26549-25-7Relevant academic research and scientific papers
Biocatalytic Racemization Employing TeSADH: Substrate Scope and Organic Solvent Compatibility for Dynamic Kinetic Resolution
Pop?oński, Jaros?aw,Reiter, Tamara,Kroutil, Wolfgang
, p. 763 - 768 (2018/02/27)
Racemization in combination with a kinetic resolution is the base for a dynamic kinetic resolution (DKR). Biocatalytic racemization was successfully performed for a broad scope of sec-alcohols by employing a single alcohol dehydrogenase (ADH) variant from Thermoanaerobacter pseudoethanolicus (formerly T. ethanolicus; TeSADH W110A I86A C295A). The catalyst employed as a lyophilized whole cell preparation or cell free extract, which tolerated various non-water miscible organic solvents under micro-aqueous or two-phase conditions, whereby cyclohexane and n-hexane suited best. Various concepts for combining the enzymatic racemization with an enzymatic kinetic resolution to achieve overall a bis-enzymatic DKR were evaluated. A proof of concept showed a successful DKR with racemization in aqueous phase combined with acylation in the organic phase.
ALKANE OXIDATION BY MODIFIED HYDROXYLASES
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Paragraph 0323; 0324, (2016/02/16)
This invention relates to modified hydroxylases. The invention further relates to cells expressing such modified hydroxylases and methods of producing hydroxylated alkanes by contacting a suitable substrate with such cells.
In vitro double oxidation of n-heptane with direct cofactor regeneration
Mueller, Christina A.,Akkapurathu, Beneeta,Winkler, Till,Staudt, Svenja,Hummel, Werner,Groeger, Harald,Schwaneberg, Ulrich
supporting information, p. 1787 - 1798 (2013/07/19)
A novel concept for the direct oxidation of cycloalkanes to the corresponding cyclic ketones in a one-pot synthesis in water with molecular oxygen as sole oxidizing agent was reported recently. Based on this concept we have developed a new strategy for the double oxidation of n-heptane to enable a biocatalytic resolution for the direct synthesis of heptanone and (R)-heptanols in a one-pot reaction. The bicatalytic cascade employs an NADH driven P450 BM3 monooxygenase variant (WTNADH, 19A12NADH or CM1 NADH) and an (S)-enantioselective alcohol dehydrogenase (RE-ADH). In the initial step n-heptane is hydroxylated under consumption of NADH to produce (R/S)-heptanol. In the second oxidation step the (S)-heptanol enantiomers are transformed to the corresponding ketones, reducing and thereby regenerating the cofactor. Characterization of initial hydroxylation step revealed high turnover frequencies (TOF) of up to 600 min-1, as well as high coupling efficiencies using NADH as cofactor (up to 44%). In the cascade reaction a nearly 2-fold improved product formation was achieved, compared to the single hydroxylation reaction. The total product concentration reached 1.1 mM, corresponding to a total turnover number (TTN) of 2500. Implementation of an additional cofactor regeneration system (D-glucose/glucose dehydrogenase) enabled a further enhancement in product formation with a total product concentration of 1.8 mM and a TTN of 3500. Copyright
Microbial asymmetric CH oxidations of simple hydrocarbons: A novel monooxygenase activity of the topsoil microorganism Bacillus megaterium
Adam, Waldemar,Lukacs, Zoltan,Saha-Moeller, Chantu R.,Weckerle, Bernhard,Schreier, Peter
, p. 2923 - 2926 (2007/10/03)
A Bacillus megaterium strain was isolated from topsoil by a selective screening procedure with allylbenzene as xenobiotic substrate. It is demonstrated for the first time, from analytical-scale experiments, that this microorganism hydroxylates a variety of simple n-alkanes (hexane through nonane) and cycloalkanes (cyclohexane and cyclooctane) to afford optically active alcohols in up to 99% enantiomeric excess (ee). In the case of the n-alkanes, the ω-1, ω-2 and ω-3 regioisomers were obtained. This enzymatic activity is unprecedented for Bacillus megaterium strains and is generally rarely observed in bacteria.
