Enantioselective Esterification Of (±)-Menthol With Butyric Anhydride By Chemically Modified Candida Rugosa Lipase

Commercial lipase from Candida rugosa was chemically modified with the aim to improve its catalytic properties in organic solvents. The chemical modifiers, aldehydes and monomethoxy polyethylene glycols, were covalently linked to the lysine residues at the surface of the enzyme. Enzymatic enantio...

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Main Author: Jasmani, Halila
Format: Thesis
Language:English
English
Published: 2003
Subjects:
Online Access:http://psasir.upm.edu.my/id/eprint/11622/
http://psasir.upm.edu.my/id/eprint/11622/1/FSAS_2003_10.pdf
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author Jasmani, Halila
author_facet Jasmani, Halila
author_sort Jasmani, Halila
building UPM Institutional Repository
collection Online Access
description Commercial lipase from Candida rugosa was chemically modified with the aim to improve its catalytic properties in organic solvents. The chemical modifiers, aldehydes and monomethoxy polyethylene glycols, were covalently linked to the lysine residues at the surface of the enzyme. Enzymatic enantioselective esterification of racemic menthol in organic solvents using butyric anhydride as acylating agent was performed with the chemically modified lipases. Different degrees of modification, organic solvents, reaction temperatures and water activity were examined for the influence on the percent yield and enantioselective formation of (-)-menthyl butyrate. The percent yield increased as the degree of modification increased but decreased slightly for the highest degree of modification. Organic solvents with log P values above 2.5 gave higher yield, however high enantioselectivity was obtained in all the organic solvents tested. The enantioselectivity towards (-)-menthol decreased considerably as the reaction temperature was increased. Enzyme derivatives exhibited better activity and enantioselectivity at high aw. The alkylated lipases showed higher thermal, solvent
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institution Universiti Putra Malaysia
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language English
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publishDate 2003
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spelling upm-116222024-06-24T03:31:53Z http://psasir.upm.edu.my/id/eprint/11622/ Enantioselective Esterification Of (±)-Menthol With Butyric Anhydride By Chemically Modified Candida Rugosa Lipase Jasmani, Halila Commercial lipase from Candida rugosa was chemically modified with the aim to improve its catalytic properties in organic solvents. The chemical modifiers, aldehydes and monomethoxy polyethylene glycols, were covalently linked to the lysine residues at the surface of the enzyme. Enzymatic enantioselective esterification of racemic menthol in organic solvents using butyric anhydride as acylating agent was performed with the chemically modified lipases. Different degrees of modification, organic solvents, reaction temperatures and water activity were examined for the influence on the percent yield and enantioselective formation of (-)-menthyl butyrate. The percent yield increased as the degree of modification increased but decreased slightly for the highest degree of modification. Organic solvents with log P values above 2.5 gave higher yield, however high enantioselectivity was obtained in all the organic solvents tested. The enantioselectivity towards (-)-menthol decreased considerably as the reaction temperature was increased. Enzyme derivatives exhibited better activity and enantioselectivity at high aw. The alkylated lipases showed higher thermal, solvent 2003-05 Thesis NonPeerReviewed text en http://psasir.upm.edu.my/id/eprint/11622/1/FSAS_2003_10.pdf Jasmani, Halila (2003) Enantioselective Esterification Of (±)-Menthol With Butyric Anhydride By Chemically Modified Candida Rugosa Lipase. Masters thesis, Universiti Putra Malaysia. Enantioselective catalysis Lipase Esterification English
spellingShingle Enantioselective catalysis
Lipase
Esterification
Jasmani, Halila
Enantioselective Esterification Of (±)-Menthol With Butyric Anhydride By Chemically Modified Candida Rugosa Lipase
title Enantioselective Esterification Of (±)-Menthol With Butyric Anhydride By Chemically Modified Candida Rugosa Lipase
title_full Enantioselective Esterification Of (±)-Menthol With Butyric Anhydride By Chemically Modified Candida Rugosa Lipase
title_fullStr Enantioselective Esterification Of (±)-Menthol With Butyric Anhydride By Chemically Modified Candida Rugosa Lipase
title_full_unstemmed Enantioselective Esterification Of (±)-Menthol With Butyric Anhydride By Chemically Modified Candida Rugosa Lipase
title_short Enantioselective Esterification Of (±)-Menthol With Butyric Anhydride By Chemically Modified Candida Rugosa Lipase
title_sort enantioselective esterification of (±)-menthol with butyric anhydride by chemically modified candida rugosa lipase
topic Enantioselective catalysis
Lipase
Esterification
url http://psasir.upm.edu.my/id/eprint/11622/
http://psasir.upm.edu.my/id/eprint/11622/1/FSAS_2003_10.pdf