Bioreductive preparation of ACE inhibitors precursor (R)-2-hydroxy-4-phenylbutanoate esters: Recent advances and future perspectives

Optically active (R)-2-hydroxy-4-phenylbutanoate esters ((R)-HPBE) are key precursors for the production of angiotension-converting enzyme (ACE) inhibitors, which are important prescriptive drugs for preventing the formation of angiotensin II and lowering the blood pressure. The biocatalytic asymmetric reduction of ethyl 2-oxo-4phenylbutanoate (OPBE) to (R)-HPBE with carbonyl reductases has several advantageous attributes, including high enantioselectivity, mild reaction condition, high catalytic efficiency, and environmental benignity. An increasing number of OPBE reductases have been discovered owing to the drastic achievements in genomics, screening and evolution technologies, and process engineering. The potential of (R)-HPBE production process has also been intensively evaluated. This review covers recent progress on the bioreductive preparation of (R)-HPBE, especially on various screening approaches for the identification of OPBE reductases and their characterization.