Publications by authors named "Cheng-Li He"
Biocatalytic Thionation of Epoxides for Enantioselective Synthesis of Thiiranes.
Angew Chem Int Ed Engl
December 2022
Article Synopsis
- Researchers are focusing on enhancing enzymatic methods for creating valuable molecules in synthetic chemistry and pharmaceuticals, particularly chiral thiiranes, due to limited existing synthesis methods.
- A new biocatalytic thionation approach has been developed, which uses a specially engineered halohydrin dehalogenase (HHDH) to selectively open epoxide rings with thiocyanate and transform them into thiiranes.
- The engineered HHDH enabled successful production of various thiiranes with significant yield and enantioselectivity, showcasing the method's efficiency through large-scale synthesis and further useful transformations.
We report the discovery of an unusual halohydrin dehalogenase, HHDHamb, that can work under relatively low acidic conditions and extremely low temperatures for the bio-nitration of epoxides using nitrite as a nitrating agent. The bio-nitration strategy exhibits high chemo-, regio-, and enantioselectivity, catalyzing the kinetic resolution of various epoxides to enantiopure β-nitroalcohols with nitro-bearing stereocenters in up to 41 % isolated yield and >99 % enantiomeric excess (ee). Additionally, the bio-nitration method displays a high reaction efficiency and can be performed on a gram scale.
View Article and Find Full Text PDFThe main targets of this work were to evaluate the antioxidative properties of flavonoids in Jerusalem artichoke ( L.) leaves and quantitatively determine their contents. 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2-azino-bis (3-ethylbenzothiazoline)-6-sulphonic acid (ABTS) and hydroxyl free radicals scavenging assays were performed to determine their antioxidative capacities.
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