- Novel chemoselective 18F-radiolabeling of thiol-containing biomolecules under mild aqueous conditions
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We report a novel prosthetic group based on a heterocyclic methylsulfone derivative for the rapid, stable, and chemoselective 18F-labeling of thiol-containing (bio)molecules under mild aqueous reaction conditions. Compared to established maleimide approaches, the new methodology displays some clear advantages for imaging probe development.
- Chiotellis, Aristeidis,Sladojevich, Filippo,Mu, Linjing,Müller Herde, Adrienne,Valverde, Ibai E.,Tolmachev, Vladimir,Schibli, Roger,Ametamey, Simon M.,Mindt, Thomas L.
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- A general concept for the introduction of hydroxamic acids into polymers
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Hydroxamic acids (HA) form stable complexes with a large variety of metal-ions, affording hydroxamates with high complexation constants. Hydroxamic acid moieties play a crucial role in the natural iron metabolism. In this work, 1,4,2-dioxazoles linked to a hydroxyl group are introduced as key compounds for the installation of hydroxamic acids at synthetic polymers in well-defined positions. A general synthetic scheme is developed that gives access to a series of novel functional key building blocks that can be universally used to obtain hydroxamic acid-based monomers and polymers, for instance as protected HA-functional initiators or for the synthesis of a variety of novel HA-based monomers, such as epoxides or methacrylates. To demonstrate the excellent stability of the dioxazole-protected hydroxamic acids, direct incorporation of the dioxazole-protected hydroxamic acids into polyethers is demonstrated via oxyanionic polymerization. Convenient subsequent deprotection is feasible under mild acidic conditions. α-Functional HA-polyethers, i.e. poly ethylene glycol, polypropylene glycol and polyglycerol based on ethylene oxide, propylene oxide and ethoxy ethyl glycidyl ether, respectively are prepared with low dispersities (-1. Water-soluble hydroxamic acid functional poly(ethylene glycol) (HA-PEG) is explored for a variety of biomedical applications and surface coating. Complexation of Fe(iii) ions, coating of various metal surfaces, enabling e.g., solubilization of FeOx nanoparticles by HA-PEGs, are presented. No impact of the polyether chain on the chelation properties was observed, while significantly lower anti-proliferative effects were observed than for deferoxamine. HA-PEGs show the same complexation behavior as their low molecular weight counterparts. Hydroxamic acid functional polymers are proposed as an oxidatively stable alternative to the highly established catechol-based systems.
- Johann, Tobias,Keth, Jennifer,Bros, Matthias,Frey, Holger
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- Electro-Oxidative Selective Esterification of Methylarenes and Benzaldehydes
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A mild and green electro-oxidative protocol to construct aromatic esters from methylarenes and alcohols is herein reported. Importantly, the reaction is free of metals, chemical oxidants, bases, acids, and operates at room temperature. Moreover, the design of the electrolyte was found critical for the oxidation state and structure of the coupling products, a rarely documented effect. This electro-oxidative coupling process also displays exceptional tolerance of many fragile easily oxidized functional groups such as hydroxy, aldehyde, olefin, alkyne, as well as neighboring benzylic positions. The enantiomeric enrichment of some chiral alcohols is moreover preserved during this electro-oxidative coupling reaction, making it overall a promising synthetic tool.
- Yu, Congjun,?zkaya, Bünyamin,Patureau, Frederic W.
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supporting information
p. 3682 - 3687
(2021/02/01)
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- Chemoselective and Metal-Free Synthesis of Aryl Esters from the Corresponding Benzylic Alcohols in Aqueous Medium Using TBHP/TBAI as an Efficient Catalytic System
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A novel and transition-metal-free strategy has been developed for the synthesis of aryl esters starting from corresponding benzylic primary alcohols as the exclusive substrates using tert -butyl hydroperoxide (TBHP) as a terminal oxidant in the presence of catalytic amount of tetrabutylammonium iodide (TBAI) and imidazole, where the aliphatic alcohols remained unaffected. These reactions are highly chemoselective and associated with high yield and wide applicability accommodating a wide range of substituents. Excellent chemoselectivity has also been demonstrated through intramolecular competition experiments. This protocol can be considered as an important analogue of Tishchenko reaction using benzylic alcohols as the substrates instead of benzaldehydes.
- Nandy, Sneha,Ghatak, Avishek,Das, Asit Kumar,Bhar, Sanjay
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p. 2208 - 2212
(2018/10/02)
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- COMPOSITIONS, METHODS, AND SYSTEMS FOR THE SYNTHESIS AND USE OF IMAGING AGENTS
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The present invention provides compounds with imaging moieties for imaging a subject. The present invention also relates to systems, compositions, and methods for the synthesis and use of imaging agents, or precursors thereof. An imaging agent precursor may be converted to an imaging agent using the methods described herein. In some cases, a composition or plurality of imaging agents is enriched in 18 F. In some cases, an imaging agent may be used to image an area of interest in a subject, including, but not limited to, the heart, cardiovascular system, cardiac vessels, brain, and other organs.
