SYNTHESIS OF A NEW α-AMINO ACID, S-METHYL-β,β-DIMETHYLCYSTEINE

1946 ◽  
Vol 24b (1) ◽  
pp. 28-36 ◽  
Author(s):  
Kenneth Savard ◽  
Edwin M. Richardson ◽  
Gordon A. Grant
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Methyl Ester ◽  
Ethyl Ester ◽  
Ester Hydrochloride ◽  
First Time

A new sulphur-containing α-amino acid, S-methyl-β,β-dimethylcysteine has been prepared from S-benzyl-β,β-dimethylcysteine. These two compounds and the intermediate β,β-dimethylcysteine may be of physiological importance.S-Benzyl-β,β-dimethylcysteine has been prepared by the addition of benzyl mercaptan to α-benzoylamino-β,β-dimethylacrylic acid, its azlactone, and methyl ester, followed by hydrolysis.In addition to the above three new sulphur-containing α-amino acids, the following compounds are described, as far as the authors are aware, for the first time: methyl α-benzoylamino-β,β-dimethylacrylate, S-benzyl-N-benzoyl-β,β-dimethylcysteine and its methyl ester, the hydantoin of S-benzyl-β,β-dimethylcysteine, and S-benzyl-β,β-dimethylcysteine ethyl ester hydrochloride, and helianthate.

Single Amino Acid Based Self-Assemblies of Cysteine and Methionine

2018 ◽  
Author(s):  
Nidhi Gour ◽  
Bharti Koshti ◽  
Chandra Kanth P. ◽  
Dhruvi Shah ◽  
Vivek Shinh Kshatriya ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Self Assembly ◽  
Aromatic Amino Acids ◽  
Neutral Condition ◽  
Single Amino Acid ◽  
Binding Assays ◽  
Human Neuroblastoma ◽  
Cytotoxicity Assays ◽  
First Time

We report for the very first time self-assembly of Cysteine and Methionine to discrenible strucutres under neutral condition. To get insights into the structure formation, thioflavin T and Congo red binding assays were done which revealed that aggregates may not have amyloid like characteristics. The nature of interactions which lead to such self-assemblies was purported by coincubating assemblies in urea and mercaptoethanol. Further interaction of aggregates with short amyloidogenic dipeptide diphenylalanine (FF) was assessed. While cysteine aggregates completely disrupted FF fibres, methionine albeit triggered fibrillation. The cytotoxicity assays of cysteine and methionine structures were performed on Human Neuroblastoma IMR-32 cells which suggested that aggregates are not cytotoxic in nature and thus, may not have amyloid like etiology. The results presented in the manuscript are striking, since to the best of our knowledge,this is the first report which demonstrates that even non-aromatic amino acids (cysteine and methionine) can undergo spontaneous self-assembly to form ordered aggregates.

Access to 2-Arylquinazolines via Catabolism/Reconstruction of Amino Acids with Insertion of Dimethyl Sulfoxide

2021 ◽  
Author(s):  
Jin-Tian Ma ◽  
Li-Sheng Wang ◽  
Zhi Chai ◽  
Xin-Feng Chen ◽  
Bo-Cheng Tang ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Dimethyl Sulfoxide ◽  
Nitrogen Source ◽  
Carbon And Nitrogen ◽  
First Time

Quinazoline skeletons are synthesized by amino acids catabolism/reconstruction combined with dimethyl sulfoxide insertion/cyclization for the first time. The amino acid acts as a carbon and nitrogen source through HI-mediated catabolism...

The 4-(methylthio)phenyl ester for the synthesis of polypeptides of a known repeating sequence of amino acids. Synthesis of poly-(L-lysylglycyl)glycine 1-C14 ethyl ester hydrobromide

1970 ◽  
Vol 48 (16) ◽  
pp. 2509-2511 ◽  
Author(s):  
Brian J. Johnson ◽  
Donna S. Rea
Keyword(s):  
Amino Acids ◽  
Ethyl Ester ◽  
Title Compound ◽  
Ester Hydrochloride ◽  
Phenyl Ester ◽  
Protecting Group ◽  
High Dilution ◽  
Protective Groups ◽  
Protected Tetrapeptide

The synthesis of the tetrapeptide, N-t-butoxycarbonyl-ε-N-carbobenzoxy-L-lysylglycyl-ε-N-carbobenzoxy-L-lysylglycine 4-(methylthio)phenyl ester is described. The utility of this protective ester is shown by its easy conversion to the protected tetrapeptide 4-(methylsulfonyl)phenyl activated ester without decomposition. Removal of the N-butoxycarbonyl protecting group afforded the polymerizing unit, ε-N-carbobenzoxy-L-lysylglycyl-ε-N-carbobenzoxy-L-lysylglycine 4-(methylsulfonyl)phenyl ester. Polymerization of this material on the partially blocked monomer glycine-1-C14 ethyl ester hydrochloride, at a relatively high dilution, gave poly-(ε-N-carbobenzoxyl-L-lysylglycyl)glycine-1-C14 ethyl ester. The carbobenzoxy protective groups were removed to give the title compound.

On the Possible Spatial Structures of the β – Amyloid.

