Production of Chiral (S)-2-Phenyl-1-Propanol by Enantioselective Biocatalysts

Enantioselective production of (S)-2-phenyl-1-propanol is important as in order to be applied in industry, a high degree of optical purity is required. Besides organocatalysts and metal complexes, biocatalysts can be used for its synthesis in their isolated form or as whole-cell biocatalysts, both of which have various advantages and disadvantages. In this research, Saccharomyces cerevisiae, as a whole-cell biocatalyst, and recombinant horse-liver alcohol dehydrogenase (ADH), as an isolated enzyme, were investigated in terms of their activity, kinetics and enantioselectivity. In the case of yeast, therate of cofactor regeneration was twice that of substrate conversion, moreover, the biocatalyst Saccharomyces cerevisiae can be characterised by substrate-limited kinetics and low  nantioselectivity. In contrast, the isolated enzyme recombinant horse-liver ADH exhibited biphasic kinetics and cofactor regeneration was the rate-limiting step. The outstanding enantioselectivity of recombinant horse-liver ADH renders it a promising catalyst for the purpose of this synthesis.