Progesterone side-chain degradation by some species ofAspergillus flavus group

Seventy isolates belonging to 6 species and one variety of A. flavus group were shown to degrade the progesterone side-chain to yield delta 4-androstene-3,17-dione and testosterone. The isolates of five species (A. flavo-furcatis, A. flavus, A. oryzae, A. parasiticus and A. tamarii) possessed enzyme systems catalyzing the opening of ring D and formed testololactone as final steroid metabolite in addition to their ability to produce the above mentioned two products. 11 beta-Hydroxy-delta 4-androstene-3,17-dione was formed by only A. flavus and A. tamarii while 11 beta-hydroxytestosterone was produced by A. flavo-furcatis, A. parasiticus and A. subolivaceus. The chromatographic resolution of the mixture products obtained (when the selective isolate of each species reacted with 1 g of progesterone) revealed that 60-75% of progesterone was converted into delta 4-androstene-3,17-dione (8-30%), testosterone (7-33%), testololactone (14-37%) and other products (3-40%). The most bioconversion activity was exhibited by A. oryzae, followed by A. parasiticus. The highest values of delta 4-androstene-3,17-dione (30% of added progesterone) and testosterone (33%) were formed by A. flavus var. columnaris while those of testololactone (37%) were produced by A. oryzae. A systematic variation could be observed between the different tested species of A. flavus group with respect to the transformation reactions of progesterone. Comparative biotransformation results showed that essential differences exist between the tested species in this group; this biochemical differentiation may supplement the morphological and other physiological criteria used in the identification of the different species in the A. flavus group.     

Fate of novel Quasi reverse steroidal substrates by Aspergillus tamarii KITA: bypass of lactonisation and an exclusive role for the minor hydroxylation pathway

The fungus Aspergillus tamarii transforms progesterone to testololactone in high yield through a flexible four-step enzymatic pathway. To date no studies have investigated the effect of transposition of steroidal functionality between ring-A and ring-D in order to determine the effect on steroidal metabolism. A series of novel quasi reverse steroids (7-9) were synthesised through Linz and Schafer oxidation where 14-en-16-one functionality is generated on ring-D of the steroid. To retain parity with the normal series ring-D functionality was substituted onto ring-A of the analogues. All of the analogues (7-9) were handled through a minor 11beta-hydroxylation pathway with no lactones being formed. In previous studies testololactone is produced within the first 12 h of metabolism. A time course experiment demonstrated that the transformation of these steroids initiated with the formation of a 3beta-hydroxy group after which (48-96 h) hydroxylation through a minor pathway occurred, indicating that this hydroxylase was only then being induced. This is in contrast to the normal fungal metabolism of xenobiotic steroidal substrates where they are primarily hydroxylated. Furthermore, ring-D hydrogenation is reported for the first time as is reverse metabolism on this pathway. All metabolites were isolated by column chromatography and were identified by 1H and 13C NMR spectroscopy, DEPT analysis and other spectroscopic and crystallographic data.     

Hydroxylation of testosterone at carbons 1, 2, 6, 7, 15 and 16 by the hepatic microsomal fraction from adult female C57BL/6J mice.

The metabolism of a mixture of [4-14C]- and [7 beta-2H]testosterone by the hepatic microsomal fraction from adult femal C57BL/6J mice has been investigated. The following metabolites were identified by their mass spectra and by their retention times on gas chromatography on one or two phases: 1epsilon-, 2beta-, 6alpha-, 6beta-, 7alpha-, 15alpha-, 15beta-, 16alpha- and 16beta-hydroxytestosterone; 6alpha-, 6beta- and 7alpha-hydroxy-4-androstene-3,17-dione; and 4-androstene-3,17-dione. A compound tentatively identified as 6- or 7-oxotestosterone was also isolated. 17beta-Hydroxy-4,6-androstadien-3-one, 17beta-hydroxy-1,4-androstadien-3-one and 4,6-androstadiene-3,17-dione were identified but are considered to arise non-enzymatically from 7alpha-hydroxytestosterone, 1epsilon-hydroxytestosterone and 7alpha-hydroxy-4-androstene-3,17-dione, respectively.     