2022 ◽  
Vol 7 (1) ◽  
pp. 0-0
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Spatial Structure ◽  
Spatial Models ◽  
Globular Proteins ◽  
Spatial Structures ◽  
Higher Dimensional ◽  
Protein Molecules ◽  
Β Amyloid ◽  
First Time

Spatial models of the β - structures of protein molecules, forming layers of amino acids, in principle, of unlimited length for both antiparallel and parallel conformation have been constructed. It is shown that the simplified flat Pauling models do not reflect the spatial structure of these layers. Using the recently developed theory of higher-dimensional polytopic prismahedrons, models of the volumetric filling of space with amino acid molecules are constructed. The constructed models for the first time mathematically describe the native structures of globular proteins.

scholarly journals Bakerian lecture - Amino-acid analysis and the structure of proteins

1942 ◽  
Vol 131 (863) ◽  
pp. 136-160 ◽  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Analysis ◽  
Nutritive Value ◽  
Analytical Data ◽  
Seed Proteins ◽  
Decomposition Products ◽  
First Time ◽  
Structure Of Proteins

In recent years the X-ray crystallographers have made remarkable advances in the interpretation of protein structure, and it is becoming more and more evident that a stage has been reached when their views need to be reconciled with data obtained from accurate amino-acid analysis of the proteins concerned. In all too many cases these data are, unfortunately, not yet available, and the reason why the analyst cannot supply them at short notice is due not so much to the com­plexity of the problem—which he has never sought to minimize—but to the fact that many of the more important methods of analysis in current use are an inheritance from an earlier period when such accuracy as is now demanded would have been considered almost impossible of achievement. From about 1840 until 1900, following the lead given by Liebig and later by Ritthausen, the attention of protein chemists was centred chiefly on the prepara­tion and characterization of various animal and seed proteins; as substances of physiological interest their enzymic digestion products were studied in elaborate detail by Kühne, but little attention was paid to the ultimate decomposition products, the amino-acids, in spite of the fact that Ritthausen as early as 1872 had pointed out that the proportions in which these occur might be characteristic of the protein concerned. The enunciation by Hofmeister and Fischer of the peptide hypothesis in 1901 emphasized for the first time the fundamental importance of the amino-acids, and a most fruitful period followed in which attention became almost exclusively focused on these products. Under the inspiring leadership of Fischer himself great improvements were effected in the separation and identification of the amino-acids, so that by about 1915 reasonably good analyses were available for most of the better-known proteins. Though far from complete, the analytical data showed quite clearly that proteins could differ widely in composition, and in many cases it was possible to correlate composition with nutritive value. Such an aim was, indeed, the incentive behind much of the work of this period.

scholarly journals Brooding fathers, not siblings, take up nutrients from embryos

2009 ◽  
Vol 277 (1683) ◽  
pp. 971-977 ◽  
Author(s):  
Gry Sagebakken ◽  
Ingrid Ahnesjö ◽  
Kenyon B. Mobley ◽  
Inês Braga Gonçalves ◽  
Charlotta Kvarnemo
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Nutrient Uptake ◽  
Muscle Tissue ◽  
Brood Pouch ◽  
The Other ◽  
Syngnathus Typhle ◽  
Brooding Period ◽  
Male Brood ◽  
First Time

It is well known that many animals with placenta-like structures provide their embryos with nutrients and oxygen. However, we demonstrate here that nutrients can pass the other way, from embryos to the parent. The study was done on a pipefish, Syngnathus typhle , in which males brood fertilized eggs in a brood pouch for several weeks. Earlier research has found a reduction of embryo numbers during the brooding period, but the fate of the nutrients from these ‘reduced’ embryos has been unknown. In this study, we considered whether (i) the brooding male absorbs the nutrients, (ii) siblings absorb them, or (iii) a combination of both. Males were mated to two sets of females, one of which had radioactively labelled eggs (using 14 C-labelled amino acids), such that approximately half the eggs in the brood pouch were labelled. This allowed us to trace nutrient uptake from these embryos. We detected that 14 C-labelled amino acids were transferred to the male brood pouch, liver and muscle tissue. However, we did not detect any significant 14 C-labelled amino-acid absorption by the non-labelled half-siblings in the brood pouch. Thus, we show, to our knowledge, for the first time, that males absorb nutrients derived from embryos through their paternal brood pouch.

scholarly journals Synthesis and Atiplatelet of 2-(ethyl amino acid esters), Amino pyridyl 1,3- oxzine

2006 ◽  
Vol 2 (2) ◽  
pp. 91-97
Author(s):  
Mohamad Alajelee
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Methyl Ester ◽  
Elemental Analysis ◽  
Inhibitory Activity ◽  
Amino Acid Esters ◽  
Improved Method ◽  
Acid Esters

2-(N-glycyl ,Alanyl , leucinyl , isoleacinyl , methionyl , phenyl alanyl,  vilinyl methyl ester) , 2-Amino and 4- Amino pyrideyl -1,3- Benzoxazine -4- one were synthesized from the reaction of the corresponding amino acids ester , Amino pyridines with methyl cyano salicylate using improved method. The resulted benzoxazine derivative were tested for their Antiplatelet inhibitory activity , their IR , NMR (1H , 13C) were also studied and checked by elemental analysis.

AMINOACIDURIA IN RATS AFTER TREATMENT WITH THE ETHYL ESTER OF GAMMA-BUTYROBETAINE

1960 ◽  
Vol 38 (1) ◽  
pp. 837-843 ◽  
Author(s):  
Esau A. Hosein ◽  
Margaret Smart ◽  
Kathleen Hawkins
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Muscular Dystrophy ◽  
Ethyl Ester ◽  
Chromatographic Analysis ◽  
Intramuscular Injection ◽  
Muscle Proteins

Previous workers have shown that the urine of patients with muscular dystrophy contains excessive amounts of amino acids. Using paper chromatographic analysis, these workers found that the amino acid methylhistidine is among those excreted in large amounts. Rats do not normally excrete methylhistidine, but in our experiments it was found that intramuscular injection of the ethyl ester of gamma-butyrobetaine into rats caused both the excretion of methylhistidine and an excessive aminoaciduria, presumably through the breakdown of muscle proteins.

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.

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