Asymmetric bioreduction of keto groups of 4-and 5-Oxodecanoic acids/esters with a new carbonyl reductase

A novel carbonyl reductase from Serratia marcescens, SmCR, was successfully cloned and overexpressed in Escherichia coil. SmCR could catalyze the asymmetric reduction of long-chain keto acids/esters containing remote carbonyl groups, such as 4-oxo- and 5-oxodecanoic acids, yielding chiral gamma- and delta-decalactones with high en-antiopurity (up to 99% ee). This is the first report of enzymatic synthesis of (R)-gamma- and (R)-delta-decalactones starting from gamma-, delta-keto acids using free enzymes.