Biotransformation XLVII: transformations of 5-ene steroids in Fusarium culmorum culture.

The course of the transformation of six 5-ene steroids with varying substituents at C-17 or/and C-3: dehydroepiandrosterone (DHEA), 5-androsten-3beta,17beta-diol, 17alpha-methyl-5-androsten-3beta,17beta-diol, 5-androsten-17-one, 5-androsten-3beta-ol and pregnenolone by Fusarium culmorum was investigated. Three substrates with oxygen functions at C-3 and C-17 i.e. DHEA, 5-androsten-3beta,17beta-diol and 17alpha-methyl-5-androsten-3beta,17beta-diol were hydroxylated entirely at 7alpha-axial, allylic position. The mixture of 7alpha-hydroxy- and 7alpha,15alpha-dihydroxyderivatives was formed during the transformation of pregnenolone and 5-androsten-17-one, from the latter 2alpha,7alpha-dihydroxyderivative was also obtained. 7alpha,15alpha- Dihydroxyderivative was the only product isolated from the 5-androsten-3beta-ol post-transformation mixture. The time-course of the DHEA transformation by F. culmorum shows that the substrate induces 7alpha-hydroxylase activity. DHEA was transformed by androstenedione induced F. culmorum cultures to a larger extent than by a noninduced microorganism; the selectivity of the transformation remained unchanged.

Biotransformation XLV. Transformations of 4-ene-3-oxo steroids in Fusarium culmorum culture.

The course of transformations of five 4-ene-3-oxo steroids with varying substituents at C-17 i.e.: 4-androsten-3-one, androstenedione, testosterone, progesterone and 17alpha-hydroxyprogesterone in Fusarium culmorum culture was investigated. All the substrates were hydroxylated either at 12beta and 15alpha, or at 15alpha or 6beta positions, depending on the structure of the substrate. The main product of 4-androsten-3-one transformation was 12beta,15alpha-diol. A similar 12beta,15alpha-diol was obtained from progesterone, but the main product of transformation of this substrate was 15alpha-hydroxyprogesterone. The products of hydroxylation at 6beta or 15alpha positions were isolated from 17alpha-hydroxyprogesterone. The androstenedione and testosterone transformation mixtures contained the same products (6beta-hydroxyandrostenedione, 6beta-hydroxytestosterone, 15alpha-hydroxyandrostenedione and 15alpha-hydroxytestosterone), but the quantities of 6beta- and 15alpha-alcohols varied, depending on the substrate used. During transformations of these two substrates, apart from hydroxylation, ketone-alcohol interconversion at C-17 occurred.

Biotransformation XXXIX. Metabolism of testosterone, androstenedione, progesterone and testosterone derivatives in Absidia coerulea culture.

The strain of Absidia coerulea was used to investigate the transformations of testosterone, androstenedione, progesterone and testosterone derivatives with additional Cl-C2 double bond and/or 17alpha-methyl group. All the examined substrates were transformed, mainly hydroxylated. It was found that the position and stereochemistry of the introduced hydroxyl group, as well as the yield of products, depended on the structure of the substrate. The first three substrates (hormones) underwent hydroxylation at C-14, and additional hydroxylation at 7alpha was observed in progesterone. The presence of the double bond (C1-C2) in 1-dehydrotestosterone did not influence the position of hydroxylation, but the product with additional C14-C15 double bond (at the same site as hydroxylation) was formed. 17alpha-Methyltestosterone was hydroxylated at the 7alpha position, and also the dehydrogenated product (at the same site, with C6-C7 double bond) was obtained. The testosterone derivative with both C1-C2 double bond and 17alpha-methyl group underwent hydroxylation at the 7alpha or 11beta position, and a little amount of 14alpha, 15alpha epoxide was formed.

Biotransformation--XXXIV. Metabolism of testosterone esters in fungi cultures.

Seven esters of testosterone: acetate, propionate, enanthate, caprate, undecanoate, isobutyrate and isocaproate (some of them are used as drugs) were transformed by microorganisms: Absidia coerulea, Acremonium roseum, Aphanocladium album and Rhodotorula mucilaginosa to obtain some information about their metabolism. It was observed that the presence and structure of the acyl group mainly influenced the degree of transformation. The first step of the reaction was probably hydrolysis of ester, followed by testosterone transformation. Only the branched chain esters were transformed by R. mucilaginosa without hydrolysis of the ester bond.

Reduction of testosterone, androstendione and their derivatives by Aphanocladium album.

A strain of Aphanocladium album reduces the C-3 carbonyl group in testosterone or androstendione to to 3 alpha-allyl alcohol. In some derivatives of these steroids the same carbonyl group is reduced to allyl alcohol with stereospecificity, depending on whether chlorine at C-4 or a 17 alpha-methyl group is present. On the other hand, the presence of C-4 methyl group, a C-19 hydroxy group, a C-17 acetyl one, or a double bond conjugated with the 4-en-3- ketone system totally inhibits the formation of allyl alcohols at C-3. At the same time, the C-17 carbonyl group in androstendione or in its derivatives is reduced to a respective 17 beta-alcohol. In the derivatives with an additional 2-exomethylene group the double bond at this group is reduced.