MICROBIAL TRANSFORMATIONS OF FERULIC ACID BY SACCHAROMYCES-CEREVISIAEAND PSEUDOMONAS-FLUORESCENS

Saccharomyces cerevisiae (dry baker's yeast) and Pseudomonas fluoresce ns were used to convert trans-ferulic acid into 4-hydroxy-3-methoxysty rene in 96 and 89% yields, respectively. The metabolites were isolated by solid-phase extraction and analyzed by thin-layer chromatography a nd high-performance liquid chromatography. The identities of the metab olites were determined by H-1- and C-13-nuclear magnetic resonance spe ctroscopy and by mass spectrometry. The mechanism of the decarboxylati on of ferulic acid was investigated by measuring the degree and positi on of deuterium incorporated into the styrene derivative from D2O by m ass spectrometry and by both proton and deuterium nuclear magnetic res onance spectroscopies. Resting cells of baker's yeast reduced ferulic acid to 4-hydroxy-3-methoxyphenylpropionic acid in 54% yield when incu bations were under an argon atmosphere.