Enantioselective conversion of alpha-arylnitriles by Klebsiella oxytoca
- Publikations-Art
- Zeitschriftenbeitrag (peer-reviewed)
- Autoren
- Ewert, C., Lutz-Wahl, S., Fischer, L.
- Erscheinungsjahr
- 2008
- Veröffentlicht in
- Tetrahedron: Asymmetry
- Verlag
- Elsevier
- Band/Volume
- 22/19
- DOI
- 10.1016/j.tetasy.2008.11.014
- Seite (von - bis)
- 2573-2578
A new bacterial isolate Klebsiella oxytoca 38.1.2 with stereoselective nitrile hydratase activity against rac-2-phenylglycine nitrile, rac-2-phenylpropionitrile and rac-,andelonitrile was investigated. The cultivation conditions for growth and nitrile hydratase formation were studied. An intracellular (S)-enantioselective nitrile hydratase and a putative (S)-selective amidase were found to be induced in the presence of rac-2-phenylpropionitrile. The temperature dependence on the nantioselectivity of the nitrile hydratase active cells was studied in more detail for the biotransformation of rac-2-phenylpropionitrile and racmandelonitrile. By increasing the temperature from 15 °C to 37 °C, the apparent enantiomeric ratio of the conversion of rac-2-phenylpropionitrile to (S)-2-phenylpropionamide increased from 16 to 35 at nearly 50% conversion rate. rac-Mandelonitrile was converted to (S)-mandelamide with an enantiomeric excess of up to 95% in a 80% yield without further conversion to mandelic acid.