نتایج جستجو برای: primary amide
تعداد نتایج: 655059 فیلتر نتایج به سال:
Bis(triazole)benzamide 1 has been readily synthesized by means of Cu-catalyzed 1,3-dipolar cycloaddition and its ability to bind halide anions and neutral gallic acid derivative 12GA has been theoretically and experimentally investigated. The cavity defined by the N-H amide group and the vicinal aromatic hydrogens is suitable to form H-bonding arrays with halide guests. The stability of complex...
Raman spectra of native and solubilized feather keratin have been obtained, and the amide I and amide 111 regions have been analyzed by band resolution techniques. The amide I region of the native form indicates that at least 64% of the protein has an antiparallel chain pleated sheet structure, the remainder being unordered. For the solubilized keratin all of the protein is in an unordered stat...
Amide-iminol tautomerism was studied for ionized oxamic acid (OA+•) in the gas phase using theDFT method with the UB3LYP functional and various basis sets {6-31++G(d,p), 6-311+G(d,p), and augcc-pVDZ}. Among twenty tautomers-rotamers possible for OA+•, eleven isomers were found to bethermodynamically stable. Similarly as for the neutral molecule, ionization (OA → OA+• + e) favors theamidization ...
BACKGROUND Fourier Transform Infrared Imaging (FTIRI) is used to investigate the amide anisotropies at different surfaces of a three-dimensional cartilage or tendon block. With the change in the polarization state of the incident infrared light, the resulting anisotropic behavior of the tissue structure is described here. METHODS Thin sections (6 mum thick) were obtained from three different ...
Biopolymers such as DNA store information in their chains using controlled sequences of monomers. Here we describe a non-natural information-containing macromolecule that can store and retrieve digital information. Monodisperse sequence-encoded poly(alkoxyamine amide)s were synthesized using an iterative strategy employing two chemoselective steps: the reaction of a primary amine with an acid a...
The biosynthesis of aminocoumarin antibiotics involves the action of amide synthetases which construct amide bonds between aminocoumarins and various acyl moieties. Libraries of aminocoumarin analogues have been generated by in vivo fermentation, via feeding known amide synthetase substrates into producing microbial strains. Critically, such feeding studies rely on the inherent or engineered su...
Amide bond formation reactions are among the most important transformations in organic chemistry because of the widespread occurrence of amides in pharmaceuticals, natural products and biologically active compounds. The Beckmann rearrangement is a well-known method to generate secondary amides from ketoximes. However, under the acidic conditions commonly employed, aldoximes RHC=NOH rarely rearr...
Cleavage of the C-N bond of carboxamides generally requires harsh conditions. This study reveals that tris(amido)Al(III) catalysts, such as Al2(NMe2)6, promote facile equilibrium-controlled transamidation of tertiary carboxamides with secondary amines. The mechanism of these reactions was investigated by kinetic, spectroscopic, and density functional theory (DFT) computational methods. The cata...
Aromatic amine dehydrogenase uses a tryptophan tryptophylquinone (TTQ) cofactor to oxidatively deaminate primary aromatic amines. In the reductive half-reaction, a proton is transferred from the substrate C1 to betaAsp-128 O-2, in a reaction that proceeds by H-tunneling. Using solution studies, kinetic crystallography, and computational simulation we show that the mechanism of oxidation of arom...
A &*-activated enzyme derived from the soluble fraction of guinea pig liver, and designated transglutaminase by Waelsch et al. (2-4) catalyzes the incorporation of a number of primary amines into certain proteins and polypeptides. There is evidence that this reaction proceeds via the replacement of amide groups of glutamine residues only (4, 5). Transglutaminase also catalyzes the release of am...
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