Sequential degradation of peptides from their carboxyl termini with ammonium thiocyanate and acetic anhydride

Biochemistry ◽  
1968 ◽  
Vol 7 (5) ◽  
pp. 1796-1807 ◽  
Author(s):  
George R. Stark
Keyword(s):  
Acetic Anhydride ◽  
Ammonium Thiocyanate ◽  
Degradation Of Peptides

Thiohydantoins. I. The Preparation of Some 2-Thiohydantoins from Amino Acids and Acylamino Acids

1952 ◽  
Vol 5 (4) ◽  
pp. 711 ◽  
Author(s):  
JM Swan
Keyword(s):  
Amino Acids ◽  
Acetic Anhydride ◽  
Ammonium Thiocyanate ◽  
Acyl Derivatives ◽  
Degradation Of Peptides

A reinvestigation of the stepwise degradation of peptides and proteins by the Schlack and Kumpf (1926) procedure, which involves conversion of the terminal carboxyl residue to a 5-substituted-2-thiohydantoin; has been undertaken. The following amino acids or their aoetyl derivatives have been converted by warming with acetic anhydride and ammonium thiocyanate into the corresponding 1-acetyl-2-thio-hydantoins: valine, methionine, isoleucine, α-aminophenylacetic acid, tryptophane, histidine, and tyrosine. These new 1-acetyl-2-thiohydantoins, as well as others, have been deacetylated by an improved procedure. Certain 1-acyl-5-carbethoxy-2-thio- hydantoins on hydrolysis give 2-thiohydantoin only. N-acetylthreonine, acetic anhydride, and ammonium thiocyanate produce 5-ethylidene-2-thiohydantoin, also obtained by the condensation of acetaldehyde with 2-thiohydantoin or its 1-acyl derivatives, or from the interaction of ammonium thiocyanate with 2-phenyl-4-ethylideneoxazol-5-one. This type of rearrangement occurs in other cases.

Thiohydantoins. II. Thiohydantoins Derived from Aspartic and Glutamic Acids

1952 ◽  
Vol 5 (4) ◽  
pp. 721
Author(s):  
JM Swan
Keyword(s):  
Acetic Anhydride ◽  
Carboxylic Acids ◽  
Ammonium Thiocyanate ◽  
Derivatives Of ◽  
Isomeric Pairs ◽  
Acyl Derivatives

N-Acyl derivatives of the &carboxylic acids, aspartic and glutamic acids, yield the corresponding anhydrides when heated with acetic anhydride in the presence or absence of ammonium thiocyanate. In general these anhydrides form isomeric pairs of amides and anilides, and only one of each pair can be converted into the corresponding 2-thiohydantoin. The anhydrides from N-phenylacetyl- and N-p-nitro-benzoylglutamic acids, and N-acetylaspartic acid have been regarded hitherto as oxazolones.

Thiohydantoins. III. Anhydride Intermediates in the Formation of 1-Acyl-2-thiohydantoins from Acylamino Acids

1952 ◽  
Vol 5 (4) ◽  
pp. 728
Author(s):  
JM Swan
Keyword(s):  
Carbon Dioxide ◽  
Acetic Acid ◽  
Acetic Anhydride ◽  
Hippuric Acid ◽  
Ammonium Thiocyanate ◽  
High Yield ◽  
Mixed Anhydride

Linear anhydrides are formed by the action of acetic anhydride on p-toluene-sulphonylglycine and carbobenzyloxy-glycine, -phenylalanine, and -β-alanine. The anhydrides from the first two acids yield the corresponding 2-thiohydantoin with ammonium thiocyanate in acetic acid. Other methods for the preparation of l-p-toluenesulphonylglycine anhydride, and its 2-thiohydantoin, are also given. Hippuric acid, with ethyl chlorocarbonate and triethylamine yields ethyl hippurate, probably via the mixed anhydride and 2-phenyloxazol-5-one. The inclusion of ammonium thiocyanate gives 1-benzoyl-2-thiohydantoin in high yield. The N-carboxy anhydride of phenylalanine (4-benzyloxazolid-2,5-dione) also reacts with ammonium thiocyanate to give carbon dioxide and 5-benzyl-2-thiohydantoin.

