title: Towards catalyst compartimentation in combined chemo- and biocatalytic processes: immobilization of alcohol dehydrogenases for the diastereoselective reduction of a β-hydroxy ketone obtained from an organocatalytic aldol reaction.
abstract: The alcohol dehydrogenases (ADHs) from Lactobacillus kefir and Rhodococcus sp., which earlier turned out to be suitable for a chemoenzymatic one-pot synthesis with organocatalysts, were immobilized with their cofactors on a commercially available superabsorber based on a literature known protocol. The use of the immobilized ADH from L. kefir in the reduction of acetophenone as a model substrate led to high conversion (>95%) in the first reaction cycle, followed by a slight decrease of conversion in the second reaction cycle. A comparable result was obtained when no cofactor was added although a water rich reaction media was used. The immobilized ADHs also turned out to be suitable catalysts for the diastereoselective reduction of an organocatalytically prepared enantiomerically enriched aldol adduct, leading to high conversion, diastereomeric ratio and enantioselectivity for the resulting 1,3-diols. However, at a lower catalyst and cofactor amount being still sufficient for biotransformations with "free" enzymes the immobilized ADH only showed high conversion and >99% ee for the first reaction cycle whereas a strong decrease of conversion was observed already in the second reaction cycle, thus indicating a significant leaching effect of catalyst and/or cofactor.
authors.affiliation: Department of Chemistry and Pharmacy, University of Erlangen-Nürnberg, Henkestraße 42, 91054 Erlangen, Germany.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Rulli
authors.forename: Marcel
authors.initials: M
authors.lastname: Heidlindemann
authors.forename: Albrecht
authors.initials: A
authors.lastname: Berkessel
authors.forename: Werner
authors.initials: W
authors.lastname: Hummel
authors.forename: Harald
authors.initials: H
authors.lastname: Gröger
mesh_terms: D019840:2-Propanol / Q000378:metabolism; D000098:Acetophenones / Q000378:metabolism*; D000426:Alcohol Dehydrogenase / Q000378:metabolism*; D000447:Aldehydes / Q000737:chemistry / Q000378:metabolism*; D001426:Bacterial Proteins / Q000378:metabolism; D055162:Biocatalysis; D001709:Biotechnology; D003067:Coenzymes / Q000378:metabolism; D004800:Enzymes, Immobilized / Q000378:metabolism*; D007659:Ketones / Q000737:chemistry / Q000378:metabolism*; D007778:Lactobacillus / Q000201:enzymology; D012240:Rhodococcus / Q000201:enzymology; D013237:Stereoisomerism; D013379:Substrate Specificity
chemical_list: D000098:Acetophenones; D000447:Aldehydes; D001426:Bacterial Proteins; D003067:Coenzymes; D004800:Enzymes, Immobilized; D007659:Ketones; C116609:3-hydroxybutanal; D000426:Alcohol Dehydrogenase; D019840:2-Propanol; C038699:acetophenone
keywords: ADH; Alcohol; Alcohol dehydrogenase; Enzyme catalysis; Immobilization; NAD(+); NADH; NADP(+); NADPH; Reduction; alcohol dehydrogenase; nicotinamide adenine dinucleotide oxidized form; nicotinamide adenine dinucleotide phosphate oxidized form; nicotinamide adenine dinucleotide phosphate reduced form; nicotinamide adenine dinucleotide reduced form