Details
| Originalsprache | Englisch |
|---|---|
| Seiten (von - bis) | 1007-1016 |
| Seitenumfang | 10 |
| Fachzeitschrift | Tetrahedron: Asymmetry |
| Jahrgang | 4 |
| Ausgabenummer | 5 |
| Publikationsstatus | Veröffentlicht - 5 Mai 1993 |
| Extern publiziert | Ja |
Abstract
Chiral resolutions of racemic 3-hydroxy esters were performed in organic phases with lipases from Pseudomonas cepacia, Chromobacterium viscosum and Porcine pancreas. The reaction conditions have been optimized with 3-hydroxy octanoic acid methyl ester. Different organic solvents have been tested showing a tendentious correlation with the hydrophobicity of the solvents expressed as log P. The reaction time was shortened six fold by using irreversible acylating agents. We have found solvent type, lipase type and acylating agent acting as tools for changing the enantioselectivity. Lipase from Pseudomonas cepacia was lyophilized at different pH and the influence of the amount of water added was investigated, resulting in the highest activity at the pH optimum and a denaturation of the lipase above 1 % water (w/wlipase). The water activity was measured on-line with a humidity sensor. Water activities greater than 0.4 led to a decrease in enantioselectivity and reaction rate. In the optimized system the resolutions of other 3-hydroxy esters were tested. Aliphatic compounds reacted with lower enantioselectivity, only the substrates could be isolated in high enantiomeric purity. In contrast, aromatic 3-hydroxy esters were acylated by lipases with high stereoselectivity. A model of the active site of lipase from Pseudomonas sp. explained these experimental observations.
ASJC Scopus Sachgebiete
- Chemische Verfahrenstechnik (insg.)
- Katalyse
- Chemie (insg.)
- Physikalische und Theoretische Chemie
- Chemie (insg.)
- Organische Chemie
- Chemie (insg.)
- Anorganische Chemie
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in: Tetrahedron: Asymmetry, Jahrgang 4, Nr. 5, 05.05.1993, S. 1007-1016.
Publikation: Beitrag in Fachzeitschrift › Artikel › Forschung › Peer-Review
}
TY - JOUR
T1 - Factors affecting the lipase catalyzed transesterification reactions of 3-hydroxy esters in organic solvents.
AU - Bornscheuer, Uwe
AU - Herar, Andrea
AU - Kreye, Lars
AU - Wendel, Volker
AU - Capewell, Andreas
AU - Meyer, Hartmut H.
AU - Scheper, Thomas
AU - Kolisis, Fragiskos N.
PY - 1993/5/5
Y1 - 1993/5/5
N2 - Chiral resolutions of racemic 3-hydroxy esters were performed in organic phases with lipases from Pseudomonas cepacia, Chromobacterium viscosum and Porcine pancreas. The reaction conditions have been optimized with 3-hydroxy octanoic acid methyl ester. Different organic solvents have been tested showing a tendentious correlation with the hydrophobicity of the solvents expressed as log P. The reaction time was shortened six fold by using irreversible acylating agents. We have found solvent type, lipase type and acylating agent acting as tools for changing the enantioselectivity. Lipase from Pseudomonas cepacia was lyophilized at different pH and the influence of the amount of water added was investigated, resulting in the highest activity at the pH optimum and a denaturation of the lipase above 1 % water (w/wlipase). The water activity was measured on-line with a humidity sensor. Water activities greater than 0.4 led to a decrease in enantioselectivity and reaction rate. In the optimized system the resolutions of other 3-hydroxy esters were tested. Aliphatic compounds reacted with lower enantioselectivity, only the substrates could be isolated in high enantiomeric purity. In contrast, aromatic 3-hydroxy esters were acylated by lipases with high stereoselectivity. A model of the active site of lipase from Pseudomonas sp. explained these experimental observations.
AB - Chiral resolutions of racemic 3-hydroxy esters were performed in organic phases with lipases from Pseudomonas cepacia, Chromobacterium viscosum and Porcine pancreas. The reaction conditions have been optimized with 3-hydroxy octanoic acid methyl ester. Different organic solvents have been tested showing a tendentious correlation with the hydrophobicity of the solvents expressed as log P. The reaction time was shortened six fold by using irreversible acylating agents. We have found solvent type, lipase type and acylating agent acting as tools for changing the enantioselectivity. Lipase from Pseudomonas cepacia was lyophilized at different pH and the influence of the amount of water added was investigated, resulting in the highest activity at the pH optimum and a denaturation of the lipase above 1 % water (w/wlipase). The water activity was measured on-line with a humidity sensor. Water activities greater than 0.4 led to a decrease in enantioselectivity and reaction rate. In the optimized system the resolutions of other 3-hydroxy esters were tested. Aliphatic compounds reacted with lower enantioselectivity, only the substrates could be isolated in high enantiomeric purity. In contrast, aromatic 3-hydroxy esters were acylated by lipases with high stereoselectivity. A model of the active site of lipase from Pseudomonas sp. explained these experimental observations.
UR - http://www.scopus.com/inward/record.url?scp=0027256398&partnerID=8YFLogxK
U2 - 10.1016/S0957-4166(00)80145-7
DO - 10.1016/S0957-4166(00)80145-7
M3 - Article
AN - SCOPUS:0027256398
VL - 4
SP - 1007
EP - 1016
JO - Tetrahedron: Asymmetry
JF - Tetrahedron: Asymmetry
SN - 0957-4166
IS - 5
ER -