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Paragraph 1426
(2015/07/22)
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- Contrast agent and for the use of a synthetic composition, method and system (by machine translation)
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The present invention provides compounds with imaging moieties for imaging a subject. The present invention also relates to systems, compositions, and methods for the synthesis and use of imaging agents, or precursors thereof. An imaging agent precursor may be converted to an imaging agent using the methods described herein. In some cases, a composition or plurality of imaging agents is enriched in 18 F. In some cases, an imaging agent may be used to image an area of interest in a subject, including, but not limited to, the heart, cardiovascular system, cardiac vessels, brain, and other organs.
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Paragraph 0584
(2016/10/07)
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- Efficient simultaneous emission from RGB-emitting organoboron dyes incorporated into organic-inorganic hybrids and preparation of white light-emitting materials
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In order to investigate dye-dispersion behaviors in organic-inorganic hybrids, we incorporated RGB light-emitting organoboron dyes (1,3-diketonate BF2 complex, borondipyrromethene (BODIPY), and boron di(iso)indomethene as blue, green and red light-emitting dyes, respectively) into poly(2-hydroxyethyl methacylate) (PHEMA)-silica hybrids prepared by the microwave-assisted technique. Photoluminescence spectra of two dyes in various concentrations and Stern-Volmer plots indicate that the energy transfer efficiencies between the dyes in the hybrids were lower than that in the solution state, resulting from the suppression of concentration-quenching. Furthermore, we demonstrate the color tuning for preparing white light-emitting hybrids based on simultaneous RGB light-emission of the organoboron dyes. Finally, pure white light-emitting hybrids were obtained by the microwave-assisted in situ method.
- Kajiwara, Yuichi,Nagai, Atsushi,Tanaka, Kazuo,Chujo, Yoshiki
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p. 4437 - 4444
(2013/07/26)
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- PYRROLIDINE DERIVATIVES AS HISTAMINE H3 RECEPTOR ANTAGONISTS
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The present invention discloses novel compounds of Formula (I) or pharmaceutically acceptable salts thereof which have histamine-H3 receptor antagonist or inverse agonist activity, as well as methods and intermediates for preparing such compounds. In another embodiment, the invention discloses pharmaceutical compositions comprising compounds of Formula (I) as well as methods of using them to treat obesity, cognitive deficiencies, narcolepsy, and other histamine H3 receptor-related diseases.
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Page/Page column 30
(2008/06/13)
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- Poly(ε-caprolactone) macroligands with β-diketonate binding sites: Synthesis and coordination chemistry
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Dibenzoylmethane (dbm) initiators with one and two alcohol sites were used to generate dbm end-functionalized and dbm-centered poly(ε-caprolactone) macroligands (dbmPCL and dbmPCL2) with low polydispersities (~1.1). Chelation of polymeric ligands to metal ions (Eu3+, Fe3+, Ni2+ and Cu2+) produced metal-centered star polymers, which were characterized by UV-vis and fluorescence spectroscopy, as well as gel permeation chromatography.
- Bender, Jessica L.,Shen, Qun-Dong,Fraser, Cassandra L.
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p. 7277 - 7285
(2007/10/03)
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- Synthesis and preliminary use of novel acrylic ester-derived task-specific ionic liquids
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Novel electrophilic alkenes bearing an ionic liquid-type appendage have been prepared and used in Diels-Alder cycloadditions, 1,4-additions, Heck couplings and Stetter reactions; this new type of support allows easy monitoring of the reactions by NMR and MS as well as simple and efficient work-up and isolation procedures.
- Anjaiah, Siddam,Chandrasekhar, Srivari,Grée, René
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p. 569 - 571
(2007/10/03)
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- Radiosynthesis of (±)-(2-((4-(2-[18F]fluoroethoxy)phenyl)bis(4-methoxy- phenyl) methoxy)ethylpiperidine-3-carboxylic acid: A potential GAT-3 PET ligand to study GABAergic neuro-transmission in vivo
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A dysfunction of GABAergic neurotransmission is related to diseases such as epilepsy, Huntington-disease and Parkinson-syndrome. A new 18F-fluorine labelled GABA transporter ligand for the GABA-transporter subtype GAT-3 was developed which may allow the in vivo visualisation of GABAergic neurotransmission. The precursors ethyl (2-(4-hydroxyphenyl)bis (4-methoxyphenyl)-methoxy)ethyl)-piperidine-3-carboxylate and ethyl(2-((4-(2-tosylethoxy)phenyl)-bis(4-methoxyphenyl)-methoxy) ethyl)piperidine-3-carboxylate were synthesised and labelled by the use of 2-[18F]fluoroethyltosylate or [18F]fluoride. Subsequent cleavage of the ester moiety gave the final product (±)-(2-((4-(2-[18F]fluoroethoxy)phenyl)bis(4-methoxy- phenyl)methoxy)ethyl)-piperidine-3-carboxylic acid in a decay corrected yield of 33-36%. Preliminary biodistribution kinetics were determined with BALB/c mice ex vivo for brain, liver, kidney, spleen, blood and bone. (2-((4-(2-[18F]fluoroethoxy)-phenyl)bis(4-methoxyphenyl)methoxy)- ethyl) piperidine-3-carboxylic acid showed a maximum brain uptake after 1 h p.i. of about 0.3% ID/g. Copyright
- Schirrmacher, Ralf,Hamkens, Wilhelm,Piel, Markus,Schmitt, Ulrich,Lddens, Hartmut,Hiemke, Christoph,Rsch, Frank
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p. 627 - 642
(2007/10/03)
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