Stereospecific Biotransformation of (±) Phenylethyl Propionate by Cell Cultures of Peganum harmala L.

The enzymatic potential of the cultured plant cells can be employed for bioconversion purposes. Plant enzymes are able to catalyze regio- and stereo-specific reactions, and therefore can be applied for the production of desired substances. The biotransformation of foreign substrates with suspension cells of Peganum harmala was tested with (±) phenylethyl propionate. The callus cultures of Peganum harmala were established from cotyledons, and healthy suspensions grown using Murashige and Skoog medium. In order to investigate the specificities of the hydrolysis, (-) and (+) phenylethyl propionate isomers were added to the cultures. The phenylethyl propionate isomers were converted to their corresponding alcohols. The two isomers showed different rates of conversion during the first 24 hours after feeding. These cultures were able to hydrolyse specifically the propionate group in (±) phenylethyl propionate. It was found that the cultured cells of P. harmala have the ability to hydrolyse the racemic phenylethyl propionate stereoselectively.