SYNTHESIS OF α-AMINO ACIDS FROM ETHYL CYANOACETATE

1952 ◽  
Vol 30 (8) ◽  
pp. 592-597 ◽  
Author(s):  
Paul E. Gagnon ◽  
Guy Nadeau ◽  
Raymond Côté

Monosubstituted cyanoacetic esters, obtained by condensation of 1-bromo-3(s)-phenoxypropanes (s = o-Cl, o-Br, o-I, o-, m-, and p-NO2) or 1-bromo-2(s)-phenoxyethanes (s = o-Cl, o-Br, o-I, and m-NO2) with ethyl cyanoacetate by means of potassium carbonate, were transformed through a Curtius degradation into cyanoacetisocyanates. These compounds by hydrolysis in acid or alkaline medium gave α-amino acids. However, hydrolysis of the corresponding carbobenzyloxy- or carbethoxyaminonitriles afforded better yields. The carbobenzyloxyaminonitriles were more readily hydrolyzed in aqueous hydrochloric acid than the carbethoxyaminonitriles. Moreover, the mild action of dry hydrochloric acid on the carbobenzyloxy derivatives yielded the α-amino acids readily whereas similar treatment of the carbethoxy derivatives gave the carbethoxyamino acids.

1971 ◽  
Vol 24 (4) ◽  
pp. 1247 ◽  
Author(s):  
AS Inglis ◽  
PW Nicholls ◽  
CM Roxburgh

The phenylthiohydantoins (PTHs) derived from amino acids were hydrolysed in boiling hydriodic acid for 24 hr. Good yields of free amino acids were obtained for all PTH derivatives except methionine. In contrast to hydrolysis with hydrochloric acid, hydrolysis with hydriodic acid converts PTH-threonine, PTH-serine, and PTH-tryptophan respectively to oc-amino-n-butyric acid, alanine, and a mixture (approx. 2: 1) of glycine and alanine. This procedure provides a useful adjunct to thin-layer chromatography and ultraviolet spectroscopy for quantitative identification of the PTH derivative.


1948 ◽  
Vol 26b (7) ◽  
pp. 503-510 ◽  
Author(s):  
Paul E. Gagnon ◽  
Jean L. Boivin

Nine α-amino acids, namely, dl-alanine, dl-α-aminobutyric acid, dl-α-ammoenanthic acid, dl-α-amino-γ-phenoxybutyric acid, dl-C-phenylglycine, dl-proline, dl-ornithine, dl-lysine and 2-aminoindane-2-carboxylic acid have been prepared from α-substituted cyanoacetic esters. Pyrrolidine or piperidine was isolated when it was attempted to prepare ornithine or lysine by hydrolysis of diurethanes with hydrochloric acid. When a mixture of formic and hydrochloric acids and water was used as hydrolyzing agent, ornithine or lysine was obtained in low yield in addition to traces of pyrrolidine or piperidine. The following compounds, as far as the authors are aware, have been prepared for the first time: α-cyanopropionhydrazide, benzal α-cyanopropionhydrazide, α-cyanopropionic azide, α-carbethoxyaminopropiononitrile, α-cyanobutyrhydrazide, benzal α-cyanobutyrhydrazide, α-cyanobutyric azide, α-carbethoxyaminobutyronitrile, ethyl α-cyanoenanthate, α-cyanoenanthic hydrazide, benzal α-cyanoenanthic hydrazide, α-cyanoenanthic azide, α-carbethoxyaminoenanthonitrile, 5-(n-amyl)-hydantoin, ethyl α-cyano-γ-phenoxybutyrate, ethyl bis-β-phenoxyethylmalonate mononitrile, α-cyano-γ-phenoxybutyrhydrazide, benzal α-cyano-γ-phenoxybutyrhydrazide, α-cyano-γ-phenoxybutyric azide, α-carbethoxyamino-γ-phenoxybutyronitrile, 5-(β-phenoxyethyl)-hydantoin, α-cyano-α-phenylacethydrazide, benzal α-cyano-α-phenylacethydrazide, α-cyano-α-phenylacetic azide, ethyl δ-bromo-α-cyanovalerate, δ-bromo-α-cyanovalerhydrazide, benzal δ-bromo-α-cyanovalerhydrazide, δ-bromo-α-cyanovaleric azide, δ-bromo-α-carbethoxyaminovaleronitrile, dibenzal α-cyanoadipic dihydrazide, α-cyanoadipic diazide, α,δ-dicarbethoxyaminoadiponitrile, dibenzal α-cyanopimelic dihydrazide, α-cyanopimelic diazide, α, ε-dicarbethoxyaminocapronitrile, 2-cyano-2-carbethoxyindane, 2-cyano-2-carboxylindane hydrazide, benzal 2-cyano-2-carboxylindane hydrazide, 2-cyano-2-carboxylindane azide, 2-cyano-2-carbethoxyaminoindane, 2-aminoindane-2-carboxylic acid, 2-aminoindane-2-carboxylic acid hydrochloride.


