A new (R)-hydroxynitrile lyase from Prunus mume: asymmetric synthesis of cyanohydrins
作者:Samik Nanda、Yasuo Kato、Yasuhisa Asano
DOI:10.1016/j.tet.2005.08.105
日期:2005.11
A new hydroxynitrile lyase (HNL) was isolated from the seed of Japanese apricot (Prunus mume). The enzyme has similar properties with HNL isolated from other Prunus species and is FAD containing enzyme. It accepts a large number of unnatural substrates (benzaldehyde and its variant) for the addition of HCN to produce the corresponding cyanohydrins in excellent optical and chemical yields. A new HPLC
Synthesis of Aliphatic and α-Halogenated Ketone Cyanohydrins with the Hydroxynitrile Lyase from <i>Manihot esculenta</i>
作者:Johannes Diebler、Jan von Langermann、Annett Mell、Martin Hein、Peter Langer、Udo Kragl
DOI:10.1002/cctc.201300965
日期:2014.4
The potential of the hydroxynitrilelyasefromManihotesculenta towards ketone substrates was investigated. It was observed that the length of the aliphatic chain is a key parameter for the conversion of aliphatic, non‐branched ketones. Smaller substrates are readily converted with high enantioselectivites, but the elongation of the chain length causes a significant loss in enzyme activity. For a
(R)-Oxynitrilase catalyzed synthesis of (R)-ketone cyanohydrins
作者:Franz Effenberger、Stephan Heid
DOI:10.1016/0957-4166(95)00391-6
日期:1995.12
enantioselective addition of HCN to ethyl alkyl ketones 1 in diisopropyl ether yielding (R)-ethyl alkyl ketone cyanohydrins (R)-2, which are hydrolyzed under acid catalysis to give the α-hydroxy acids (R)-3. This (R)-oxynitrilase also catalyzes the enantioselective addition in aqueous citrate buffer (50 mM, pH 4.0), as demonstrated for the preparation of (R)-methyl alkyl ketone cyanohydrins (R)-5 which are obtained
Enzyme catalysed formation of (S)-cyanohydrins derived from aldehydes and ketones in a biphasic solvent system
作者:Herfried Griengl、Norbert Klempier、Peter Pöchlauer、Michael Schmidt、Nongyuan Shi、Antonina A Zabelinskaja-Mackova
DOI:10.1016/s0040-4020(98)00901-6
日期:1998.11
By employing a vigorously stirred two phase system aqueous buffer/organic solvent and using the hydroxynitrilelyase from Hevea brasiliensis as biocatalyst enantiopure (S)-cyanohydrins from aliphatic, unsaturated, aromatic and heteroaromatic aldehydes and methyl alkyl and methyl phenyl ketones are obtained in high yield and in general 98–99% enantiomeric excess.
undertaken. When Lewis acid catalysis is dominant, a significantly positive reaction constant is observed, whereas reactions dominated by Lewisbasecatalysis give much smaller reaction constants. [Ti(salen)O}2] was found to show the highest degree of Lewis acid catalysis, whereas two [VO(salen)X] (X=EtOSO3 or NCS) complexes both displayed lower degrees of Lewis acid catalysis. In the case of reactions