89299-86-5Relevant articles and documents
Accessing Enantiopure Epoxides and Sulfoxides: Related Flavin-Dependent Monooxygenases Provide Reversed Enantioselectivity
Heine, Thomas,Scholtissek, Anika,Hofmann, Sarah,Koch, Rainhard,Tischler, Dirk
, p. 199 - 209 (2019/11/13)
Enantiopure organic compounds are of major importance for the chemical and pharmaceutical industry. Flavin-dependent group E monooxygenases, composed of monooxygenase and reductase, are known to perform epoxidation of substituted alkenes as well as sulfoxidation in a regio- and enantioselective fashion. Group E is divided into styrene monooxygenases (SMO) and indole monooxygenases (IMO). Hitherto mainly SMOs have been characterized. In this study, we assayed 31 monooxygenases from both types, while 23 of which showed activity. They almost exclusively produced (S)-styrene oxide at high enantiomeric excess with maximum activities of 0.73 μmol min?1 mg?1 (kcat=0.54 s?1). In case of sulfoxidation, we found that the enantioselectivity is contrary between both types. IMOs preferably produce the (S)-enantiomer while SMOs have a tendency to produce the (R)-enantiomer. Sequence analysis and molecular docking of substrates allowed identifying fingerprint motives: SMO N46-V48-H50-Y73-H76-S96 and IMO S46-Q48-M50-V/I73-I76-A96. These form an essential part of the active site while the loop (AS44-51) interacts with the co-substrate and other amino acids direct the substrate. The motives clearly distinguish group E monooxygenases and define the enantioselectivity and thus direct biotechnological applications. Two-hour biotransformations with several sulfides in conjunction with upscale experiments (10 and 100 mg scale) resulted in the identification of promising candidates for the realization of biocatalytic processes.
A novel homochiral metal-organic framework with an expanded open cage based on (: R)-3,3′-bis(6-carboxy-2-naphthyl)-2,2′-dihydroxy-1,1′-binaphthyl: synthesis, X-ray structure and efficient HPLC enantiomer separation
Tanaka, Koichi,Kawakita, Tomohiro,Morawiak, Maja,Urbanczyk-Lipkowska, Zofia
, p. 487 - 493 (2019/01/21)
A new homochiral metal-organic framework (MOF) with an expanded open cage based on the (R)-3,3′-bis(6-carboxy-2-naphthyl)-2,2′-dihydroxy-1,1′-binaphthyl ligand was synthesized and utilized as a novel chiral stationary phase for high-performance liquid chromatography. Twelve racemates including sec-alcohols, sulfoxides, epoxides, lactone, 1,3-dioxolan-2-one, and oxazolidinone were used as analytes for evaluating the separation properties of the chiral-MOF-packed column. Experimentally, the homochiral MOF offered good molecular recognition ability, which suggests good prospects for the application of chiral MOFs as stationary phases for enantioseparation.
Stereoselective sulfoxidation catalyzed by achiral Schiff base complexes in the presence of serum albumin in aqueous media
Tang, Jie,Yao, Pengfei,Huang, Fuping,Luo, Meiyi,Wei, Yi,Bian, Hedong
supporting information, p. 1700 - 1707 (2017/11/17)
Four coordination complexes ML derived from an achiral Schiff base ligand (H2L = 2,2′-[(1,2-ethanediyl)bis(nitrilopropylidyne)]bisphenol) have been synthesized and characterized. A method is described for the enantioselective oxidation of a series of aryl alkyl sulfides using the coordination complexes in the presence of serum albumins (SAs) in an aqueous medium at ambient temperature. The mixture of metal complexes with serum albumins is useful for inducing asymmetric catalysis. The complex, albumin source and substrate influence stereoselective sulfoxidation. At optimal pH with the appropriate oxidant, some of ML/SA systems are identified as very efficient catalysts, giving the corresponding sulfoxides in excellent chemical yield (up to 100%) and good enantioselectivity (up to 94% ee) in certain cases. UV–visible spectroscopic data provide evidence that stronger binding between the complex and serum albumin lead to higher enantioselectivity.
