROS or inhibit reactions generating them. However, the drug may have pro-oxidant activity under some reaction conditions.
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Affiliation(s)
- Aleksandra Kładna
- Department of Medical History and Ethics, Pomeranian Medical Academy, Rybacka 1, 70-204 Szczecin, Poland
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21
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Gardinier JR, Pellechia PJ, Smith MD. Ionic Rotors. Preparation, Structure, and Dynamic Solid-State 2D NMR Study of the 1,4-Diethynylbenzenebis(triphenylborate) Dianion. J Am Chem Soc 2005; 127:12448-9. [PMID: 16144366 DOI: 10.1021/ja053256j] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The reaction between p-(LiC2)2C6H4 (generated in situ from butyllithium and dialkynylbenzene) and 2 equiv of BPh3 affords high yields of [Li(THF)4]2[p-(Ph3BC2)2C6H4], a heretofore missing member of the isoelectronic [p-(Ph3EC2)2C6H4] (E = groups 13-15 element) series. The central phenylene linker is free to rotate in the solid state, as determined by a variable-temperature solid-state 2D spin-echo NMR spectroscopic study. At room temperature, the rate of rotation is at least 20 times faster than that of its carbon-based analogue, presumably a result of Coulombic repulsions minimizing noncovalent interactions between rotating units in the borate salt.
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Affiliation(s)
- James R Gardinier
- Department of Chemistry, Marquette University, Milwaukee, Wisconsin 53201, USA
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22
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Abstract
Electron transfer to perfluoro-1,3-dimethylcyclohexane in moist THF has yielded two quite different products. Tetrabutylammonium iodide irradiated with ultraviolet light gives a tetrabutylammonium enolate, but potassium fluorenone ketyl affords a cyclohexenyl anion. This allylic anion was isolated as its conjugate acid, a rather strong carbon acid. Ring inversion in the anion, measured by (19)F NMR line shape analysis, is characterized by these activation parameter values: DeltaH(++) = 8.84 +/-0.14 kcal/mol and DeltaS(++) = 0.81 +/- 0.6 cal mol(-1) K(-1).
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Affiliation(s)
- Xudong Chen
- Department of Chemistry, Dartmouth College, Hanover, New Hampshire 03755, USA.
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23
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Sutton AD, John GH, Sarsfield MJ, Renshaw JC, May I, Martin LR, Selvage AJ, Collison D, Helliwell M. Spectroscopic Evidence for the Direct Coordination of the Pertechnetate Anion to the Uranyl Cation in [UO2(TcO4)(DPPMO2)2]+. Inorg Chem 2004; 43:5480-2. [PMID: 15332793 DOI: 10.1021/ic049588r] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We report the synthesis and structural characterization of [UO(2)(ReO(4))(DPPMO(2))(2)][ReO(4)] and [UO(2)(Cl)(DPPMO(2))(2)][Cl] (where DPPMO(2) = bis(diphenylphosphino)methane dioxide). In both complexes, the linear uranyl dication is coordinated to two bidentate DPPMO(2) ligands in the equatorial plane with one coordinated and one non-coordinated anion (either perrhenate or chloride). We have also prepared the pertechnetate analogue, and, through (31)P and (99)Tc NMR, we have shown that the cation, [UO(2)(TcO(4))(DPPMO(2))(2)](+), is stable in solution.
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Affiliation(s)
- Andrew D Sutton
- Centre for Radiochemistry Research, Department of Chemistry, The University of Manchester, Manchester M13 9PL, U.K
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24
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Gunnlaugsson T, Davis AP, Hussey GM, Tierney J, Glynn M. Design, synthesis and photophysical studies of simple fluorescent anion PET sensors using charge neutral thiourea receptors. Org Biomol Chem 2004; 2:1856-63. [PMID: 15227537 DOI: 10.1039/b404706k] [Citation(s) in RCA: 196] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The synthesis of four fluorescent photoinduced electron transfer (PET) chemosensors 1-4 for anions is described. These are all based on a simple design employing charge neutral aliphatic or aromatic thiourea anion receptors connected to an anthracene fluorophore via a methylene spacer. Here the anion recognition occurred through 1 : 1 hydrogen bonding between the thiourea protons and the anion, as demonstrated by observing the changes in the (1)H NMR in DMSO-d(6) where the two thiourea protons were shifted downfield upon addition of anions. Whereas 1-3 were designed for the detection of anions such as fluoride, acetate or phosphate, 4 was made for the recognition of N-protected amino acids. All the sensors showed 'ideal' behaviour where only the fluorescence emission was quenched upon anion recognition, due to enhanced efficiency of electron transfer quenching from the receptor to the excited state of the fluorophore. By simply varying the nature of the thiourea substituent it was possible to modulate, or tune, the acidity of the thiourea receptor moiety, altering the sensitivity of the anion recognition. For, the anion selectivity and the degree of the fluorescence quenching were in the order of F(-) > AcO(-) > H(2)PO(4)(-), with Cl(-) or Br(-) not being detected.
