title: An enzyme cascade synthesis of ε-caprolactone and its oligomers.
abstract: Poly-ε-caprolactone (PCL) is chemically produced on an industrial scale in spite of the need for hazardous peracetic acid as an oxidation reagent. Although Baeyer-Villiger monooxygenases (BVMO) in principle enable the enzymatic synthesis of ε-caprolactone (ε-CL) directly from cyclohexanone with molecular oxygen, current systems suffer from low productivity and are subject to substrate and product inhibition. The major limitations for such a biocatalytic route to produce this bulk chemical were overcome by combining an alcohol dehydrogenase with a BVMO to enable the efficient oxidation of cyclohexanol to ε-CL. Key to success was a subsequent direct ring-opening oligomerization of in situ formed ε-CL in the aqueous phase by using lipase A from Candida antarctica, thus efficiently solving the product inhibition problem and leading to the formation of oligo-ε-CL at more than 20 g L(-1) when starting from 200 mM cyclohexanol. This oligomer is easily chemically polymerized to PCL.
authors.affiliation: Institute of Biochemistry, Dept. of Biotechnology & Enzyme Catalysis, Greifswald University, Felix-Hausdorff-Strasse 4, 17487 Greifswald (Germany).
authors.forename: Sandy
authors.initials: S
authors.lastname: Schmidt
authors.forename: Christian
authors.initials: C
authors.lastname: Scherkus
authors.forename: Jan
authors.initials: J
authors.lastname: Muschiol
authors.forename: Ulf
authors.initials: U
authors.lastname: Menyes
authors.forename: Till
authors.initials: T
authors.lastname: Winkler
authors.forename: Werner
authors.initials: W
authors.lastname: Hummel
authors.forename: Harald
authors.initials: H
authors.lastname: Gröger
authors.forename: Andreas
authors.initials: A
authors.lastname: Liese
authors.forename: Hans-Georg
authors.initials: HG
authors.lastname: Herz
authors.forename: Uwe T
authors.initials: UT
authors.lastname: Bornscheuer
mesh_terms: D000426:Alcohol Dehydrogenase / Q000737:chemistry / Q000378:metabolism*; D006899:Mixed Function Oxygenases / Q000737:chemistry / Q000378:metabolism*; D015394:Molecular Structure; D011091:Polyesters / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D011091:Polyesters; C016240:polycaprolactone; D006899:Mixed Function Oxygenases; D000426:Alcohol Dehydrogenase
keywords: Baeyer-Villiger monooxygenases; cascade reactions; enzyme catalysis; polymer synthesis; ε-caprolactone