GAS CHROMATOGRAPHIC METHOD FOR THE SEPARATION AND ESTIMATION OF AMINO ACID DERIVATIVES

1965 ◽  
Vol 43 (3) ◽  
pp. 309-315 ◽  
Author(s):  
P. B. Hagen ◽  
W. Black
Keyword(s):  
Amino Acids ◽  
Gas Chromatography ◽  
Amino Acid ◽  
Methyl Ester ◽  
Chromatographic Method ◽  
Methyl Esters ◽  
Amino Acid Derivatives ◽  
Constant Proportion ◽  
Gas Chromatographic Method

It has been possible to prepare the N-trifluoroacetyl methyl esters of the 19 amino acids commonly found in proteins and to separate them by gas chromatography on two types of column, Carbowax 1540 and Carbowax 20M. There is a constant relation between the amount of each amino acid and the size of the recorded peak. This indicates either that the conversion to the derivative is quantitative or that a constant proportion of each amino acid is converted to its N-trifluoroacetyl methyl ester.

scholarly journals Digestibility of amino acids in pig diets containing Eurolysine bacterial protein or Pekilo protein, with special reference to a gas chromatographic method used in amino acid determination

1982 ◽  
Vol 54 (4) ◽  
pp. 279-285
Author(s):  
Matti Näsi ◽  
Lea Huida
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Soybean Meal ◽  
Chromatographic Method ◽  
Latin Squares ◽  
Growing Pigs ◽  
Bacterial Protein ◽  
Amino Acid Determination ◽  
Gas Chromatographic Method ◽  
Acid Determination

The apparent faecal digestibilities of amino acids were determined in growing pigs on diets in which 50% or 100 % soybean meal supplement was replaced by Eurolysine bacterial protein or Pekilo protein. The trial was conducted as two 3X3 Latin squares with six castrated pigs. Compared with the soybean meal supplement, the Eurolysine diet had lower (P < 0.05) digestibilities of arginine, leucine, methionine, phenylalanine and tyrosine. Compared with the Pekilo diet the Eurolysine diet had lower digestibilities (P < 0.05) of alanine, aspartic acid, glutamic acid, glycine, leucine, proline and serine. Lysine digestibility was higher on the Eurolysine diet than on the Pekilo diet. A gas chromatographic method used in amino acid determination is described and evaluated.

scholarly journals Responses of cultured cardiac myocytes to lysosomotropic compounds and methylated amino acids

1985 ◽  
Vol 74 (1) ◽  
pp. 119-135
Author(s):  
R.S. Decker ◽  
M.L. Decker ◽  
V. Thomas ◽  
J.W. Fuseler
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Methyl Ester ◽  
Acridine Orange ◽  
Cardiac Myocytes ◽  
Methyl Esters ◽  
Acid Proteinase ◽  
Weak Bases ◽  
Acid Methyl ◽  
Amino Acid Methyl Esters

Cardiac myocytes whose lysosomes had been pre-labelled with acridine orange were exposed to either L-amino acid methyl esters (L-leucine or methionine methyl ester) or to ‘lysosomotropic’ weak bases (chloroquine, methylamine, and NH4Cl) for 1 h. Both types of interventions dilated lysosomes equally and inhibited proteolysis to varying degrees. The weak bases produced no apparent alterations in the acridine orange staining, whereas the methylated amino acids induced a marked redistribution of the fluorescent dye from lysosomes into the myoplasm, suggesting that they may have provoked a change in lysosomal membrane permeability. A brief exposure to weak bases failed to enhance acid proteinase secretion into the culture medium but apparently inactivated cellular cathepsin B activity. In contrast, methylated amino acids induced no alterations in acid proteinase activity or the cellular distribution of the two proteolytic enzymes. Lastly, weak bases markedly elevated intralysosomal pH as measured with fluorescein dextran, while only modest rises were observed after amino acid methyl ester treatment. The present observations imply that amino acid methyl esters represent a new class of reagents with actions distinctly different from those of chloroquine and NH4Cl, and they may provide a unique and valuable means of studying secondary lysosomal function in cell culture.

