نتایج جستجو برای: mixed amines
تعداد نتایج: 240806 فیلتر نتایج به سال:
Problem statement: Biogenic amines are basic nitrogenous compounds present in a wide variety of foods and beverages. Their formations were mainly due to the amino acids decarboxylase activity of certain microorganisms. Excessive intake of biogenic amines could induce many undesirable physiological effects determined by their psychoactive and vasoactive action. Fish sauce which is considered as ...
An automated trihydroxyindoleprocedure for the differential estimation of epinephrine and norepinephrinein tissues,urine, and blood is presented in detail. After an initial purification of the catecholaminesby adsorption on aluminum oxide, the neutralized eluates are subjected to automatic analysis, in which potassiumferricyanide and an alkaline stabilizing agent are automatically mixed sequent...
We describe a comprehensive gas chromatographic analysis for therapeutic concentrations of amitriptyline, nortriptyline, imipramine, desipramine, doxepin, and desmethyldoxepin in plasma, with use of a nitrogen detector. All these drugs are extracted and chromatographed under identical conditions. Each tertiary amine tricyclic is well resolved from its secondary amine metabolite on a mixed-phase...
A novel method for the mono-N-alkylation of primary amines, diamines, and polyamines was developed using cesium bases in order to prepare secondary amines efficiently. A cesium base not only promoted alkylation of primary amines but also suppressed overalkylations of the produced secondary amines. Various amines, alkyl bromides, and alkyl sulfonates were examined, and the results demonstrated t...
A ligand free, copper-catalyzed N-arylation reaction of amines with diheteroaryl halides in heterogeneous medium at room temperature has been developed. The protocol is very effective for low boiling amines and useful for amines available in aqueous solution. The reaction gives chemospecific arylation of amines with diheteroaryl halides in the mixture monoheteroaryl halides, diheteroaryl halide...
Separation of some biogenic amines via RP-HPLC using mixed micellar mobile phase was investigated. The compounds were derivatized before hand by dansyl chloride as a chromophoric reagent. Appropriate conditions for separation, were determined by studying factors such as temperature, type and percentage of organic modifier, concentration of surfactants (SDS and Brij-35) and the pH of the mobile ...
Lithiation of carbamates followed by borylation provides a powerful method for the homologation of boron reagents. However, when applied to hindered systems (secondary carbamates with tBu-boronic esters) for the construction of two quaternary centers, this methodology fails. Instead, using mixed boranes (tBuBMe2), the synthesis of adjacent quaternary stereogenic centers with full stereocontrol ...
Reversible phosphorylation is the major mechanism underlying the short-term hormonal control of phenylalanine hydroxylase activity in the liver. We report here, for the first time, the impact of a range of hormonal effectors on both the phosphorylation state and enzymic activity of phenylalanine hydroxylase present in isolated rat proximal kidney tubules. The most potent stimulator of enzyme ph...
Semicarbazide-sensitive amine oxidase (SSAO) is a copper-containing enzyme that catalyzes the oxidative deamination of endogenous and exogenous primary amines. SSAO exists in mammals both as a plasma-soluble and as a membrane-bound form, and its active site is able to come into contact with numerous xenobiotic, amine-containing compounds. The kinetic studies performed in this work showed that c...
Both long chain alkyl thiols and alkyl amines behave as size focusing agents for gold nanoparticles, a process that is under thermodynamic control. However, amines do not oxidize surface gold atoms while thiols do oxidize surface gold to gold(I) with evolution of hydrogen gas. Therefore, alkyl amines participate in digestive ripening by a different mechanism. The efficiency of alkyl amines for ...
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