Stereoselectivity of montmorillonite in the adsorption and deamination of some amino acids

AbstractOptical isomers deamination of L- and D-glutamic and aspartic amino acids and of their DL racemic mixtures has been achieved in the presence of Na-montmorillonite at pH = 6 and room temperature. The adsorption curves showed that the enantiomer adsorbed depends on the type of amino acid. Nevertheless, deamination reaction kinetics brought about a stereoselectivity of the clay mineral for the L-isomer and implicitly showed an unquestionable “structural chirality character” of the clay mineral.

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Self-Assembling Functionalized Amino Acids into Unusual Shapes

MRS Proceedings ◽

10.1557/opl.2011.129 ◽

2011 ◽

Vol 1312 ◽

Author(s):

Justin R. Barone ◽

Naresh K. Budhavaram ◽

Katherine J. Harvey

Keyword(s):

Amino Acids ◽

Hydrogen Bond ◽

Amino Acid ◽

Room Temperature ◽

Vinyl Sulfone ◽

Ethyl Vinyl ◽

Simple Route ◽

Self Assembling ◽

Component Systems ◽

Functionalized Amino Acids

ABSTRACTMulti-component small molecule systems that are amphiphilic or that can hydrogen bond end-to-end or side-to-side have been shown to self-assemble into a variety of shapes including fibers, rods, sheets, plates, spheres, and tubes. Recently, we have identified a simple route to self-assemble the same shapes from one-component systems. The structures form by attaching ethyl vinyl sulfone (EVS) to amino acids in water at room temperature. Choice of amino acid, amount of EVS substitution, and solvent conditions determine the final shape. Functionalized amino acids spontaneously form structures like fibers, spheres, tubes, and donuts when dried from solution. Here we focus on fibers and tubes.

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Amino Acid Catalyzed Conjugate Addition of Thiol to Dienone

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.834-836.450 ◽

2013 ◽

Vol 834-836 ◽

pp. 450-453

Author(s):

Han Feng Cui ◽

Yan Lin ◽

Hao Fan ◽

Li De Yu ◽

Ping Nan Wan

Keyword(s):

Amino Acids ◽

Amino Acid ◽

Room Temperature ◽

Addition Product ◽

Conjugate Addition ◽

Acid Catalyzed

Double conjugate addition of thiols with dienones was catalyzed by amino acids at room temperature in methanol, to afford the corresponding addition product in good to excellent yields.

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A Study of 2,4,6-Trinitrobenzenesulfonic Acid for Automated Amino Acid Chromatography

Clinical Chemistry ◽

10.1093/clinchem/14.10.967 ◽

1968 ◽

Vol 14 (10) ◽

pp. 967-978 ◽

Cited By ~ 21

Author(s):

Harold H Brown

Keyword(s):

Amino Acids ◽

Amino Acid ◽

Room Temperature ◽

Lower Sensitivity ◽

Static System ◽

Optimum Conditions ◽

Trinitrobenzenesulfonic Acid ◽

Imino Acid ◽

Major Disadvantage ◽

Heating Bath

Abstract The reaction of 2,4,6-trinitrobenzenesulfonic acid (TNBS) with amino acids was investigated by a static system to develop optimum conditions for application to automated amino acid chromatography. TNBS was found to be a very simple and sensitive reagent, easier to use than ninhydrin. The reaction occurs quite rapidly at room temperature, eliminating the requirement of a heating bath. The major disadvantage is a much lower sensitivity to the imino acid proline than to the amino acids.

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Inhibition of sickling in erythrocytes by amino acids

Blood ◽

10.1182/blood.v45.1.45.45 ◽

1975 ◽

Vol 45 (1) ◽

pp. 45-48 ◽

Cited By ~ 23

Author(s):

NM Rumen

Keyword(s):

Amino Acids ◽

Amino Acid ◽

Room Temperature

Abstract Sickling of erythrocytes was rapidly and quantitatively inhibited at room temperature by 3.8 mM homoserine, asparagine, and glutamine but by no other amino acid.

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Optical, dielectric & ferroelectric studies on amino acids doped TGS single crystals

RSC Advances ◽

10.1039/c5ra25700j ◽

2016 ◽

Vol 6 (40) ◽

pp. 33686-33694 ◽

Cited By ~ 26

Author(s):

P. R. Deepthi ◽

J. Shanthi

Keyword(s):

Amino Acids ◽

Amino Acid ◽

Single Crystals ◽

Room Temperature ◽

Solution Growth ◽

Slow Evaporation ◽

Growth Technique ◽

Optical Dielectric ◽

Solution Growth Technique

Pure TGS and amino acid (l-arginine, l-histidine and l-alanine) doped TGS crystals were grown by a slow evaporation solution growth technique at room temperature.

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N-Methylamino acids in peptide synthesis. V. The synthesis of N-tert-butyloxycarbonyl, N-methylamino acids by N-methylation

Canadian Journal of Chemistry ◽

10.1139/v77-125 ◽

1977 ◽

Vol 55 (5) ◽

pp. 906-910 ◽

Cited By ~ 112

Author(s):

S. T. Cheung ◽

N. Leo Benoiton

Keyword(s):

Amino Acids ◽

Amino Acid ◽

Methyl Iodide ◽

Peptide Synthesis ◽

Room Temperature ◽

Sodium Hydride ◽

Amino Acid Derivatives ◽

Enantiomerically Pure ◽

Neutral Amino Acids ◽

Related Data

The preparation of enantiomerically pure N-tert-butyloxycarbonyl,N-methylamino acids by N-methylation of the parent amino acid derivatives using sodium hydride and methyl iodide in tetrahydrofuran at room temperature is described for neutral amino acids including O-benzyl-protected threonine and tyrosine. Methylation of the O-benzylserine derivative under these conditions gives the N-methyldehydroalanine derivative. The β-elimination is completely suppressed, giving the corresponding N-methylserine derivative when the reaction is carried out at 5 °C. Other related data on N-methylation and N-methylamino acid derivatives are presented.

