Microbial hydroxylation of steroids. 8. Incubation of Cn halo- and other substituted steroids with Cn hydroxylating fungi

Abstract

A series of C-21 substituted progesterone derivatives (R = F, CI, Br, CH,) has been prepared, and incubated the C-21 hydroxylating fungus A. niger. No biotransformation was observed where R = Cl, Br, or CH,, but a minor amount of hydroxylation occurred at an unidentified site where R = F. Two C-1lP substituted progesterone derivatives (R = F, OH) were converted to the corresponding C-11 ketone by the C-1 l a hydroxylator R. stolonifer, but a C-11P hydroxylator (C. lunata) was unable to perform a similar transformation with a C -l l a hydroxy substrate. C. lunata hydroxylated a C-1 I P fluoro substrate at C-14a and C-21 in low yield. C-7a and -7P-hydroxy androst-4-ene-3.17-diones were prepared and incubated with C-7P hydroxylating (R. stolonifer) and C-7u hydroxylating (M. griseocyanus) fungi respectively. No ketone formation was observed. Similarly, the C-60 hydroxylator R. arrhizus was unable to transform a C-6a-hydroxy substrate or C-6a-or C-613-hydroxy-B-norsteroids. No oxidation at halogen was observed for any of the substrates used. I3C-I9F coupling constants for 1 lp-fluoroprogesterone suggest the presence of through space interactions between fluorine and both C-18 and C-19. Introduction for hydroxylation, but has little effect in cases The widespread use of organohalides .in both where the favoured hydroxylation Site is remote industry and medicine has led to concern about from C,. Similarly, the metabolism of a fluorogibtheir toxic and/or carcinogenic effects (1). This in berellin derivative by Gibberella fugikuroi octurn stimulated research into their metabolic fate, curred largely independently of the Presence of which has indicated that, in many cases, bioactiva-fluorine (71, although the same group (8) found that tion of organohalides by a cytochrome p-450 de-Aspergillus aLienaceous could not produce an opendant rnixed-function oxygenase enzyme is a fluoro analog of avenaciolide when given the corkey step in their degradation, leading in some responding fluorinated Precursors. instances to the formation of toxicologically significant metabolites (2-4). Possible oxidative routesResults and discussion which have been considered (5) for this degradationThe substrates were prepared as described in the include hydroxylation at saturated carbon, oxida-Experimental. The use of tetraethyl tin (9) to tion of the halogen to a hypervalent state, and produce 21-methylprogesterone (le) from the acid epoxidation of C=C bonds. In this study, we have chloride of 8 is preferable to the existing methods utilized halosteroids, and fungi known to hydrox-(10, 11) using diethyl cadmium. The halosteroids ylate steroids at specific sites, in order to investi-were prepared by unexceptional procedures. The gate the first of these proposed modes of degrada-synthesis of 1 lp-fluoroprogesterone (3a) proceedtion.ed via the 9a-bromo compound 9 (12); we were Previous work with fluorosteroids and a series of unable to reproduce reports of the direct producfungi by the Oxford group (6) has demonstrated tion of 3a by reaction of 1la-...

Biotransformation of Testosterone by Ulocladium Chartarum Mrc 72584

“…The NMR spectrum of 5 had characteristic resonances at δ H 3.53 ppm (1H, m) and δ C 74.21 ppm, indicating the presence of a 7β-hydroxyl group. 6 The 13 C NMR spectrum of 5 showed a downfield shift for C-8 (Δ 7.08 ppm) while there was a γ-gauche upfield shift for C-9 (Δ 2.98 ppm), indicating the presence of a 7β-hydroxyl group. The 13 C NMR spectrum of 5 lacked the C-17 resonance of 1 at δ C 81.25 and had a new carbon atom resonance at δ C 220.70 ppm, suggesting that an oxidation had taken place at C-17.…”

“…NMR data of 5 were comparable to the literature. 6 The fifth metabolite was identified as 7β,17βdihydroxyandrost-4-ene-3-one 6. The 13 C NMR spectrum of 6 had two characteristic resonances at δ C 74.92 and 81.09 ppm, suggesting the presence of 7β-and 17β-hydroxyl groups, respectively.…”

Microbial hydroxylation of steroids. 10. Rearrangement during epoxidation and hydroxylation, and the stepwise nature of these enzymic reactions

“…The former yields only lla-hydroxy progesterone (14d), and we have previously demonstrated that the latter gives rise only to 11-keto progesterone (14c), probably via a halohydrin intermediate (25). One might expect a rate retardation in the metabolism of 14b compared with that of 14a in the event that the reaction proceeded via a radical abstraction process (Scheme 1, route B).…”

One-pot biosynthesis of 7β-hydroxyandrost-4-ene-3,17-dione from phytosterols by cofactor regeneration system in engineered mycolicibacterium neoaurum

“…For the hydroxylation of steroids, biotransformation has been widely accepted as an available way due to the comparatively higher stereo-selectivity [ 12 , 13 ], and some microbial hydroxylation methods, such as 11α - and 11β -hydorxylation, have already been industrially applied for decades [ 14 , 15 ]. Up to now, some filamentous fungi that can hydroxylate steroids at C7β have been screened to allow the production of 7β-OHSt by microbial transformations [ 16 – 18 ]. However, these strains have not been applied in the industry because of the insufficient regio- and stereo-selectivities and low conversion rates.…”