Analysis of Amino Acids by Gas Chromatography as the N-Trifluoroacetyl η-Butyl Esters

1987 ◽  
Vol 70 (1) ◽  
pp. 160-170
Author(s):  
Charles W Gehrke ◽  
Kenneth C Kuo ◽  
Floyd E Kaiser ◽  
Robert W Zumwalt
Keyword(s):  
Amino Acids ◽  
Gas Chromatography ◽  
Amino Acid ◽  
Ion Exchange ◽  
Butyl Ester ◽  
Exchange Chromatography ◽  
Experimental Conditions ◽  
Butyl Esters ◽  
Collaborative Studies ◽  
Gas Chromatographic Method

Abstract This presentation describes amino acid analysis with the gas chromatographic method and experimental conditions using the N-trifluoroacetyl n-butyl ester derivatives; the study we describe here was undertaken to compare gas chromatographic (GC) and ion-exchange chromatographic (IEC) analyses of amino acids in hydrolysates of 9 diverse sample types to gain insight into effects of these 2 chromatographic methods of analysis on variation in amino acid results. Our study showed that values for samples prepared by 2 separate laboratories using the same procedure were generally in good agreement when all of the hydrolysates were analyzed by a single laboratory using a single method of analysis. To compare results from gas chromatography with those from ion-exchange chromatography analyses were performed by 2 different laboratories on the same hydrolysates and on different hydrolysates prepared by the same method by both laboratories. The data demonstrate that GC and IEC can be expected to yield essentially identical results when applied to the same hydrolysate. Agreement is so close that interlaboratory differences in hydrolysate preparation of the same sample contribute as much to variation in amino acid results as does the method of analysis, a fact which should be noted in planning collaborative studies.

The Importance of Alcohol Testing by Gas Chromatography vs the Cordebard Classical Method Modified in the Medico Legal Investigation

2018 ◽  
Vol 69 (9) ◽  
pp. 2407-2410
Author(s):  
Dan Perju Dumbrava ◽  
Carmen Corina Radu ◽  
Sofia David ◽  
Tatiana Iov ◽  
Catalin Jan Iov ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Chromatographic Method ◽  
Classical Method ◽  
Blood Alcohol Concentration ◽  
Alcohol Concentration ◽  
Blood Alcohol ◽  
Technical Details ◽  
Gas Chromatographic Method ◽  
Alcohol Testing ◽  
Living Person

Considering the growing number of requests from the criminal investigations authorities addressed to the institutions of legal medicine, testing of blood alcohol concentration both in the living person and in the corpse, we believe that a presentation of the two methods which are used in our country, is a topic of interest at present. The purpose of this article is to provide the reader with the technical details on how blodd alcohol concentration is realised by means of the gas chromatographic method and the classical one, (Cordebard modified by D. Banciu and I. Droc) respectively. Another purpose of this article is to also show, in a comparative way, the elements that make the gas chromatographic method superior to the former one.

scholarly journals Novel Amino Acid Derivatives of Quinolines as Potential Antibacterial and Fluorophore Agents

2020 ◽  
Vol 88 (4) ◽  
pp. 57
Author(s):  
Oussama Moussaoui ◽  
Rajendra Bhadane ◽  
Riham Sghyar ◽  
El Mestafa El Hadrami ◽  
Soukaina El Amrani ◽  
...  
Keyword(s):  
Amino Acid ◽  
Methyl Esters ◽  
Amino Acid Derivatives ◽  
Bacterial Strains ◽  
Fluorescent Properties ◽  
Topoisomerase Iv ◽  
Microdilution Method ◽  
Hydrolysis Of ◽  
Derivatives Of

A new series of amino acid derivatives of quinolines was synthesized through the hydrolysis of amino acid methyl esters of quinoline carboxamides with alkali hydroxide. The compounds were purified on silica gel by column chromatography and further characterized by TLC, NMR and ESI-TOF mass spectrometry. All compounds were screened for in vitro antimicrobial activity against different bacterial strains using the microdilution method. Most of the synthesized amino acid-quinolines show more potent or equipotent inhibitory action against the tested bacteria than their correspond esters. In addition, many of them exhibit fluorescent properties and could possibly be utilized as fluorophores. Molecular docking and simulation studies of the compounds at putative bacterial target enzymes suggest that the antimicrobial potency of these synthesized analogues could be due to enzyme inhibition via their favorable binding at the fluoroquinolone binding site at the GyrA subunit of DNA gyrase and/or the ParC subunit of topoisomerase-IV.

