2189-83-5Relevant articles and documents
A Peroxygenase from Chaetomium globosum Catalyzes the Selective Oxygenation of Testosterone
Kiebist, Jan,Schmidtke, Kai-Uwe,Zimmermann, J?rg,Kellner, Harald,Jehmlich, Nico,Ullrich, René,Z?nder, Daniel,Hofrichter, Martin,Scheibner, Katrin
, p. 563 - 569 (2017)
Unspecific peroxygenases (UPO, EC 1.11.2.1) secreted by fungi open an efficient way to selectively oxyfunctionalize diverse organic substrates, including less-activated hydrocarbons, by transferring peroxide-borne oxygen. We investigated a cell-free approach to incorporate epoxy and hydroxyl functionalities directly into the bulky molecule testosterone by a novel unspecific peroxygenase (UPO) that is produced by the ascomycetous fungus Chaetomium globosum in a complex medium rich in carbon and nitrogen. Purification by fast protein liquid chromatography revealed two enzyme fractions with the same molecular mass (36 kDa) and with specific activity of 4.4 to 12 U mg?1. Although the well-known UPOs of Agrocybe aegerita (AaeUPO) and Marasmius rotula (MroUPO) failed to convert testosterone in a comparative study, the UPO of C. globosum (CglUPO) accepted testosterone as substrate and converted it with total turnover number (TTN) of up to 7000 into two oxygenated products: the 4,5-epoxide of testosterone in β-configuration and 16α-hydroxytestosterone. The reaction performed on a 100 mg scale resulted in the formation of about 90 % of the epoxide and 10 % of the hydroxylation product, both of which could be isolated with purities above 96 %. Thus, CglUPO is a promising biocatalyst for the oxyfunctionalization of bulky steroids and it will be a useful tool for the synthesis of pharmaceutically relevant steroidal molecules.
Unambiguous assignment of 13C NMR signals in epimeric 4,5-epoxy-3-oxo-steroids assisted by X-ray diffraction and Gauge Invariant Atomic Orbitals calculation of absolute isotropic shieldings
Labra-Vazquez, Pablo,Galano, Annia,Romero-Avila, Margarita,Flores-Alamo, Marcos,Iglesias-Arteaga, Martin A.
, p. 107 - 125 (2013/09/12)
Complete assignments of the 13C signals of diastereomeric 4,5-epoxy-3-oxo steroids based on a combination of 1D and 2D NMR techniques are described The assignments were corroborated or corrected by calculation of the absolute isotropic 13C NMR shieldings using the Gauge Invariant Atomic Orbitals (GIAO) method at B3LYP/6-31+G(d,p) level. ARKAT-USA, Inc.
Highly efficient epoxidation of unsaturated steroids using magnesium bis(monoperoxyphthalate) hexahydrate
Carvalho, Jo?o F.S.,Silva, M. Manuel Cruz,Sá e Melo, M. Luisa
experimental part, p. 2773 - 2781 (2009/08/15)
Fast generation of epoxides from the corresponding homoallylic and allylic steroidal olefins was developed by using magnesium bis(monoperoxyphthalate) hexahydrate (MMPP) as oxidant suspended in acetonitrile (CH3CN) at reflux temperature. The protocol involves the use of a safe readily available oxidant along with an easy work-up, which renders the process very efficient. Selective 4,5- and 5,6-epoxidations of steroids are reported. Among them, highly stereoselective epoxidation of Δ5-B-nor-cholestanes was achieved. Moreover, the method is chemoselective for the 5,6-position and can be applied to the epoxidation of ring-A enones.