196801-10-2Relevant articles and documents
HheG, a halohydrin dehalogenase with activity on cyclic epoxides
Koopmeiners, Julia,Diederich, Christina,Solarczek, Jennifer,Vo?, Hauke,Mayer, Janine,Blankenfeldt, Wulf,Schallmey, Anett
, p. 6877 - 6886 (2017)
Halohydrin dehalogenases (HHDHs) are of biotechnological interest due to their promiscuous epoxide ring-opening activity with a set of negatively charged nucleophiles, enabling the formation of C-C, C-N, or C-O bonds. The recent discovery of HHDH-specific sequence motifs aided the identification of a large number of halohydrin dehalogenases from public sequence databases, enlarging the biocatalytic toolbox substantially. During the characterization of 17 representatives of these phylogenetically diverse enzymes, one HHDH, namely HheG from Ilumatobacter coccineus, was identified to convert cyclic epoxide substrates. The enzyme exhibits significant activity in the azidolysis of cyclohexene oxide and limonene oxide with turnover numbers of 7.8 and 44 s-1, respectively. As observed for other HHDHs, the cyanide-mediated epoxide ring-opening proceeded with lower rates. Wild-type HheG displays modest enantioselectivity, as the resulting azido- and cyanoalcohols of cyclohexene oxide ring-opening were obtained in 40% enantiomeric excess. These biocatalytic findings were further complemented by the crystal structure of the enzyme refined to 2.3 ?. Analysis of HheG's structure revealed a large open cleft harboring the active site. This is in sharp contrast to other known HHDH structures and aids in explaining the special substrate scope of HheG.
Cytochrome P450 catalyzed oxidative hydroxylation of achiral organic compounds with simultaneous creation of two chirality centers in a single C-H activation step
Roiban, Gheorghe-Doru,Agudo, Ruben,Reetz, Manfred T.
supporting information, p. 8659 - 8663 (2014/08/18)
Regio- and stereoselective oxidative hydroxylation of achiral or chiral organic compounds mediated by synthetic reagents, catalysts, or enzymes generally leads to the formation of one new chiral center that appears in the respective enantiomeric or diastereomeric alcohols. By contrast, when subjecting appropriate achiral compounds to this type of C-H activation, the simultaneous creation of two chiral centers with a defined relative and absolute configuration may result, provided that control of the regio-, diastereo-, and enantioselectivity is ensured. The present study demonstrates that such control is possible by using wild type or mutant forms of the monooxygenase cytochrome P450 BM3 as catalysts in the oxidative hydroxylation of methylcyclohexane and seven other monosubstituted cyclohexane derivatives.
Preparation of the stereoisomers of 2-cyanocycloalkanols by lipase-catalysed acylation
Forro, Eniko,Lundell, Katri,Fueloep, Ferenc,Kanerva, Liisa T.
, p. 3095 - 3099 (2007/10/03)
Enantiopure (1R,2R)-, (1S,2S)-, (1S,2R)- and (1R,2S)-2-cyanocyclopentanol and -cyclohexanol isomers were prepared through the Pseudomonas cepacia lipase-catalysed acetylation of the racemic cis and trans compounds with vinyl acetate in diisopropyl ether.