Studies in Thiohydantoin Chemistry. I. Some Aspects of the Schlack-Kumpf Reaction

1996 ◽  
Vol 49 (5) ◽  
pp. 541 ◽  
Author(s):  
BM Duggan ◽  
RL Laslett ◽  
JFK Wilshire
Keyword(s):  
Amino Acids ◽  
Acetic Acid ◽  
Acetic Anhydride ◽  
Ammonium Thiocyanate ◽  
Sodium Thiocyanate ◽  
Side Chains ◽  
Derivatives Of

An investigation has been carried out into the Schlack-Kumpf reaction, i.e., the reaction of amino acids with a mixture of acetic anhydride, acetic acid and sodium thiocyanate (occasionally ammonium thiocyanate was used). Particular emphasis was placed on the reactions with amino acids containing sensitive or functional side chains, i.e., serine, threonine , arginine , proline , lysine, histidine , cysteine , and aspartic and glutamic acids. The reaction of serine, and of certain of its O- and N-substituted derivatives, takes an unusual course to give an acetylated thiohydantoin derivative of cysteine. Correspondingly, threonine gives an acetylated thiohydantoin derivative of β- methylcysteine. Similar reactions occurred with the 3-phenylthiohydantoin derivatives of serine and of threonine to give acetylated thiohydantoin derivatives of cysteine and of β-methylcysteine respectively.

Separation of Plasminogen Activators from Human Uterine Tissue and a Comparison with Activators from Human Urine and Porcine Tissue

1979 ◽  
Vol 41 (04) ◽  
pp. 718-733 ◽  
Author(s):  
Preben Kok
Keyword(s):  
Plasminogen Activator ◽  
Human Urine ◽  
Gel Filtration ◽  
Ammonium Thiocyanate ◽  
Plasminogen Activators ◽  
Particle Sizes ◽  
Uterine Tissue ◽  
Porcine Tissue ◽  
Major Activity ◽  
Proliferative Phase

SummaryThree types of plasminogen activator could be distinguished in extracts from human uterine tissue. The activators differed in thermostability or in mode of inhibition by EACA.All the extracts contained stable as well as labile activators. The saline extracts were uniformly inhibited by increasing concentrations of EACA. Extracts made with 2 M ammonium thiocyanate were either uniformly inhibited by EACA or showed deflections indicating contamination with an activator, which was inhibited in a biphasic manner. It was possible to distinguish between: (1) An activator, abundantly present in the tissue, which was uniformly inhibited and stable. (2) Another uniformly inhibited activator, which was labile. (3) An activator, inhibited in a biphasic manner, similar to urokinase, which was present in varying amounts in uteri with the endometrium in the proliferative phase.Gel filtration of the uterine extracts showed two major activity peaks corresponding to particle sizes of 60,000 dalton and about 10,000 dalton.Antiserum to purified plasminogen activator, prepared from porcine ovaries, inhibited the activity of the human uterine extracts, but not the activities of human urokinase or urine. Urokinase antiserum in a concentration completely inhibiting human urine or urokinase, inhibited only 10% or less of the activities of human uterine extracts.

DETERMINATION OF ALDOSTERONE AND DEOXYCORTICOSTERONE IN PLASMA USING 3H-ACETIC ANHYDRIDE AND VAPOUR PHASE ACETYLATION

1969 ◽  
Vol 61 (1_Suppl) ◽  
pp. S12 ◽  
Author(s):  
V. H. T. James ◽  
A. E. Rippon ◽  
M. L. Arnold
Keyword(s):  
Acetic Anhydride ◽  
Vapour Phase

Syntheses and Cytotoxicity Screening of some Novel 1,2,4-Triazine Derivatives against Liver Carcinoma Cell Lines

2020 ◽  
Vol 17 ◽  
Author(s):  
W. Abd El-Fattah
Keyword(s):  
Acetic Anhydride ◽  
Cell Lines ◽  
Carcinoma Cell ◽  
Aromatic Aldehydes ◽  
Liver Carcinoma ◽  
Anticancer Activities ◽  
Carcinoma Cell Lines ◽  
Elemental Analyses ◽  
Triazine Derivatives ◽  
C Nmr

: In this work, 1,2,4-triazine derivatives were synthesized and evaluated for anticancer activities. Series of 1,2,4-triazine derivatives (4a, b) were prepared via the reaction of N-benzoyl glycine (1) with aromatic aldehydes in presence of fused sodium acetate and acetic anhydride to give 1,3-oxazolinone derivatives (2a, b), followed by condensation with 1-(ethoxycarbonyl) hydrazine (3) in glacial acetic acid. Compounds (4a, b) then reacted with acetic anhydride, ethyl chloroacetate and 2,4-dinitrophenyl hydrazine yielded the corresponding to N-acetyl derivatives (5a, b), N-(ethoxycarbonyl) methyl derivative (6) and 1,2-disubstituted hydrazine (7), respectively. The structures of the 1,2,4-triazine derivatives were confirmed by IR, 1H, 13C NMR, MS and elemental analyses. Anticancer activity of some 1,2,4-triazine derivatives (4-7) have been investigated. The results revealed that compounds 4a (IC50= 2.7μM), 5a (IC50= 1.5μM), and 5b (IC50= 3.9μM) show promising inhibitory growth efficacy compared to a standard antitumor drug (IC50= 4.6μM). These three compounds can be considered as potential agents against human hepatocellular carcinoma cell lines (HepG-2).

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