Enantioselective Molecular Recognition of Chiral Organic Ammonium Ions and Amino Acids Using Cavitand-Salen-Based Receptors

2011 ◽  
Vol 2011 (28) ◽  
pp. 5674-5680 ◽  
Author(s):  
Maria E. Amato ◽  
Francesco P. Ballistreri ◽  
Salvatore D'Agata ◽  
Andrea Pappalardo ◽  
Gaetano A. Tomaselli ◽  
...  
Keyword(s):  
Amino Acids ◽  
Molecular Recognition ◽  
Ammonium Ions

scholarly journals Molecular recognition of organic ammonium ions in solution using synthetic receptors

2010 ◽  
Vol 6 ◽  
Author(s):  
Andreas Späth ◽  
Burkhard König
Keyword(s):  
Molecular Recognition ◽  
Hydrophobic Interactions ◽  
Covalent Bond ◽  
Ammonium Ion ◽  
Synthetic Receptors ◽  
Ammonium Ions ◽  
Wide Range ◽  
Covalent Bond Formation ◽  
Reversible Covalent ◽  
Ion Receptors

Ammonium ions are ubiquitous in chemistry and molecular biology. Considerable efforts have been undertaken to develop synthetic receptors for their selective molecular recognition. The type of host compounds for organic ammonium ion binding span a wide range from crown ethers to calixarenes to metal complexes. Typical intermolecular interactions are hydrogen bonds, electrostatic and cation–π interactions, hydrophobic interactions or reversible covalent bond formation. In this review we discuss the different classes of synthetic receptors for organic ammonium ion recognition and illustrate the scope and limitations of each class with selected examples from the recent literature. The molecular recognition of ammonium ions in amino acids is included and the enantioselective binding of chiral ammonium ions by synthetic receptors is also covered. In our conclusion we compare the strengths and weaknesses of the different types of ammonium ion receptors which may help to select the best approach for specific applications.

scholarly journals The attempt to explain the various reaktions of rape and corn plants on the nitrogen usee in the ammonium or nitrate forms

2013 ◽  
Vol 46 (1) ◽  
pp. 39-49
Author(s):  
Zofia Uziak ◽  
Edward Borowski ◽  
Zbyszek Blamowski
Keyword(s):  
Amino Acids ◽  
Biomass Yield ◽  
Organic N ◽  
Lower Content ◽  
Ammonium Ions ◽  
Total N ◽  
Similar Content ◽  
Free Ammonium ◽  
Corn Plants ◽  
N Fractions

The reaction of the rape and corn plants on the nitrogen applied in the form NO<sub>3</sub><sup>-</sup> or NH<sub>4</sub><sup>+</sup> was studied under the controlled conditions. The ammonium ions with rape markedly lowered the growth rate, the intensity of photosynthesis and biomass yield, with relation to the plants fertilized with nitrates. With corn the effect of both N-forms was similar and positive. The biomass of the rape using NH<sub>4</sub><sup>+</sup>, with relation to the plants fertilized with NO<sub>3</sub><sup>-</sup> showed lower content of total N, and protein N, as well as markedly higher content of amino-acids of primary protein synthesis and their amides and free ammonium ions. Yet, the corn utilizing N-NH<sub>4</sub><sup>+</sup> showed, as compared with the plants fertilized with NO<sub>3</sub><sup>-</sup>, higher content of all studied organic N fractions. with similar content of free ammonium ions. This paper presents the thesis that the cause of the growth inhibition of rape fertilized with ammonium is low, as compared with corn, assimilation of NH<sub>4</sub><sup>+</sup> ions drawn in the roots of this plant.

Mise en évidence d'une activité uréasique chez Streptococcus thermophilus

1988 ◽  
Vol 34 (6) ◽  
pp. 818-822 ◽  
Author(s):  
V. Juillard ◽  
M. J. Desmazeaud ◽  
H. E. Spinnler
Keyword(s):  
Amino Acids ◽  
Urease Activity ◽  
Culture Medium ◽  
Colorimetric Method ◽  
Streptococcus Thermophilus ◽  
Stationary Growth Phase ◽  
Optimal Temperature ◽  
Ammonium Ions ◽  
Stationary Growth ◽  
Optimal Ph

