Phase Diagrams to Evaluate the Opportunity for Enantiomeric Enrichment of Some Nonracemic Mixtures of Amino Acid Benzyl Esters by Crystallization as p-Toluenesulfonate Salts

2017 ◽  
Vol 21 (11) ◽  
pp. 1752-1757 ◽  
Author(s):  
Cristiano Bolchi ◽  
Francesco Bavo ◽  
Marco Pallavicini
Keyword(s):  
Amino Acid ◽  
Phase Diagrams ◽  
Enantiomeric Enrichment ◽  
Benzyl Esters

scholarly journals E64 [trans-epoxysuccinyl-l-leucylamido-(4-guanidino)butane] analogues as inhibitors of cysteine proteinases: investigation of S2 subsite interactions

1994 ◽  
Vol 299 (2) ◽  
pp. 389-392 ◽  
Author(s):  
B J Gour-Salin ◽  
P Lachance ◽  
M C Magny ◽  
C Plouffe ◽  
R Ménard ◽  
...  
Keyword(s):  
Amino Acid ◽  
Cathepsin B ◽  
Benzyl Ester ◽  
Amide Proton ◽  
Side Chain ◽  
Cysteine Proteinases ◽  
Enzyme Substrate ◽  
Amide Derivatives ◽  
Benzyl Esters ◽  
S2 Subsite

A number of epoxysuccinyl amino acid benzyl esters (HO-Eps-AA-OBzl) and benzyl amides (HO-Eps-AA-NHBzl) (where AA represents amino acid) were synthesized as analogues of E64, a naturally occurring inhibitor of cysteine proteinases. These inhibitors were designed to evaluate if selectivity for cathepsin B could be achieved by varying the amino acid on the basis of known substrate specificity. Contrary to the situation with substrates, it was found that variation of the amino acid in the E64 analogues does not lead to major changes in the kinetic parameter kinac./Ki and that the specificity of these analogues does not parallel that observed for substrates. This is particularly true in the case of the benzyl ester derivatives where the deviation from substrate-like behaviour is more important than with the benzyl amide derivatives. The results suggest that the amide proton of the benzyl amide group in HO-Eps-AA-NHBzl interacts in the S2 subsite in both cathepsin B and papain and contributes to increase the potency of these inhibitors. The kinetic data also suggest that differences in the orientation of the C alpha-C beta bond of the side chain in the S2 subsite of the enzyme might explain the differences between substrate and E64 analogue specificities. This hypothesis is supported by the fact that the order of inactivation rates with chloromethane inhibitors (which are believed to be good models of enzyme-substrate interactions) is indeed very similar to that observed with the corresponding amidomethylcoumarin substrates. In conclusion, the information available from S2-P2 interactions with substrates cannot be used to enhance the selectivity of the E64 analogues in a rational manner.

Comparative acidic cleavage experiments with methyl-substituted benzyl esters of amino acids

1967 ◽  
Vol 20 (10) ◽  
pp. 2243 ◽  
Author(s):  
FHC Stewart
Keyword(s):  
Amino Acids ◽  
Acetic Acid ◽  
Amino Acid ◽  
Solid Phase ◽  
Hydrogen Bromide ◽  
Solid Phase Peptide Synthesis ◽  
Amino Acid Derivatives ◽  
Methyl Substitution ◽  
Benzyl Esters ◽  
Layer Chromatography

The action of trifluoroacetic acid and hydrogen bromide in acetic acid, respectively, on the benzyl, p-methylbenzyl, 2,4,6-trimethylbenzyl, and penta-methylbenzyl esters of some amino acid derivatives has been investigated by thin-layer chromatography. Methyl substitution greatly enhances the lability of the ester groups. The possible bearing of the results on solid-phase peptide synthesis is discussed.

Specific water-soluble substrates for chymotrypsin: Attempts for compensating diminished P1-S1 interactions

1988 ◽  
Vol 53 (11) ◽  
pp. 2884-2889 ◽  
Author(s):  
Volker Schellenberger ◽  
Ute Schellenberger ◽  
Hans-Dieter Jakubke
Keyword(s):  
Amino Acid ◽  
Methyl Esters ◽  
Water Soluble ◽  
Amino Acid Residues ◽  
Substrate Properties ◽  
Ester Moiety ◽  
Benzyl Esters ◽  
Peptide Esters ◽  
Acyl Donors ◽  
Positively Charged

N-Maleyl-L-amino acid and peptide esters were synthesized and employed as substrates for α-chymotrypsin. From the kcat/KM values can be suggested that benzyl esters are significantly better substrates than the appropriate methyl esters. Further improvement in the substrate properties results from the introduction of the p-nitrobenzyl ester moiety. The choline ester of benzyloxycarbonyl-L-phenylalanine with the highest kcat/KM value confirmed the P1' leaving group specificity for positively charged residues. From the kinetic data can be concluded that acyl donors with high kcat/KM values, which are useful in kinetically controlled enzymatic peptide synthesis, need not contain aromatic amino acid residues in the P1 position.

scholarly journals One-step preparation of enantiopure l- or d-amino acid benzyl esters avoiding the use of banned solvents

Amino Acids ◽  
2017 ◽  
Vol 49 (5) ◽  
pp. 965-974 ◽  
Author(s):  
Cristiano Bolchi ◽  
Francesco Bavo ◽  
Marco Pallavicini
Keyword(s):  
Amino Acid ◽  
One Step ◽  
Benzyl Esters

Phase diagrams and phase structure of theN-octanoyl-L-glutamic acid oligomer benzyl esters-CHCl3 systems

1994 ◽  
Vol 272 (6) ◽  
pp. 692-703
Author(s):  
T. Uehara ◽  
H. Hirata ◽  
H. Okabayashi ◽  
K. Taga ◽  
T. Yoshida ◽  
...  
Keyword(s):  
Glutamic Acid ◽  
Phase Diagrams ◽  
Phase Structure ◽  
Benzyl Esters

Phase Diagrams of Mixtures of Diastereomeric Salts ofN-Acyl Amino Acid-Type Surfactants and Separation of Enantiomers

2004 ◽  
Vol 108 (32) ◽  
pp. 12204-12209 ◽  
Author(s):  
Akio Ohta ◽  
Yoshitoki Hata ◽  
Yusuke Mizuno ◽  
Tsuyoshi Asakawa ◽  
Shigeyoshi Miyagishi
Keyword(s):  
Amino Acid ◽  
Phase Diagrams ◽  
Amino Acid Type ◽  
Separation Of Enantiomers ◽  
Acid Type ◽  
Diastereomeric Salts
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