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25
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Ley SV, Dixon DJ, Guy RT, Palomero MA, Polara A, Rodriguez F, Sheppard TD. Studies on the generation of enolate anions from butane-2,3-diacetal protected glycolic acid derivatives and subsequent highly diastereoselective coupling reactions with aldehydes and acid chlorides. Org Biomol Chem 2004; 2:3618-27. [PMID: 15592620 DOI: 10.1039/b412790k] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Highly diastereoselective coupling reactions of enolates derived from butane-2,3-diacetal protected glycolic acids 1 and 2 and their alkylated derivatives with aldehydes are reported together with their efficient acid-catalysed deprotection to yield enantiopure anti-2,3-dihydroxyesters. A procedure to provide the corresponding syn-2,3-dihydroxyesters is also described in two cases, proceeding via an acylation-reduction sequence. An usual double addition reaction of butane-2,3-diacetal protected glycolic acid to small aliphatic acid chlorides provides a synthetically useful, densely-functionalised lactone after acidic deprotection.
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Affiliation(s)
- Steven V Ley
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, UK CB2 1EW.
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26
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Fang X, Woodmansee D, Bu X, Bazan GC. The Boratacyclooctatetraene Ligand: An Isoelectronic Trianionic Analogue of the Cyclooctatetraene Dianion. Angew Chem Int Ed Engl 2003; 42:4510-4. [PMID: 14520752 DOI: 10.1002/anie.200351911] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Xiangdong Fang
- Department of Chemistry and Materials, Center for Polymer and Organic Solids, The University of California, Santa Barbara, CA 93106, USA
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27
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Pérollier C, Constant S, Jodry JJ, Bernardinelli G, Lacour J. Mannose derived hexacoordinated phosphate--a generally efficient chiral anion for asymmetric applications. Chem Commun (Camb) 2003:2014-5. [PMID: 12934888 DOI: 10.1039/b305169b] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Mannose derived hexacoordinated phosphate--prepared in two steps from methyl-alpha-D-mannopyranoside--is a chiral anionic auxiliary with broad asymmetric efficiency.
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Affiliation(s)
- Céline Pérollier
- Department of Organic Chemistry, University of Geneva, Quai Ernest Ansermet 30, CH-1211 Geneva 4, Switzerland
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28
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Saavedra JE, Srinivasan A, Bonifant CL, Chu J, Shanklin AP, Flippen-Anderson JL, Rice WG, Turpin JA, Davies KM, Keefer LK. The secondary amine/nitric oxide complex ion R(2)N[N(O)NO](-) as nucleophile and leaving group in S9N)Ar reactions. J Org Chem 2001; 66:3090-8. [PMID: 11325274 DOI: 10.1021/jo0016529] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Ions of structure R(2)N[N(O)NO](-) and their alkylation products have seen increasing use as nitric oxide (NO)-generating agents for biomedical research applications. Here we show that such diazeniumdiolate anions can readily displace halide from a variety of electrophilic aza- or nitroaromatic substrates to form O(2)-arylated derivatives of structure R(2)N-N(O)=N-OAr. The site of arylation and the cis arrangement of the oxygens were confirmed by X-ray crystallography. Displacement by various nucleophiles showed R(2)N[N(O)NO](-) to be a reasonably good leaving group, with rate constants for displacement by hydroxide, methoxide, and isopropylamine that were between those of chloride and fluoride in the S(N)Ar reactions we surveyed. The Meisenheimer intermediate could be spectrally observed. These O(2)-aryl diazeniumdiolates proved capable of reacting with the nucleophilic sulfur of the HIV-1 p7 nucleocapsid protein's zinc finger assembly to eject the zinc, disrupting a structural motif critical to viral replication and suggesting possible utility in the drug discovery realm.
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Affiliation(s)
- J E Saavedra
- Intramural Research Support Program, SAIC Frederick, National Cancer Institute at Frederick, Frederick, Maryland 21702, USA.
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29
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Abstract
Ynolates are carbanions having a triple bond in place of the double bond in enolate anions. Ynolates are ketene anion equivalents, thus ynolates introduce a ketene unit into substrates and the resulting products possess high reactivity. This allows ynolates to undergo unique reaction sequences. For the past 20 years, several methods for the generation of ynolates and their reactions have been developed. Recently, we have developed a novel efficient method for their generation via cleavage of ester dianions. Starting from this success, we have found new reactions of ynolate anions. Ynolate anions react with carbonyl compounds to give beta-lactone enolates, which are converted into olefins with high E-selectivity. It is noteworthy that high E-selectivity was achieved in the synthesis of tetrasubstituted olefins. Utilizing the strong nucleophilicity of the beta-lactone enolates, we have succeeded in the first tandem [2 + 2] cycloaddition-Dieckmann condensation to lead synthetically useful 2,3-disubstituted-2-cycloalkenones in good yields. Ynolate anions were found to react with N-sulfonyl aldimines to give beta-lactams. N-2-methoxyphenyl aldimines efficiently activate their cycloaddition of lithium ynolates via chelation to give beta-lactams and alpha,beta-unsaturated amides. We have demonstrated the high functionality of ynolate anions. Ynolate chemistry has begun and much remains to be discovered.