1973 ◽  
Vol 51 (22) ◽  
pp. 3820-3825 ◽  
Author(s):  
Bruce L. Jensen ◽  
Raymond E. Counsell

The chemistry of DDT and DDD derivatives was explored by studying the steric and electronic effects on the hydrolysis of a variety of substituted diphenylacetaldehyde ethylene glycol cyclic acetals. This investigation demonstrated that ortho substituents, p-nitro, and p-methoxy groups affect the product distribution in different ways. The mechanistic details of this work are discussed.


1975 ◽  
Vol 53 (11) ◽  
pp. 1137-1144 ◽  
Author(s):  
M. Ali ◽  
J. B. Capindale

The release of ammonia by hydrolysis of N-benzoyl-L-asparagine, glycyl-DL-asparagine, L-asparagine, and succinamic acid, and of aniline from N-benzoyl-L-glutamic-α-anilide, N-benzoyl-L-aspartic-α-anilide, L-aspartic-α-anilide, and the monoanilides of succinic and glutaric acids is first-order with respect to substrate in dilute (0.4–0.03 M) aqueous hydrochloric acid at 100 °C. The first-order rate constants (kobs) for these reactions can be expressed as kobs = kintra + k2[H+]. The above hydrolyses are used as models for developing a tentative mechanism to account for the selective release of aspartic acid from proteins under these conditions. The data are also used to suggest reasons why glutamic acid is not released with equal facility.


2012 ◽  
Vol 52 (5) ◽  
pp. 313 ◽  
Author(s):  
Carlos Alvarez ◽  
Manuel Rendueles ◽  
Mario Diaz

Animal blood is the most important waste product from the meat industry due to the huge volumes produced and its pollutant power. Different methods are currently employed to process this by-product, such as drying, incineration or enzymatic hydrolysis. All these techniques are expensive, do not result in revalorisation or are not applicable at an industrial scale. In this paper, chemical hydrolysis is presented as an alternative to recover and increase the value of purified haemoglobin, the most abundant protein in blood. Non-enzymatic hydrolysis of haemoglobin is a good method for obtaining peptides due to its low cost, ease of control and the large amount of peptides produced, as well as being suitable for industrial applications. This paper presents a study of the use of two acids (sulfuric and hydrochloric) for this purpose under different experimental conditions. From the analysis of the kinetics of the hydrolysis process, four fractions can be defined: unbroken haemoglobin, soluble peptides, non-soluble peptides and free amino acids. A kinetic model was developed to simulate the hydrolysis mechanisms, providing a good fit to the experimental results. Both sulfuric and hydrochloric acid at concentrations of 6 M can hydrolyse the haemoglobin completely, but the average peptide size is lower for sulfuric than for hydrochloric acid.


MRS Advances ◽  
2020 ◽  
Vol 5 (52-53) ◽  
pp. 2669-2678
Author(s):  
Jeovani González P. ◽  
Ramiro Escudero G

AbstractDeinking of recycled office (MOW) paper was carried out by using a flotation column and adding separately sodium hydroxide, and the enzyme Cellulase Thricodema Sp., as defibrillators.The de-inked cellulose fibers were characterized according to the standards of the paper industry, to compare the efficiency of the deinking of each chemical reagent used to hydrolyze the fibers and defibrillate them.The computational simulation of the molecular coupling between the enzyme and cellulose was performed, to establish the enzyme-cellulose molecular complex and then to identify the principal amino-acids of endo-β-1,4-D-glucanase in this molecular link, which are responsible for the hydrolysis of the cellulose.Experimental results show the feasibility to replace sodium hydroxide with the enzyme Cellulase Thricodema Sp., by obtaining deinked cellulose with similar optical and physical properties.The use of the enzyme instead of sodium hydroxide avoids the contamination of the residual water; in addition to that, the column is operated more easily, taking into consideration that the pH of the system goes from alkaline to neutral.


2018 ◽  
Vol 69 (10) ◽  
pp. 2794-2798
Author(s):  
Alina Diana Panainte ◽  
Ionela Daniela Morariu ◽  
Nela Bibire ◽  
Madalina Vieriu ◽  
Gladiola Tantaru ◽  
...  

A peptidic hydrolysate has been obtained through hydrolysis of bovine hemoglobin using pepsin. The fractioning of the hydrolysate was performed on a column packed with CM-Sepharose Fast Flow. The hydrolysate and each fraction was filtered and then injected into a HPLC system equipped with a Vydak C4 reverse phase column (0.46 x 25 cm), suitable for the chromatographic separation of large peptides with 20 to 30 amino acids. The detection was done using mass spectrometry, and the retention time, size and distribution of the peptides were determined.


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