Gas Chromatographic Determination of N-Butyl-N-ethyl-α,α,α-trifluoro-2,6-dinitro-p-toluidine and α,α,α-Trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine in Formulations

1971 ◽  
Vol 54 (3) ◽  
pp. 711-712
Author(s):  
Martha Fuzesi
Keyword(s):  
Gas Chromatography ◽  
Quantitative Determination ◽  
Electron Capture ◽  
Chromatographic Method ◽  
Chromatographic Determination ◽  
Electron Capture Detector ◽  
Reference Solution ◽  
Gas Chromatographic Method

Abstract A gas chromatographic method is described for the quantitative determination of N-butyl-N-ethyl-α,α,α-trifluoro-2,6-dinitro-p-tolindine and α,α,α-trifluoro-2,6-dinitro-N,N-dipropyI-p-toluidine herbicides in formulations. The sample is extracted with benzene, and equal amounts of sample and reference solution in the same concentration range are analyzed by gas chromatography, using an electron capture detector and an SE-30/Diatoport S column. The method has been applied successfully to laboratory-prepared and commercial samples.

Antioxidants (BHA and BHT) in Breakfast Cereals

1965 ◽  
Vol 48 (4) ◽  
pp. 694-699
Author(s):  
David M Takahashi
Keyword(s):  
Gas Chromatography ◽  
Petroleum Ether ◽  
Chromatographic Method ◽  
Steam Distillation ◽  
Gas Chromatograph ◽  
Breakfast Cereals ◽  
Collaborative Studies ◽  
Different Types ◽  
Gas Chromatographic Method

Abstract Antioxidants (BHA and BHT) in different types of breakfast cereals were studied by argon ionization gas chromatography. Samples containing antioxidants were packed into the column, and antioxidants were eluted with redistilled petroleum ether. EIuates were concentrated under N2 and injected into a Barber-Colman Model 10 gas chromatograph. Recoveries ranged from about 92 to 110%. Results obtained by steam distillation-colorimetry methods were erratic. Colorimetric procedures were not free from interferences and could lead to highly erroneous results at the lower ppm levels. The gas chromatographic method is faster, simpler, and more accurate. Collaborative studies on corn and rice ready-to-eat breakfast cereals are recommended.

Sodium borohydride: A versatile reagent in the reductive N-monoalkylation of α-amino acids and α-amino methyl esters

2002 ◽  
Vol 80 (7) ◽  
pp. 779-788 ◽  
Author(s):  
Giancarlo Verardo ◽  
Paola Geatti ◽  
Elena Pol ◽  
Angelo G Giumanini
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Sodium Borohydride ◽  
Carbonyl Compounds ◽  
Condensation Reaction ◽  
Methyl Esters ◽  
Reducing Agent ◽  
Reductive Condensation ◽  
Versatile Reagent

α-Amino acids and α-amino methyl esters are easily converted to their N-monoalkyl derivatives by a reductive condensation reaction using several carbonyl compounds in the presence of sodium borohydride. This reducing agent has shown a wide versatility with minor but essential procedural variations. The reaction allows the α-monodeuterium labeling of the new N-substituent by use of sodium borodeuteride.Key words: α-amino acid, α-amino methyl esters, sodium borohydride, reductive N-monoalkylation, carbonyl compounds.

A new gas chromatographic method for determination of amino acid levels in human serum

1980 ◽  
Vol 105 (2) ◽  
pp. 201-211 ◽  
Author(s):  
Hartmut Frank ◽  
Albert Rettenmeier ◽  
Helmut Weicker ◽  
Graeme J. Nicholson ◽  
Ernst Bayer
Keyword(s):  
Amino Acid ◽  
Human Serum ◽  
Chromatographic Method ◽  
Amino Acid Levels ◽  
Gas Chromatographic Method
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