Stereoselective reduction of β-keto esters by Geotrichum candidum

Add time:07/18/2019    Source:sciencedirect.com

A key chiral intermediate S(−)-4-chloro-3-hydroxybutanoic acid, methyl ester 2 was made in high optical purity by the stereoselective reduction of 4-chloro-3-oxobutanoic acid methyl ester 1 by cell suspensions of Geotrichum candidum SC 5469. A reaction yield of 95% and optical purity of 96% was obtained for 2 by glucose-, acetate-, or glycerol-grown cells (10% w/v) of G. candidum SC 5469. Substrate was used at 10 mg ml−1 concentration. The optical purity of 2 was increased to 99% by heat treatment of cell suspensions (55°C for 30 min) prior to conducting bioreduction of 1 at 28°C.Glucose-grown cells of G. candidum SC 5469 have also catalyzed the stereoselective reduction of ethyl-, isopropyl-, and tertiary-butyl esters of 4-chloro-3-oxobutanoic acid and methyl- and ethyl esters of 4-bromo-3-oxobutanoic acid. A reaction yield of > 85% and optical purity of > 94% were obtained. NADP-dependent oxidoreductase responsible for the stereoselective reduction of β-keto esters of 4-chloro- and 4-bromo-3-oxobutanoic acid was purified 100-fold. The molecular weight of the purified enzyme is 950,000. The purified oxidoreductase was immobilized on Eupergit C and used to catalyze the reduction of 1 to 2. The cofactor NADP required for the reduction reaction was regenerated by glucose dehydrogenase.

We also recommend Trading Suppliers and Manufacturers of 4-Oxobutanoic acid ethyl ester (cas 10138-10-0). Pls Click Website Link as below: cas 10138-10-0 suppliers

Prev:4-(Ethoxycarbonyl) phenyl-1-amino-oxobutanoic acid–chitosan complex as a new matrix for silver nanocomposite film: Preparation, characterization and antibacterial activity
Next:Synthesis of methyl 2-exo-cyano-3-exo-phenyl-5,6-endo (or exo)-epoxybicyclo[2.2.1]heptane-2-endo-carboxylates in enantiomerically pure form.)