| Abstract: | Appreciable amounts of amide are formed in the course of nitrile hydrolysis in the presence of recombinant nitrilase from Pseudomonas fluorescens EBC 191, depending on the α‐substituent and the reaction conditions. The ratio of the nitrilase and nitrile hydratase activities of the enzyme is profoundly influenced by the electronic and steric properties of the reactant. In general, amide formation increased when the α‐substituent was electron‐deficient; 2‐chloro‐2‐phenylacetonitrile, for example, afforded 89 % amide. We found, moreover, that (R)‐mandelonitrile was hydrolysed with 11 % of amide formation whereas 55 % amide was formed from the (S)‐enantiomer; a similar effect was found for the O‐acetyl derivatives. A mechanism that accomodates our results is proposed. |
