Trypsin-catalyzed Hydrolysis of N-Benzoyl-L-arginine Ethyl Ester at Low pH*

Biochemistry ◽  
1965 ◽  
Vol 4 (6) ◽  
pp. 1086-1091 ◽  
Author(s):  
James A. Stewart ◽  
Jerry E. Dobson
Keyword(s):  
Ethyl Ester ◽  
Low Ph ◽  
Hydrolysis Of

The hydrolysis of coumarin diethyl acetal and the lactonization of coumarinic acid ethyl ester. The partitioning of tetrahedral intermediates generated from independent sources

1979 ◽  
Vol 57 (17) ◽  
pp. 2260-2267 ◽  
Author(s):  
R. A. McClelland ◽  
R. Somani ◽  
A. J. Kresge
Keyword(s):  
Ethyl Ester ◽  
Acid Ester ◽  
Acid Ethyl Ester ◽  
Major Product ◽  
Low Ph ◽  
Diethyl Acetal ◽  
Acidic Solutions ◽  
Rate Determining Step ◽  
Hydrolysis Of ◽  
Tetrahedral Intermediates

The hydrolysis of coumarin diethyl acetal to coumarin proceeds via two detectable intermediates. A short-lived transient is observed in strongly acidic solutions (pH < 2.5); this is the oxocarbonium ion intermediate of the hydrolysis. That this cation can be detected suggests unusual stability, a fact which can be explained in terms of its pyrilium ion nature. A long-lived intermediate is also observed; kinetic and spectral evidence suggest that this is coumarinic acid ethyl ester. The lactonization of this ester shows a change in rate-determining step as the pH is varied. A corresponding change in products is found in the acetal hydrolysis, the coumarinic acid ester being the major product at high pH, with coumarin the major product at low pH. Both observations can be explained in terms of different modes of partitioning of cationic and neutral tetrahedral intermediates. Analysis in quantitative terms shows that the same tetrahedral intermediate is generated in the two different cases.

Synthesis of Normuramic Acid Carba Analog and Its Glycopeptide Derivative Resistant to β-Elimination Splitting of the Side Chain

2000 ◽  
Vol 65 (11) ◽  
pp. 1726-1736 ◽  
Author(s):  
Miroslav Ledvina ◽  
Radka Pavelová ◽  
Anna Rohlenová ◽  
Jan Ježek ◽  
David Šaman
Keyword(s):  
Ethyl Ester ◽  
Alkaline Hydrolysis ◽  
Benzyl Ester ◽  
Side Chain ◽  
Propanoic Acid ◽  
Hydrolysis Of

Carba analogs of normuramic acid, i.e., 3-(benzyl 2-acetamido-2,3-dideoxy-4,6-O-isopropylidene-α-D-glucopyranosid-3-yl)propanoic acid derivatives (nitrile or esters) 3a-3c were prepared by addition of radicals generated from benzyl 2-acetamido-2-deoxy-4,6-O-isopropylidene-3-O-[(methylsulfanyl)thiocarbonyl]- (2a) or -3-O-(phenoxythiocarbonyl)-α-D-glucopyranoside (2b) with Bu3SnH to acrylonitrile or acryl esters. Alkaline hydrolysis of ethyl ester 3c afforded 3-(benzyl 2-acetamido-2,3-dideoxy-4,6-O-isopropylidene-α-D-glucopyranosid-3-yl)propanoic acid (5). Coupling of acid 5 with L-2-aminobutanoyl-D-isoglutamine benzyl ester trifluoroacetate and subsequent deprotection of the intermediate 6 furnished N-[3-(2-acetamido-2,3-dideoxy-α-D-glucopyranosid-3-yl)propanoyl]-L-2-aminobutanoyl-D-isoglutamine (7).

Thermodynamics of the Hydrolysis of N-Acetyl-L-phenylalanine Ethyl Ester in Water and in Organic Solvents

1995 ◽  
Vol 99 (5) ◽  
pp. 1594-1601 ◽  
Author(s):  
Y. B. Tewari ◽  
M. M. Schantz ◽  
P. C. Pandey ◽  
M. V. Rekharsky ◽  
R. N. Goldberg
Keyword(s):  
Ethyl Ester ◽  
Organic Solvents ◽  
Hydrolysis Of

scholarly journals Dissociation of clathrin coats coupled to the hydrolysis of ATP: role of an uncoating ATPase.

1984 ◽  
Vol 99 (2) ◽  
pp. 734-741 ◽  
Author(s):  
W A Braell ◽  
D M Schlossman ◽  
S L Schmid ◽  
J E Rothman
Keyword(s):  
Atpase Activity ◽  
Atp Hydrolysis ◽  
Low Ph ◽  
Coated Vesicles ◽  
Magnesium Concentration ◽  
Cross Linking ◽  
Dependent Atpase ◽  
Event Triggering ◽  
Hydrolysis Of

ATP hydrolysis was used to power the enzymatic release of clathrin from coated vesicles. The 70,000-mol-wt protein, purified on the basis of its ATP-dependent ability to disassemble clathrin cages, was found to possess a clathrin-dependent ATPase activity. Hydrolysis was specific for ATP; neither dATP nor other ribonucleotide triphosphates would either substitute for ATP or inhibit the hydrolysis of ATP in the presence of clathrin cages. The ATPase activity is elicited by clathrin in the form of assembled cages, but not by clathrin trimers, the product of cage disassembly. The 70,000-mol-wt polypeptide, but not clathrin, was labeled by ATP in photochemical cross-linking, indicating that the hydrolytic site for ATP resides on the uncoating protein. Conditions of low pH or high magnesium concentration uncouple ATP hydrolysis from clathrin release, as ATP is hydrolyzed although essentially no clathrin is released. This suggests that the recognition event triggering clathrin-dependent ATP hydrolysis occurs in the absence of clathrin release, and presumably precedes such release.

Enantioselective Hydrolysis of a Schiff's Base of D,L-Phenylalanine Ethyl Ester in Water-Poor Media Via the Reaction Catalyzed with α-Chymotrypsin Immobilized on Hydrophilic Macroporous Gel Support

2000 ◽  
Vol 88 (1-3) ◽  
pp. 097-106 ◽  
Author(s):  
Yury N Belokon ◽  
Konstantin A Kochetkov ◽  
Fatima M Pleiva ◽  
Nikolai S Ikonnikov ◽  
Viktor I Maleev ◽  
...  
Keyword(s):  
Ethyl Ester ◽  
Enantioselective Hydrolysis ◽  
Schiff’S Base ◽  
Hydrolysis Of

The effect of calcium ions on the hydrolysis of benzoylarginine ethyl ester by porcine enteropepridase

1976 ◽  
Vol 452 (1) ◽  
pp. 161-164 ◽  
Author(s):  
R.J. Barns ◽  
R.G. Elmslie
Keyword(s):  
Ethyl Ester ◽  
Calcium Ions ◽  
Hydrolysis Of
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