American Chemical Society
op7b00194_si_001.pdf (1.18 MB)

Identification of a Robust Carbonyl Reductase for Diastereoselectively Building syn-3,5-Dihydroxy Hexanoate: a Bulky Side Chain of Atorvastatin

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journal contribution
posted on 2017-07-05, 00:00 authored by Xu-Min Gong, Gao-Wei Zheng, You-Yan Liu, Jian-He Xu
t-Butyl-6-cyano-(3R,5R)-dihydroxyhexanoate is an advanced chiral precursor for the synthesis of the side chain pharmacophore of cholesterol-lowering drug atorvastatin. Herein, a robust carbonyl reductase (LbCR) was newly identified from Lactobacillus brevis, which displays high activity and excellent diastereoselectivity toward bulky t-butyl 6-cyano-(5R)-hydroxy-3-oxo-hexanoate (7). The engineered Escherichia coli cells harboring LbCR and glucose dehydrogenase (for cofactor regeneration) were employed as biocatalysts for the asymmetric reduction of substrate 7. As a result, as much as 300 g L–1 of water-insoluble substrate was completely converted to the corresponding chiral diol with >99.5% de in a space–time yield of 351 g L–1 d–1, indicating a great potential of LbCR for practical synthesis of the very bulky and bi-chiral 3,5-dihydroxy carboxylate side chain of best-selling statin drugs.