Different strategies for stereoselective microbial preparation of various chiral aromatic compounds are described. Optically pure 2-methyl-3-phenyl-1-propanol, ethyl 2-methyl-3-phenylpropanoate, 2-methyl-3-phenylpropanal, 2-methyl-3-phenylpropionic acid and 2-methyl-3-phenylpropyl acetate have been prepared using different microbial biotransformations starting from different prochiral and/or racemic substrates. (S)-2-Methyl-3-phenyl-1-propanol and (S)-2-methyl-3-phenylpropanal were prepared by biotransformation of 2-methyl cinnamaldehyde using the recombinant strain Saccharomyces cerevisiae BY4741ΔOye2Ks carrying a heterologous OYE gene from Kazachstania spencerorum. (R)-2-Methyl-3-phenylpropionic acid was obtained by oxidation of racemic 2-methyl-3-phenyl-1-propanol with acetic acid bacteria. Kinetic resolution of racemic 2-methyl-3-phenylpropionic acid was carried out by direct esterification with ethanol using dry mycelia of Rhizopus oryzae CBS 112.07 in organic solvent, giving (R)-ethyl 2-methyl-3-phenylpropanoate as major enantiomer. Finally, (R,S)-2-methyl-3-phenylpropyl acetate was enantioselectively hydrolysed employing different bacteria and yeasts having cell-bound carboxylesterases with prevalent formation of (R)- or (S)-2-methyl-3-phenyl-1-propanol, depending on the strain employed.
|Titolo:||Complementary microbial approaches for the preparation of optically pure aromatic molecules|
|Parole Chiave:||Acetic acid bacteria; Enoate reductase; Esterase; Microbial biotransformation; Oxidation; Stereoselective|
|Settore Scientifico Disciplinare:||Settore CHIM/11 - Chimica e Biotecnologia delle Fermentazioni|
|Data di pubblicazione:||set-2013|
|Digital Object Identifier (DOI):||10.1007/s13213-012-0557-x|
|Appare nelle tipologie:||01 - Articolo su periodico|