- Highly enantioselective bioreduction of prochiral ketones by stem and germinated plant of Brassica oleracea variety italica
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An eco-friendly and environmentally benign asymmetric reduction of a broad range of prochiral ketones employing Brassica oleracea variety italica (stems and germinated plant) as a novel biocatalyst was developed. It was found that B. oleracea variety italica could be used effectively for enantioselective bioreduction in aqueous medium with moderate to excellent chemical yield and enantiomeric excess (ee). This process is more efficient and generates less waste than conventional chemical reagents or microorganisms. Both R- and S-configurations were obtained by these asymmetric reactions. The best ee were achieved for pyridine derivatives (92-99%). The ee in germinated plant reactions were significantly higher than those of stem reactions. The low cost and the easy availability of these biocatalysts suggest their possible use for large scale preparations of important chiral alcohols.
- Mohammadi, Mehdi,Yousefi, Maryam,Habibi, Zohreh
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experimental part
p. 328 - 336
(2012/03/11)
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- Bioreduction of prochiral ketones by growing cells of Lasiodiplodia theobromae: Discovery of a versatile biocatalyst for asymmetric synthesis
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Growing cells of the phytopathogen fungus Lasiodiplodia theobromae in potato dextrose broth have shown their potential for the stereoselective bioreduction of different prochiral aromatic and aliphatic ketones. Optically active alcohols were obtained under mild reaction conditions in high conversions (up to 90%) and moderate to excellent enantioselectivity (35-≥99% ee) depending on the ketone structure. Prelog alcohols were isolated, except in the bioreduction of cyclohexylmethylketone and octan-2-one where anti-Prelog alcohols were obtained.
- Barros-Filho, Bartholomeu A.,Nunes, Fatima M.,de Oliveira, Maria da Conceicao F.,Lemos, Telma L.G.,de Mattos, Marcos C.,de Gonzalo, Gonzalo,Gotor-Fernandez, Vicente,Gotor, Vicente
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experimental part
p. 37 - 40
(2010/12/18)
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- Lentinus strigellus: a new versatile stereoselective biocatalyst for the bioreduction of prochiral ketones
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Growing cells of the basiodiomycete Lentinus strigellus in potato-dextrose broth have been used for the first time as a biocatalyst in the stereoselective reduction of aromatic and aliphatic ketones. Most of the aromatic ketones were converted into the corresponding optically active alcohols in up to >99% enantiomeric excess under very mild reaction conditions. Among the aliphatic ketones tested, 2-octanone was enzymatically reduced by this microorganism to enantiopure (S)-2-octanol with almost complete conversion.
- Barros-Filho, Bartholomeu A.,de Oliveira, Maria da Conceicao F.,Lemos, Telma L.G.,de Mattos, Marcos C.,Gonzalo, Gonzalo de,Gotor-Fernandez, Vicente,Gotor, Vicente
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experimental part
p. 1057 - 1061
(2009/10/02)
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- Sequential kinetic resolution catalyzed by halohydrin dehalogenase
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(Chemical Equation Presented) A sequential kinetic resolution catalyzed by halohydrin dehalogenase was employed for the synthesis of two valuable enantiopure building blocks. Resolution of methyl 4-chloro-3-hydroxybutanoate methylester ((R,S)-2) with use of a Trp249Phe mutant of halohydrin dehalogenase yielded methyl 4-cyano-3-hydroxybutanoate methylester ((S)-4) with 96.8% ee (40% yield) and (S)-2 with 95.2% ee (41% yield). This reaction is carried out in aqueous solution under mild conditions and provides access to a useful statin side-chain building block.
- Elenkov, Maja Majeric,Tang, Lixia,Hauer, Bernhard,Janssen, Dick B.
