The Effect of Organic Solvents and Other Parameters on Trypsin-Catalyzed Hydrolysis of Nα[alpha]-Benzoyl-arginine-p-nitroanilide. A Project-Oriented Biochemical Experiment

2001 ◽  
Vol 78 (11) ◽  
pp. 1535 ◽  
Author(s):  
L. C. Correia ◽  
A. C. Bocewicz ◽  
S. A. Esteves ◽  
M. G. Pontes ◽  
L. M. Versieux ◽  
...  
Keyword(s):  
Organic Solvents ◽  
Biochemical Experiment ◽  
Hydrolysis Of

scholarly journals Influence of Water Activity on Protease Adsorbed on Biochar in Organic Solvents

2017 ◽  
Vol 6 (4) ◽  
pp. 96 ◽  
Author(s):  
Hidetaka Noritomi ◽  
Jumpei Nishigami ◽  
Nobuyuki Endo ◽  
Satoru Kato ◽  
Katsumi Uchiyama
Keyword(s):  
Thermal Stability ◽  
Catalytic Activity ◽  
Organic Solvents ◽  
Water Activity ◽  
Initial Rate ◽  
Butyl Ester ◽  
Nitrogen Atmosphere ◽  
Bamboo Charcoal ◽  
Influence Of Water ◽  
Hydrolysis Of

We have found that the organic solvent-resistance of Alpha-chymotrypsin (Alpha-CT) is enhanced by adsorbing Alpha-CT onto bamboo charcoal powder (BCP), which is obtained by pyrolyzing bamboo waste under nitrogen atmosphere, and is markedly dependent on the thermodynamic water activity (aw) in organic solvents. When BCP-adsorbed　Alpha-CT was immersed in acetonitrile at an appropriate water activity, it effectively enhanced the transesterification of N-acetyl-L-tyrosine ethyl ester (N-Ac-Tyr-OEt) with n-butanol (BuOH) to produce N-acetyl-L-tyrosine butyl ester (N-Ac-Tyr-OBu), compared to the hydrolysis of N-Ac-Tyr-OEt with water to give N-acetyl-L-tyrosine (N-Ac-Tyr-OH). When the water activity was 0.28, the initial rate of transesterification catalyzed by BCP-adsorbed Alpha-CT was about sixty times greater than that catalyzed by free Alpha-CT. Regarding the reaction selectivity which is defined as a ratio of the initial rate of transesterification to that of hydrolysis, BCP-adsorbed α-CT was much superior to free Alpha-CT. The catalytic activity of BCP-adsorbed Alpha-CT was markedly dependent on the reaction temperature. Furthermore, concerning the thermal stability at 50 oC, the half-life of BCP-adsorbed Alpha-CT exhibited 3.8-fold, compared to that of free Alpha-CT.

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 Polysilsesquioxanes Through Base-Catalyzed Redistribution of Oligohydridosiloxanes

2000 ◽  
Vol 628 ◽  
Author(s):  
Kamyar Rahimian ◽  
Roger A. Assink ◽  
David P. Lang ◽  
Douglas A. Loy
Keyword(s):  
Organic Solvents ◽  
Sol Gel ◽  
Base Catalysts ◽  
Ceramic Precursors ◽  
Sol Gel Synthesis ◽  
Low K ◽  
Hydrolysis Of

Organopolysilsesquioxanes have recently gained much interest as materials for low-K dielectrics [1], ceramic precursors [2] and photoresists [3]. Typical sol-gel synthesis of polysilsesquioxanes involves the hydrolysis of organotricholorosilanes and/or organotrialkoxysilanes in the presence of acid or base catalysts and organic solvents. However, under sol-gel conditions most organotrialkoxysilanes do not afford silsesquioxane gels. This limits the range of organic functionalities that can be introduced into these hybrid organicinorganic materials.

scholarly journals Performance of Various Organic Solvents as Reaction Media in Plant Oil Lipolysis with Plant Lipase

REAKTOR ◽  
2018 ◽  
Vol 18 (2) ◽  
pp. 71
Author(s):  
Astri Nur Istyami ◽  
Tatang Hernas Soerawidjaja ◽  
Tirto Prakoso ◽  
Tri Ari Penia Kresnowati
Keyword(s):  
Fatty Acids ◽  
Organic Solvent ◽  
Organic Solvents ◽  
Process Condition ◽  
Plant Oil ◽  
Plant Lipase ◽  
Reaction Media ◽  
Hydrolysis Of ◽  
Product Degradation ◽  
Plant Latex