In Streptococcus thermophilus CNRZ 404, the presence of urease activity was demonstrated by means of a specific colorimetric method for ammonium ions. The main physicochemical properties of the enzyme were determined. The Km with urea as substrate was 1.19 mM and the optimal pH was approximately 7.5. Because both thermolability and enzyme activity increased as the temperature was increased to 70 °C, the optimal temperature could not be determined with precision. Urease activity was maximal at the beginning of the stationary growth phase; it was stimulated by the presence of urea and of certain amino acids such as arginine and glutamic acid in the culture medium. This activity has been detected in several other strains of Streptococcus thermophilus. [Translated by the journal]

scholarly journals Arthroderma tuberculatum and Arthroderma multifidum Isolated from Soils in Rook (Corvus frugilegus) Colonies as Producers of Keratinolytic Enzymes and Mineral Forms of N and S

2020 ◽  
Vol 17 (24) ◽  
pp. 9162
Author(s):  
Justyna Bohacz ◽  
Michał Możejko ◽  
Ignacy Kitowski
Keyword(s):  
Amino Acids ◽  
Culture Medium ◽  
Agricultural Practice ◽  
Ammonium Ions ◽  
Mineral N ◽  
Corvus Frugilegus ◽  
Keratinolytic Fungi ◽  
Sulfate Release ◽  
Proteins And Peptides

Keratinolytic fungi representing the genus Arthroderma that were isolated from the soils of a rook (Corvus frugilegus) colony were used as biological agents for the disposal of waste feathers. The aim of this study was to assess the abilities of Arthroderma tuberculatum and Arthroderma multifidum fungi with a varied inflow of keratin matter to biodegrade waste feathers. The evaluation was based on the determination of feather mass loss, the activity of keratinolytic enzymes, and the content of mineral N and S forms. It was found that the activity of protease released by the fungi contributed to an increase in the level of soluble proteins and peptides and the concentration of ammonium ions, as well as alkalization of the culture medium. Keratinase activity was significantly correlated with sulfate release, especially in A. tuberculatum cultures. The strains of A. tuberculatum fungi isolated from the soil with the highest supply of organic matter, i.e., strains III, IV, and V, had the lowest enzymatic activity, compared to the A. multifidum strains, but they released mineral nitrogen and sulfur forms that are highly important for fertilization, as well as nutritionally important peptides and amino acids. A. tuberculatum strains can be used for the management of waste feathers that can be applied in agricultural practice.

scholarly journals Data on recovery of 21 amino acids, 9 biogenic amines and ammonium ions after spiking four different beers with five concentrations of these analytes

Data in Brief ◽  
2016 ◽  
Vol 9 ◽  
pp. 398-400 ◽  
Author(s):  
Begoña Redruello ◽  
Victor Ladero ◽  
Beatriz del Rio ◽  
María Fernández ◽  
M. Cruz Martín ◽  
...  
Keyword(s):  
Amino Acids ◽  
Biogenic Amines ◽  
Ammonium Ions

Spontaneous action potentials in isolated guinea-pig cerebellar slices: effects of amino acids and conditions affecting sodium and water uptake

1973 ◽  
Vol 184 (1074) ◽  
pp. 83-90 ◽  
Keyword(s):  
Amino Acids ◽  
Guinea Pig ◽  
Action Potentials ◽  
Excitatory Amino Acids ◽  
Quantitative Assessment ◽  
Ammonium Ions ◽  
Quantitative Correlation ◽  
Spontaneous Action ◽  
Inhibitory Amino Acids ◽  
Spontaneous Action Potentials

The effects of incubation conditions on the frequency of spontaneous action potentials exhibited by guinea-pig cerebellar slices, and recorded with an extracellular microelectrode, have been investigated. Various incubation conditions that lead to tetrodotoxin-sensitive uptakes of water and of sodium ions by the incubated cerebellar slices lead to enhanced frequencies of the spontaneous action potentials, e. g. the presence of protoveratrine or of ouabain, the absence of glucose or the onset of anoxia. The frequency of the spikes is also enhanced by acetylcholine (in presence of neostigmine) or by the presence of excitatory amino acids, such as L-glutamate, D-glutamate or L-aspartate. It is suppressed by tetrodotoxin, or by the inhibitory amino acids, e. g. γ -aminobutyrate, glycine or taurine, or by ammonium ions or by pentobarbital. It is concluded that guinea-pig cerebellar slices, incubated under specified conditions, may provide a suitable means for quantitative correlation of neurochemical data with data obtained by electrophysiological techniques in tissue incubated under similar conditions and also for quantitative assessment of the effects of amino acids on cerebellar electrical activity.

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