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Capillary Gas Chromatographic Analysis of Amino Acids by Enantiomer Labeling

Journal of AOAC INTERNATIONAL ◽

10.1093/jaoac/70.2.234 ◽

1987 ◽

Vol 70 (2) ◽

pp. 234-240

Author(s):

Ernst Bayer ◽

Hartmut Frank ◽

Jürgen Gerhardt ◽

Graeme Nicholson

Keyword(s):

Amino Acids ◽

Amino Acid ◽

Sea Water ◽

Biological Fluids ◽

Chemical Properties ◽

Internal Standard ◽

Optical Isomers ◽

Internal Standards ◽

Sample Enrichment ◽

Physical And Chemical

Abstract The optical isomers of amino acids can be easily separated by gas chromatography using capillary columns coated with the chiral polysiloxane peptide, Chirasil-Val. Quantitative trace amino acid analysis in complex mixtures such as biological fluids, sea water, or protein hydrolysates can be achieved by enantiomer labeling: The D-amino acid enantiomers, which do not occur naturally, are added to the sample prior to analysis as internal standards. Because the D-enantiomers show the same physical and chemical properties as the natural L-enantiomers, they are ideal standard references. In routine analysis, the derivatization is achieved with a new automated derivatization robot. The D-standard serves as overall internal standard for the whole analytical procedure from sample enrichment to derivatization, chromatography, and response of the detector.

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Stability of Famotidine in Minibags Refrigerated and/or Frozen in Total Parenteral Nutrition Solutions

DICP ◽

10.1177/1060028089023s1008 ◽

1989 ◽

Vol 23 (10_suppl) ◽

pp. S44-S46

Author(s):

Linda S. Bullock

Keyword(s):

Amino Acids ◽

Amino Acid ◽

Parenteral Nutrition ◽

Gastrointestinal Bleeding ◽

Total Parenteral Nutrition ◽

Critically Ill ◽

Critically Ill Patients ◽

Room Temperature ◽

Acid Solutions ◽

Amino Acid Solutions

The use of histamine2-receptor antagonists could be beneficial in critically ill patients for protection against stress-induced gastrointestinal bleeding. Famotidine, similar to cimetidine and ranitidine, is stable when mixed in dextrose 5% injection and NaCl 0.9% injection at a concentration of 200 μg/mL and stored in polyvinyl chloride bags at 4 °C for 14 days or when frozen for 28 days and subsequently refrigerated for 14 days. Furthermore, famotidine, also like cimetidine and ranitidine, is stable when added to most common total parenteral nutrition (TPN) solutions. Famotidine in concentrations of 20 mg/L and 40 mg/L is stable in crystalline amino acid solutions (20 g/L and 42.5 g/L) when refrigerated for 24 hours, then held at room temperature for 24 hours, at room temperature for 48 hours, or refrigerated for seven days. The concentration of amino acids in the TPN solutions containing 42.5 g/L also is not affected by the addition of famotidine 40 mg/L when stored under conditions similar to those stated above for 48 hours. TPN solutions remain clear and free of turbidity.

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Swelling behavior of montmorillonite cation exchanged for ω-amino acids by ∊-caprolactam

Journal of Materials Research ◽

10.1557/jmr.1993.1174 ◽

1993 ◽

Vol 8 (5) ◽

pp. 1174-1178 ◽

Cited By ~ 671

Author(s):

Arimitsu Usuki ◽

Masaya Kawasumi ◽

Yoshitsugu Kojima ◽

Akane Okada ◽

Toshio Kurauchi ◽

...

Keyword(s):

Amino Acids ◽

Amino Acid ◽

Room Temperature ◽

Carbon Number ◽

Nylon 6 ◽

Basal Spacing ◽

X Ray Diffraction ◽

X Ray ◽

Intercalated Compounds ◽

Silicate Layers

Natural Na-montmorillonite was cation exchanged for the ammonium cations of various ω-amino acids [H3N+(CH2)n−1 COOH, n = 2, 3, 4, 5, 6, 8, 11, 12, and 18]. X-ray diffraction (XRD) results suggested that the chain axes of ω-amino acids with a carbon number of eight or less were parallel to the silicate layers, and that the chain axes of those with a carbon number of 11 or more were slanted to the layers. The cation-exchanged montmorillonites form intercalated compounds with ∊-caprolactam at 25 °C. The montmorillonites intercalated with both ω-amino acid and ∊-caprolactam were studied by XRD measurement at room temperature and 100 °C. We propose a model where amino acid molecules were arranged perpendicular to silicate layers and ∊-caprolactam molecules filled the space between them. When the ∊-caprolactam was melted at 100 °C, the basal spacing for the montmorillonite increased, in which the carbon number exceeds 11. This phenomenon will be applicable to obtaining the nylon 6-clay hybrid, a molecular composite of nylon 6 and montmorillonite.

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