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Affiliation(s)
- M Shindo
- Institute for Medicinal Resources, University of Tokushima, 1-78, Sho-machi, Tokushima 770-8505, Japan
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30
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Gerken M, Dixon DA, Schrobilgen GJ. The OsO4F-, OsO4F2(2)-, and OsO3F3- anions, their study by vibrational and NMR spectroscopy and density functional theory calculations, and the X-ray crystal structures of [N(CH3)4][OsO4F] and [N(CH3)4][OsO3F3]. Inorg Chem 2000; 39:4244-55. [PMID: 11196919 DOI: 10.1021/ic000259i] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The fluoride ion acceptor properties of OsO4 and OsO3F2 were investigated. The salts [N(CH3)4][OsO4F] and [N(CH3)4]2[OsO4F2] were prepared by the reactions of OsO4 with stoichiometric amounts of [N(CH3)4][F] in CH3CN solvent. The salts [N(CH3)4][OsO3F3] and [NO][OsO3F3] were prepared by the reactions of OsO3F2 with a stoichiometric amount of [N(CH3)4][F] in CH3CN solvent and with excess NOF, respectively. The OsO4F- anion was fully structurally characterized in the solid state by vibrational spectroscopy and by a single-crystal X-ray diffraction study of [N(CH3)4][OsO4F]: Abm2, a = 7.017(1) A, b = 11.401(2) A, c = 10.925(2) A, V = 874.1(3) A3, Z = 4, and R = 0.0282 at -50 degrees C. The cis-OsO4F2(2-) anion was characterized in the solid state by vibrational spectroscopy, and previous claims regarding the cis-OsO4F2(2-) anion are shown to be erroneous. The fac-OsO3F3- anion was fully structurally characterized in CH3CN solution by 19F NMR spectroscopy and in the solid state by vibrational spectroscopy of its N(CH3)4+ and NO+ salts and by a single-crystal X-ray diffraction study of [N(CH3)4][OsO3F3]: C2/c, a = 16.347(4) A, b = 13.475(3) A, c = 11.436(3) A, beta = 134.128(4) degrees, V = 1808.1(7) A3, Z = 8, and R = 0.0614 at -117 degrees C. The geometrical parameters and vibrational frequencies of OsO4F-, cis-OsO4F2(2-), monomeric OsO3F2, and fac-OsO3F3- and the fluoride affinities of OsO4 and monomeric OsO3F2 were calculated using density functional theory methods.
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Affiliation(s)
- M Gerken
- Department of Chemistry, McMaster University, Hamilton, Ontario L8S 4M1, Canada
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31
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Klauser RJ, Raake W, Meinetsberger E, Zeiller P. Antithrombotic and anticoagulant properties of synthetic polyanions: sulfated bis-aldonic acid amides. J Pharmacol Exp Ther 1991; 259:8-14. [PMID: 1656031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Fifteen polyanionic bis-aldonic acid amides were synthesized by condensation of the corresponding aldonic acids and alpha,omega-diamines and by subsequent sulfation of the intermediates. The compounds were completely sulfated and exhibited molecular weights between 1450 and 2600 daltons. The antithrombotic activity of these synthetic heparin analogs was evaluated in a rat jugular vein clamping induced thrombosis model. Several compounds pounds were potent antithrombotic substances comparable in potency to the low molecular weight heparin Fraxiparin. Some structure activity relationships on their pharmacologic action could be deduced. The antithrombotic activity of a representative agent was confirmed using the Wessler stasis model in rabbits. In the in vitro tests the bis-aldonic acid amides exhibited moderate to low anticoagulant effects depending on the assay used. In the activated partial thromboplastin time assay, the anticoagulant potency of these compounds was between 2- and 30-fold lower than that of heparin. The anti-factor Xa activity of the experimental substances was at least 50 times lower than that of heparin, whereas the compounds were devoid of anti-factor IIa activity when measured in an amidolytic assay. The anticoagulant effects of these agents were dependent on the length of the spacing and on the type of aldonic acid moieties. These bisaldonic acid amides represent a novel class of potent antithrombotic substances without any anti-factor IIa activities and only very low anti-factor Xa activities, suggesting that these antiprotease actions are not a prerequisite for the antithrombotic action of polyanionic substances.
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Affiliation(s)
- R J Klauser
- Luitpold-Werk, Chem.-Pharm. Fabrik, München, West Germany
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