title: Production of a doubly chiral compound, (4R,6R)-4-hydroxy-2,2,6-trimethylcyclohexanone, by two-step enzymatic asymmetric reduction.
abstract: A practical enzymatic synthesis of a doubly chiral key compound, (4R,6R)-4-hydroxy-2,2,6-trimethylcyclohexanone, starting from the readily available 2,6,6-trimethyl-2-cyclohexen-1,4-dione is described. Chirality is first introduced at the C-6 position by a stereoselective enzymatic hydrogenation of the double bond using old yellow enzyme 2 of Saccharomyces cerevisiae, expressed in Escherichia coli, as a biocatalyst. Thereafter, the carbonyl group at the C-4 position is reduced selectively and stereospecifically by levodione reductase of Corynebacterium aquaticum M-13, expressed in E. coli, to the corresponding alcohol. Commercially available glucose dehydrogenase was also used for cofactor regeneration in both steps. Using this two-step enzymatic asymmetric reduction system, 9.5 mg of (4R,6R)-4-hydroxy-2,2,6-trimethylcyclohexanone/ml was produced almost stoichiometrically, with 94% enantiomeric excess in the presence of glucose, NAD(+), and glucose dehydrogenase. To our knowledge, this is the first report of the application of S. cerevisiae old yellow enzyme for the production of a useful compound.
authors.affiliation: Department of Bioscience, Fukui Prefectural University, Matsuoka-cho, Fukui 910-1195, Japan. masaru@fpu.ac.jp
authors.forename: Masaru
authors.initials: M
authors.lastname: Wada
authors.forename: Ayumi
authors.initials: A
authors.lastname: Yoshizumi
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Noda
authors.forename: Michihiko
authors.initials: M
authors.lastname: Kataoka
authors.forename: Sakayu
authors.initials: S
authors.lastname: Shimizu
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Takagi
authors.forename: Shigeru
authors.initials: S
authors.lastname: Nakamori
mesh_terms: D003512:Cyclohexanones / Q000737:chemistry* / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D042843:Glucose 1-Dehydrogenase; D005948:Glucose Dehydrogenases / Q000378:metabolism; D009252:NADPH Dehydrogenase / Q000235:genetics* / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics; D013237:Stereoisomerism; D013379:Substrate Specificity
chemical_list: D003512:Cyclohexanones; D005948:Glucose Dehydrogenases; D042843:Glucose 1-Dehydrogenase; D009252:NADPH Dehydrogenase; C438457:3,3,5-trimethylcyclohexanone