- On the Use of Hydrophobic Probes in the Chromatographic Purification of Solid-phase-synthesized Peptides
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A strategy for the reversed-phase chromatographic purification of solid-phase-synthesized peptides is described and illustrated by the synthesis of a 23-mer model peptide; the target peptide is distinguished from terminated by-products by the attachment of a hydrophobic probe to the resin-bound peptide.
- Garcia-Echeverria, Carlos
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- Vinyl Sulfonates: A Click Function for Coupling-and-Decoupling Chemistry and their Applications
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The term coupling-and-decoupling (CAD) chemistry refers to applications in which efficient bond formation and subsequent cleavage between two moieties is required. Within this context, the scope of the vinyl sulfonate (VSO) group as an efficient tool for CAD chemistry is reported. The coupling step relies on the click features of the Michael-type addition of diverse nucleophiles to vinyl sulfonates as a valuable methodology. The feasibility of this strategy has been proved by the high yields obtained in mild conditions with model VSO derivatives. Cleavage of the resulting sulfonate adducts either through nucleophilic substitution with different nucleophiles (for alkyl VSO groups) or through hydrolysis (for both alkyl and aryl VSO) are successful strategies for the decoupling step, the former being the most promising, as the reaction proceeds under milder conditions with thiol nucleophiles. Moreover, the click VSO coupling chemistry proves to be orthogonal with the click CuAAC reaction, which enables the VSO-CAD methodology for the preparation of hetero-bifunctional clickable and cleavable linkers for double click modular strategies. The potential of the VSO-CAD chemistry is demonstrated in two biologically relevant examples: the decoupling of sulfonates with glutathione (GSH) under conditions compatible with those of living systems; and the synthesis of homo- and heterogeneous multivalent glycosylated systems from 1-thio and 1-azido or 1-azidoethyl sugar derivatives and bis-vinyl sulfonates (homo systems) or alkynyl-VSO bifunctional clickable-cleavable linkers (hetero systems). As proof of concept, the cleavable character of these multivalent systems was demonstrated by using one of them as a reversible linker for the non-covalent assembling and chemical decoupling of two model lectins. (Figure presented.).
- Cruz, Carlos M.,Ortega-Mu?oz, Mariano,López-Jaramillo, F. Javier,Hernández-Mateo, Fernando,Blanco, Victor,Santoyo-González, Francisco
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p. 3394 - 3413
(2016/11/13)
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- Sulfur makes the difference: Synthesis and mesomorphic properties of novel thioether-functionalized imidazolium ionic liquid crystals
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Novel thioether-linked imidazolium ionic liquid crystals were synthesized starting from methyl 2-mercaptoacetate. The mesomorphic properties were determined by differential scanning calorimetry (DSC), polarizing optical microscopy (POM), and X-ray diffraction. All mesogens displayed smectic A mesophase geometries with strongly interdigitated bilayer structures. Comparison of the thioether-linked imidazolium salts with the corresponding amine- and amide-linked imidazolium salts as well as simple N-alkyl-imidazolium salts showed that both mesophase width and stability increased with increasing softness of the linking unit, thus indicating the beneficial effect of sulfur. Additionally, an increase of the length of the linking unit decreased the interdigitation of the alkyl chains.
- Mansueto, Markus,Kre?, Katharina Christina,Laschat, Sabine
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p. 6258 - 6264
(2015/03/30)
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- Method of treating hepatitis virus infections
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A method of treating hepatitis virus infection is disclosed. The method comprising administering to a human subject in need of such treatment an effective hepatitis virus-combatting amount of an alkyl lipid or alkyl lipid derivative.
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- In Vitro Evaluation of Phosphocholine and Quaternary Ammonium Containing Lipids as Novel Anti-HIV Agents
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A series of synthetic lipids containing a two- or three-carbon backbone substituted with a thio, oxy, or amidoalkyl functionality and either a phosphocholine or quaternary ammonium moiety was evaluated as potential anti-HIV-1 agents.Several analogues were identified as possessing activity with the most promising compound being rac-3-octadecanamido-2-ethoxypropylphosphocholine (8).Compound 8 exhibited an IC50 for the inhibition of plaque formation of 0.16 μM wich was 84-fold lower than the IC50 value determined for CEM-SS cell growth inhibition.Initial mechanistic studies have indicated that these compounds, unlike AZT, are not reverse transcriptase (RT) inhibitors, but instead appear to inhibit a late step in HIV replication involving virus assembly and infectious virus production.Since these lipids are acting via a different mechanism, they represent an alternative approach to the chemotherapeutic treatment of AIDS as well as candidates for combination therapy with AZT.
- Meyer, Karen L.,Marasco, Canio J.,Morris-Natschke, Susan L.,Ishaq, Khalid S.,Piantadosi, Claude,Kucera, Louis S.
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p. 1377 - 1383
(2007/10/02)
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