Study on the Asymmetric Synthesis of Chiral 3,3,3‐Trifluoro‐2‐Hydroxypropanoic Acids by Lactate Dehydrogenase

Chiral 3,3,3‐trifluoro‐2‐hydroxypropanoic acid (3,3,3‐trifluorolactic acid, TFLA), which possesses two significant functional groups, is a versatile intermediate in pharmaceutical and material synthesis. A feasible strategy for producing both the enantiomers of chiral TFLAs involves reduction of the corresponding pyruvate using lactate dehydrogenases (LDHs). In this study, ldh genes encoding l ‐LDHs from animals and d / l ‐LDHs from lactic acid bacteria are cloned and all the recombinant LDHs are successfully expressed with a histidine tag in Escherichia coli BL21 (DE3). To achieve cofactor regeneration, a nicotinamide adenine dinucleotide regeneration system is constructed using formate dehydrogenase from Candida boidinii . Chiral TFLA is synthesized from 3,3,3‐trifluoro‐2‐oxopropionic acid (trifluoropyruvic acid, TFPy) with good yields and excellent stereoselectivity, catalyzed by lactate dehydrogenases and formate dehydrogenase. Under optimized biocatalytic conditions, highly active d ‐ Lm LDH from Leuconostoc mesenteroides and chicken l ‐LDH from Gallus are screened for their ability to completely convert 0.5  m TFPy to produce optically pure ( S )‐TFLA and ( R )‐TFLA with enantiomeric excess >99.5% within 6 h, respectively. Molecular docking simulations investigate the catalytic mechanisms of selected d ‐LDH and l ‐LDH, revealing their activity and stereoselectivity toward CF 3 ‐containing TFPy.