title: Introducing an in situ capping strategy in systems biocatalysis to access 6-aminohexanoic acid.
abstract: The combination of two cofactor self-sufficient biocatalytic cascade modules allowed the successful transformation of cyclohexanol into the nylon-6 monomer 6-aminohexanoic acid at the expense of only oxygen and ammonia. A hitherto unprecedented carboxylic acid capping strategy was introduced to minimize the formation of the dead-end intermediate 6-hydroxyhexanoic acid. For this purpose, the precursor ε-caprolactone was converted in aqueous medium in the presence of methanol into the corresponding methyl ester instead of the acid. Hence, it was shown for the first time that esterases--specifically horse liver esterase--can perform the selective ring-opening of ε-caprolactone with a clear preference for methanol over water as the nucleophile.
authors.affiliation: Institut für Chemie, Organische und Bioorganische Chemie, University of Graz, Heinrichstrasse 28, 8010 Graz (Austria); Austrian Centre of Industrial Biotechnology (ACIB), Petersgasse 14, 8010 Graz (Austria).
authors.forename: Johann H
authors.initials: JH
authors.lastname: Sattler
authors.forename: Michael
authors.initials: M
authors.lastname: Fuchs
authors.forename: Francesco G
authors.initials: FG
authors.lastname: Mutti
authors.forename: Barbara
authors.initials: B
authors.lastname: Grischek
authors.forename: Philip
authors.initials: P
authors.lastname: Engel
authors.forename: Jan
authors.initials: J
authors.lastname: Pfeffer
authors.forename: John M
authors.initials: JM
authors.lastname: Woodley
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Kroutil
mesh_terms: D015119:Aminocaproic Acid / Q000737:chemistry / Q000378:metabolism*; D000818:Animals; D055162:Biocatalysis; D003511:Cyclohexanols / Q000737:chemistry / Q000378:metabolism*; D004950:Esterases / Q000737:chemistry / Q000378:metabolism*; D006736:Horses; D008099:Liver / Q000201:enzymology; D015394:Molecular Structure
chemical_list: D003511:Cyclohexanols; D004950:Esterases; D015119:Aminocaproic Acid
keywords: bioorganic chemistry; enzyme catalysis; ester formation; lactone opening; nylon-6