Asymmetric acyloin condensation catalyzed by phenylpyruvate decarboxylase

Cells obtained from growth of Achromobacter eurydice , Pseudomonas aromatica and Pseudomonas putida on l -phenylalanine containing medium catalyzed the enzymatic acyloin condensation of phenylpyruvic acid 1 and acetaldehyde 2 by phenylpyruvate decarboxylase to produce 3-hydroxy-1-phenyl-2-butanone 3 . The acyloin condensation by Achromobacter eurydice and P. aromatica was stereoselective, providing the 3 R enantiomer 3a with enantiomeric excess (ee) of 95% and 84%, respectively. A partially purified enzyme was prepared from the cell free extract of Achromobacter eurydice. The acyloin product 3a was obtained in 45% yield with an ee of 91% by using this partially purified preparation of phenylpyruvate decarboxylase.