Enzyme-catalyzed synthesis or (R)-ketone-cyanohydrins and their hydrolysis to (R)-α-hydroxy-α-methyl-carboxylic acids
摘要:
(R)-Ketone-cyanohydrins (R)-2 are obtained with high enantioselectivity from aliphatic ketones 1 and HCN in organic solvents using (R)-oxynitrilase (EC 4.1.2.10) as catalyst. Acid catalyzed hydrolysis of the cyanohydrins (R)-2 affords the corresponding (R)-alpha-hydroxy-alpha-methyl-carboxylic acids (R)-3 without measurable racemization.
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
Approach to(R)- and (S)-ketone cyanohydrins using almond and apple meal as the source of (R)-oxynitrilase
作者:Eero Kiljunen、Liisa T. Kanerva
DOI:10.1016/s0957-4166(97)00110-9
日期:1997.5
The synthesis of aliphatic and aromatic (R)-ketone cyanohydrins through the addition of hydrogen cyanide to the corresponding ketones and the synthesis of the (S)-enantiomers through the kinetic resolution of racemic ketone cyanohydrins has been studied in the presence of almond or apple meal. Substrate tolerance of the (R)-oxynitrilases towards ketones ((RRC)-R-1-C-2=O) is highly restricted compared to that of structurally similar aldehydes, reactivity following the order of H>Me much greater than Et for R-2. In the case of aromatic methyl ketones reactivity difference (C6H5 much greater than p-Me-C6H4 for R-1) is notable. (C) 1997 Elsevier Science Ltd.