21080-62-6Relevant academic research and scientific papers
Microbial Baeyer-Villiger oxidation of 5α-steroids using Beauveria bassiana. A stereochemical requirement for the 11α-hydroxylation and the lactonization pathway
?wizdor, Alina,Panek, Anna,Milecka-Tronina, Natalia
, p. 44 - 52 (2014/03/21)
Beauveria bassiana KCH 1065, as was recently demonstrated, is unusual amongst fungal biocatalysts in that it converts C19 3-oxo-4-ene and 3β-hydroxy-5-ene as well as 3β-hydroxy-5α-saturated steroids to 11α-hydroxy ring-D lactones. The Baeyer-Villiger monooxygenase (BVMO) of this strain is distinguished from other enzymes catalyzing BVO of steroidal ketones by the fact that it oxidizes solely substrates with 11α-hydroxyl group. The current study using a series of 5α-saturated steroids (androsterone, 3α-androstanediol and androstanedione) has highlighted that a small change of the steroid structure can result in significant differences of the metabolic fate. It was found that the 3α-stereochemistry of hydroxyl group restricted "normal" binding orientation of the substrate within 11α-hydroxylase and, as a result, androsterone and 3α-androstanediol were converted into a mixture of 7β-, 11α- and 7α-hydroxy derivatives. Hydroxylation of androstanedione occurred only at the 11α-position, indicating that the 3-oxo group limits the alternative binding orientation of the substrate within the hydroxylase. Only androstanedione and 3α-androstanediol were metabolized to hydroxylactones. The study uniquely demonstrated preference for oxidation of equatorial (11α-, 7β-) hydroxyketones by BVMO from B. bassiana. The time course experiments suggested that the activity of 17β-HSD is a factor determining the amount of produced ring-D lactones. The obtained 11α-hydroxylactones underwent further transformations (oxy-red reactions) at C-3. During conversion of androstanedione, a minor dehydrogenation pathway was observed with generation of 11α,17β-dihydroxy-5α-androst-1-en-3-one. The introduction of C1C2 double bond has been recorded in B. bassiana for the first time.
Microbiological Transformations. Part 4. Microbiological Transformations of 5α-Androstan-17-ones and of 17a-Aza-D-homo-5α-androstan-17-ones with the Fungus Cunninghamella elegans
Crabb, Trevor A.,Saul, John A.,Williams, Roger O.
, p. 1041 - 1045 (2007/10/02)
The microbiological transformation of 5α-androstan-17-one, and the 3β-acetoxy- and 3α-hydroxy-derivatives, by Cunninghamella elegans is dominated by 1β,7-dihydroxylation or 7-monohydroxylation. 3α-Acetoxy-5α-androstan-17-one undergoes predominant 6β,11β-dihydroxylation. 17a-Aza-D-homo-5α-androstan-17-one and the 3α-acetoxy-derivative undergo predominant monohydroxylation at 6β or 7α, in contrast to the 3β-acetoxy-derivative which, although undergoing similar monohydroxylation, gives good yield of 9α-monohydroxylated products.