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p. 4227 - 4229
(2007/10/03)
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- Industrialization of the Microbial Resolution of Chiral C3 and C4 Synthetic Units: From a Small Beginning to a Major Operation, a Personal Account
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This account describes the research and development of the microbial resolution of chiral C3 and C4 synthetic units through to the production stage. These chiral C3 and C4 synthetic units are mainly used for the production of various pharmaceuticals, new materials such as liquid crystals, chiral polymers, and natural compounds as well as in basic chemical research. The research started in 1983 and the industrial plant was built in 1994. The development is still ongoing and is being broadened to include C4 chiral units, chiral propylene glycol, and so on. This project started as simple research on the activated sludge from an epichlorohydrin plant and evolved through many events and much research to an industrial production. We describe the various implications and the flow of events in the research and development through to the production of these chiral C3 and C4 synthetic units.
- Kasai, Naoya,Suzuki, Toshio
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p. 437 - 455
(2007/10/03)
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- Stereochemical Control in Microbial Reduction. 8. Stereochemical Control in Microbial Reduction of β-Keto Esters
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Stereochemistry of the reduction of β-keto esters with bakers' yeast is controlled by the addition of a certain α,β-unsaturated carbonyl compound (or its reduced form).Glucose also exerts the same effect.The additives tend to shift the stereochemistry of the reduction toward the production of D-hydroxy ester.Namely, methyl 3-oxopentanoate and ethyl 3-oxo-6-heptenoate were reduced to the corresponding D-hydroxy esters with excellent stereoselectivities and chemical yields.The enones are supposed to inhibit the enzymes that produce the L-hydroxy ester, whereas glucose plays a role to activate the enzymes that produce the D-hydroxy ester.
- Nakamura, Kaoru,Kawai, Yasushi,Oka, Shinzaburo,Ohno, Atsuyoshi
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p. 875 - 879
(2007/10/02)
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- A NEW CHIRAL HOST COMPOUND 10,10'-DIHYDROXY-9,9'-BIPHENANTHRYL. OPTICAL RESOLUTION OF PROPIONIC ACID DERIVATIVES, BUTYRIC ACID DERIVATIVES, AND 4-HYDROXYCYCLOPENT-2-EN-1-ONE DERIVATIVES BY COMPLEXATION
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Optically active 10,10'-dihydroxy-9,9'-biphenanthryl was designed as a new chiral host compound for optical resolution of guest compounds, and was found to be wery effective for resolution of the title guest compounds.
- Toda, Fumio,Tanaka, Koichi
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p. 1807 - 1810
(2007/10/02)
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- Biotransformation in Organic Synthesis: Applications of Yeast Reduction in the Synthesis of 3,5-Dihydroxy Esters of High Optical Purity
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All four stereoisomers of methyl 6-(p-chlorophenylthio)-3,5-dihydroxyhexanoate have been synthesised by a route in which the key introduction of chirality was effected by an appropriate yeast reduction.
- Christen, Markus,Crout, David H. G.
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p. 264 - 266
(2007/10/02)
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- STEREOCHEMICAL CONTROL IN MICROBIAL REDUCTION 4. EFFECT OF CULTIVATION CONDITIONS ON THE REDUCTION OF β-KETO ESTERS BY METHYLOTROPHIC YEASTS.
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When β-keto esters are reduced by methanol grown yeast, drastic shift of the enantiomer excess of the products toward D-isomer formation is caused compared with those by glucose grown cells.
- Ushio, Kazutoshi,Inouye, Kiyoko,Nakamura, Kaoru,Oka, Shinzaburo,Ohno, Atsuyoshi
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p. 2657 - 2660
(2007/10/02)
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- STEREOCHEMICAL CONTROL OF MICROBIAL REDUCTION. 2. REDUCTION OF β-KETO ESTERS BY IMMOBILIZED BAKERS' YEAST
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Ketones in β-keto esters are reduced asymmetrically by immobilized bakers' yeast.The configuration and the enantiomer excess of the products are dramatically changed by the entrapment of yeast cells in dense polyurethane matrices.
- Nakamura, Kaoru,Higaki, Masato,Ushio, Kazutoshi,Oka, Shinzaburo,Ohno, Atsuyoshi
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p. 4213 - 4216
(2007/10/02)
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