Search results for "ACYLATION"
showing 10 items of 87 documents
Regio-specific synthesis of new 1-(tert-butyl)-1H-pyrazolecarboxamide derivatives
2017
Regio-specific and non-regiospecific condensation reactions on 1,3-dicarbonyl compounds rendered 1,3,5-trisubstituted pyrazoles. Herein, the control of regio-specificity was a significant improvement in pyrazole research. A high yield acylation of poorly nucleophilic aryl amines, which resulted in mono- or diacylated products depending on the reaction conditions, is described. As a result, a library of potentially bioactive compounds was obtained. Fil: Ruatta Merke, Santiago Matías. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas; Argentina Fil: Murguia, Marcelo Cesar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Co…
A bi-allelic loss-of-function SARS1 variant in children with neurodevelopmental delay, deafness, cardiomyopathy, and decompensation during fever
2021
Aminoacyl-tRNA synthetases (aaRS) are ubiquitously expressed enzymes responsible for ligating amino acids to their cognate tRNA molecules through an aminoacylation reaction. The resulting aminoacyl-tRNA is delivered to ribosome elongation factors to participate in protein synthesis. Seryl-tRNA synthetase (SARS1) is one of the cytosolic aaRSs and catalyzes serine attachment to tRNASer . SARS1 deficiency has already been associated with moderate intellectual disability, ataxia, muscle weakness, and seizure in one family. We describe here a new clinical presentation including developmental delay, central deafness, cardiomyopathy, and metabolic decompensation during fever leading to death, in a…
Solution versus Fluorous versus Solid-Phase Synthesis of 2,5-Disubstituted 1,3-Azoles. Preliminary Antibacterial Activity Studies
2009
A small library of compounds with an oxa(thia)zole scaffold and structural diversity in both positions 2 and 5 has been synthesized. Double acylation of a protected glycine affords intermediate α-amido-β-ketoesters, which in turn can be dehydrated to afford 1,3-oxazoles or reacted with Lawesson’s reagent to furnish 1,3-thiazoles. This procedure was designed with its adaptation to fluorous techniques in mind. Thus, when a protected glycine with a fluorous tag in the ester moiety is used as a starting material, the synthesis can be easily completed without column chromatography purification of intermediate compounds with good to excellent yields, thus affording a suitable entry to the prepara…
Preparation of dopaminergic N-alkyl-benzyltetrahydroisoquinolines using a 'one-pot' procedure in acid medium.
2000
The preparation of N-methyl-BTHIQ (4) from N-phenylethyl-phenacetamide (1) by cyclization, reduction and N-alkylation in acid medium has been achieved in good yield in a 'one-pot' procedure. Acylation of imine (2) intermediate afforded the Z and E stereoselectivity in the enamide formation. 6-Hydroxy-BTHIQ (7) shows selectivity for D2 dopamine receptors, while its N-methylated homologue (8) displays higher affinities for both D1 and D2 receptor types, with an unexpected increase in D1 dopamine receptor affinity.
Supramolecular structures formed by calix[8]arene derivatives.
2003
Octamethoxy calix[8]arenes substituted in the para position by amide, urea, and imide functions were synthesized from the octamethyl ether of tert-butylcalix[8]arene by ipso nitration, reduction, and acylation. Scanning force microscopy of spin coated samples on graphite suggests that these derivatives self-organize into tubular nanorods via hydrogen bonds between p-amide functions. A single-crystal X-ray structure reveals a centrosymmetric conformation for the octanitro derivative. [structure: see text]
Supramolecular PEG-co-oligo(p-benzamide)s prepared on a peptide synthesizer.
2007
An automated synthesis protocol has been developed for the preparation of oligo(p-benzamide)s on solid support using a commercial peptide synthesizer employing a variation of standard Fmoc chemistry. Bis(trichloromethyl carbonate) in NMP was used to activate the aromatic carboxylic acids for acylation of secondary aromatic amines on solid support. N-Protected hepta(p-benzamide) was automatically prepared on solid support and manually converted to a solid supported block co-oligomer by attaching a poly(ethylene glycol) chain. Cleavage from the support could be achieved with minimal loss of the p-methoxybenzyl N-protective group. While the N-protected block co-oligomer was molecularly dissolv…
Partialsynthese neuer Ergolinderivate aus Clavinalkaloiden, 2. Mitt.1) O-Acyl-8-hydroxymethyl-6-methylergol-8-ene und -ergol-9-ene
1983
Die Titelverbindungen sind durch Acylierung von Elymoclavin (1) bzw. Lysergol (2) mit Saurechloriden, im Fall der Ester von 2 auch durch Isomerisierung von O-Acyl-1 mit aktiviertem Al2O3 darstellbar. Umgekehrt fuhrt die Acylierung von 2 in bestimmten Fallen spontan zur Bildung eines Gemisches der O-Acylderivate von 1 und 2.. Partial Synthesis of New Ergoline Derivatives from Clavine Alkaloids, II: O-Acyl-8-(hydroxymethyl)-6-methylergol-8-enes and -ergol9-enes The title compounds can be prepared by acylation of elymoclavine (1) and lysergole (2), respectively, with acid chlorides or, in the case of the esters of 2, by isomerization of O-acyl-1 with activated Al2,O3. On the other hand, in cer…
Isolation of a Putative Hydroxyacyl Enzyme Intermediate of an Epoxide Hydrolase
1994
A putative covalent, alpha-hydroxyacyl intermediate was isolated by the brief exposure of murine soluble epoxide hydrolase to its substrate. The reaction was reversed by time and blocked by competitive inhibitors. The formation of the intermediate was dependent upon the concentration of the enzyme and was increased by incubation under acidic conditions. The structure of the intermediate was supported by microchemical methods.
Binding of Escherichia coli hemolysin and activation of the target cells is not receptor-dependent.
2005
Abstract Production of a single cysteine substitution mutant, S177C, allowed Escherichia coli hemolysin (HlyA) to be radioactively labeled with tritiated N-ethylmaleimide without affecting biological activity. It thus became possible to study the binding characteristics of HlyA as well as of toxin mutants in which one or both acylation sites were deleted. All toxins bound to erythrocytes and granulocytes in a nonsaturable manner. Only wild-type toxin and the lytic monoacylated mutant stimulated production of superoxide anions in granulocytes. An oxidative burst coincided with elevation of intracellular Ca2+, which was likely because of passive influx of Ca2+ through the toxin pores. Competi…
Short syntheses of (+)-ferruginol from (+)-dehydroabietylamine
2012
Short syntheses of bioactive (+)-ferruginol in five or six synthetic steps starting from commercially available (+)-dehydroabietylamine are described. The oxygenated function at C12 was introduced via a Friedel–Crafts acylation of N-phthaloyldehydroabietylamine followed by Baeyer–Villiger oxidation. Then, overall deprotection of functional groups, reductive deamination or biomimetic oxidative deamination, and final Wolff–Kishner reduction provided (+)-ferruginol in 21 and 23% overall yields, respectively.