Fatty acids are intermediate substances in synthesis of oleochemical products. Enzymatic technology of fatty acids production (also known as lipolysis) is now developing as potential substitution for the conventional production of fatty acid, i.e. thermal hydrolysis of triglyceride. It offers more economical process condition, low energy consumption, and minimal product degradation compared to the conventional process. This research aims to evaluate performance of various organic solvents as reaction media in lipolysis with plant latex lipase. Organic solvents observed were chloroform, n-hexane, diethyl ether, benzene, acetone, ethanol, methanol, n-heptane, and isooctane. Analysis of each organic solvent effect on lipolysis was described based on solvents properties. Conversion of lipolysis with organic solvents is 0,10-1,25 times fold compared to conversion of non-solvent lipolysis. We suggest that dielectric constant and viscosity are the two main organic solvent properties affecting lipase performance in lipolysis. Overall, n-hexane, n-heptane, and isooctane are recommended to be used as reaction media in lipolysis with plant lipase because their effects to degree of lipolysis are positive.  Keywords: lipolysis; lipase; organic solvent; frangipani

Effects of organic solvents on immobilized enzyme catalyses. Chymotrypsin immobilized on Sephadex

1980 ◽  
Vol 58 (23) ◽  
pp. 2633-2640 ◽  
Author(s):  
Diana H. Pliura ◽  
J. Bryan Jones
Keyword(s):  
Enzyme Activity ◽  
Organic Solvents ◽  
Immobilized Enzyme ◽  
Reaction Medium ◽  
Butyl Alcohol ◽  
Native Enzyme ◽  
Tert Butyl ◽  
Tert Butyl Alcohol ◽  
Catalytic Rate ◽  
Hydrolysis Of

The esterolytic activities of native chymotrypsin (CT) and immobilized CT-Sephadex have been studied in the presence of up to 20% of the organic solvents methanol, ethanol, 2-propanol, tert-butyl alcohol, dioxane, or DMSO. The general cosolvent-induced inhibition of the native enzyme was attenuated for immobilized CT. Most noticeably, the apparent catalytic rate constants for the CT-Sephadex-catalyzed hydrolysis of N-acetyl-L-tyrosine ethyl ester were invariant over the 2–20% dioxane concentration range surveyed. In contrast, the activity of the native enzyme in 20% dioxane was only 3% the activity recorded in the absence of cosolvent. Increasing the hydrophobic character of the protic cosolvents destabilized the native enzyme but stabilized CT-Sephadex. Both native and immobilized CT displayed remarkable stability in 20% aqueous DMSO [Formula: see text]. At least part of the DMSO-induced inhibition of native CT and CT-Sephadex was offset by increasing the apparent pH of the reaction medium. The altered kinetic patterns for CT-Sephadex are best explained by the effects of diffusional limitations on the apparent enzyme activity. The best compromise solvent for preparative applications of CT-Sephadex was found to be tert-butyl alcohol.

Improving the Industrial Production of 6-APA: Enzymatic Hydrolysis of Penicillin G in the Presence of Organic Solvents

2003 ◽  
Vol 19 (6) ◽  
pp. 1639-1642 ◽  
Author(s):  
O. Abian ◽  
C. Mateo ◽  
G. Fernandez-Lorente ◽  
J.M. Guisan ◽  
R. Fernandez-Lafuente
Keyword(s):  
Enzymatic Hydrolysis ◽  
Organic Solvents ◽  
Industrial Production ◽  
Penicillin G ◽  
Hydrolysis Of

Recent Studies on the Application of Enzymes in the Synthesis of Polyesters

1990 ◽  
Vol 218 ◽  
Author(s):  
Cary J. Morrow ◽  
Eugenia M. Brazwell ◽  
Dianela Filos ◽  
Juanita Mercure ◽  
Rosemary Romero ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Ambient Temperature ◽  
Organic Solvents ◽  
Pancreatic Lipase ◽  
Bound Water ◽  
Optically Active ◽  
Porcine Pancreatic Lipase ◽  
Dibenzyl Ether ◽  
High Boiling Solvent ◽  
Hydrolysis Of

AbstractEnzyme-catalyzed preparation of polymers offers several potentially valuable advantages over the usual polymerization procedures. This paper summarizes our successful use of lipase-catalyzed polycondensations to prepare both a series of achiral [AA-BB]x polyesters from bis(2,2,2- trichloroethyl) alkanedioates and diols and of an optically active, epoxy-substituted polyester having a stereochemical purity estimated to be greater than 96%, from racemic bis(2,2,2-trichloroethyl) trans-3,4-epoxyhexanedioate and 1,4-butanediol. All of the reactions were carried out at ambient temperature in anhydrous, low to intermediate polarity, organic solvents such as ether, THF, 2-ethoxyethyl ether, dibenzyl ether, o-dichlorobenzene, or methylene choride, using porcine pancreatic lipase (PPL) as the catalyst. The molecular weight achieved by the polycondensation is limited by accumulation of the trihaloethanol that forms as the reaction progresses, probably because it frees enzyme-bound water permitting hydrolysis of the polymer to occur. This problem has been alleviated by using a high boiling solvent and removing the alcohol by placing the re'action mixture under vacuum.

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