Microbial transformation of 3-hydroxy-5,6-cyclopropanocholestanes--an alternative route to 6-methylsteroids

Incubation of 3beta-hydroxy-5,6alpha-cyclopropano-5alpha-cholestane (4), 3beta-hydroxy-5,6beta-cyclopropano-5beta-cholestane (5), and 3beta-hydroxy-5,6alpha-cyclopropano-5alpha-cholest-7-e ne (6) with Mycobacterium sp. (NRRL B-3805) gave a mixture of side chain cleaved 17-keto steroids as the major products in 52, 57, and 69% yields, respectively. Among these 17-keto steroids, the cyclopropyl ring eliminated product, androst-4-ene-3,17-dione (9), was isolated in 6, 4, and 8% yields, respectively. A cyclopropyl ring migration product, 6alpha,7alpha-cyclopropanoandrost-4-ene-3,17-dione (16), was isolated from the incubation mixture of 6 in 4% yield, also 10% yield of 16 was obtained when 5, 6alpha-cyclopropano-5alpha-androst-7-ene-3,17-dione (12) was incubated. The cyclopropyl ring opening and subsequent reduction followed by oxidation of the two major biotransformation products, 5, 6beta-cyclopropano-5beta-androsta-3,17-dione (10) and 5, 6alpha-cyclopropano-5alpha-androsta-3,17-dione (7), gave 6beta- and 6alpha-methylandrost-4-ene-3,17-dione in 60, and 45% yields, respectively.     

Progesterone transformations by three species ofHumicola

Five isolates belonging to three species of the genusHumicola were tested in this study for their ability to transform progesterone. An oxidative splitting of the side chain of progesterone with the formation of androst-4-ene-3,17-dione, testosterone and testololactone was achieved by all isolates tested ofH. fuscoatra andH. grisea. H. hyalothermophila transformed progesterone to 11α-, 11β-, 17α- and 21-hydroxyprogesterone and a dihydroxyl product (11α, 17α-dihydroxyprogesterone) with the addition of two trihydroxyl products,viz. cortisol and epicortisol. Qualitative and quantitative analysis of the different products obtained when a selective isolate of each species acted on progesterone were conducted. The chromatographic resolution of the mixture products obtained when the selective isolate of each ofH. fuscoatra andH. grisea had acted individually on 1 g progesterone revealed the presence of 25 and 20% unchanged progesterone, 20 and 22% androst-4-ene-3,17-dione, 25 and 23% testosterone and 30 and 35% testololactone, respectively. Seventy-four % of progesterone were bioconverted byH. hyalothermophila into 21-hydroxyprogesterone (6%), 17α-hydroxyprogesterone (5%), 11α-hydroxyprogesterone (11%), 11β-hydroxyprogesterone (12%), 11α,17α-dihydroxyprogesterone (5%), cortisol (21%) and epicortisol (13%). This is the first record of conversion of progesterone to both cortisol and epicortisol byH. hyalothermophila.     

Omega 1-decoupled 1H homonuclear shift-correlated nuclear magnetic resonance spectroscopy (COSYDEC) applied to steroids

Problems of cross-peak overlap in two-dimensional 1H homonuclear shift-correlated (COSY) spectra of steroids can often be avoided by use of the omega 1-decoupled COSY (COSYDEC) method. The selection of experimental parameters is discussed, and COSYDEC spectra are illustrated for 17a-oxa-D-homoandrost-4-ene-3,17-dione (testololactone), testosterone, and 17 alpha-hydroxyprogesterone. In a good case, a COSYDEC spectrum obtained at 250 MHz allows cross-peak recognition and assignment with facility comparable to that available only at 500 MHz for normal COSY spectra.     

Transformation of 4-androsten-3,17-dione by growing cultures and cell extracts of Clostridium paraputrificum.

Growing cultures of Clostridium paraputrificum transformed 4-androsten-3,17-dione to 3 alpha-hydroxy-5 beta-androstan-17-one in a sequential manner with 5 beta-androstan-3,17-dione as an intermediate. The addition of 1.5 mM menadione to log-phase cultures which had formed 5 beta-androstan-3,17-dione resulted in a partial reoxidation of this steroid to 4-androsten-3,17-dione. However, this treatment also resulted in transient inhibition of culture growth. Resumption of growth was accompanied by complete reduction of 4-androsten-3,17-dione to 5 beta-androstan-3,17-dione. Cell extracts of C. paraputrificum were capable of carrying out these reductive transformations in the absence of added cofactors. However, Sephadex G-25 treated extracts required NADH or NADPH for these reactions. A flavin nucleotide, either FAD (plus NADH or NADPH) or FMN (plus NADH) was highly stimulatory for 4-androsten-3,17-dione reduction to 5 beta-androstan-3,17-dione. NADH was the preferred reduced pyridine nucleotide for reduction of the C4-C5 double bond, while time-course measurements suggested that NADPH was the preferred donor for reduction of the 3-keto group.     

Microbial 16β-Hydroxylation of Steroids with Aspergillus niger

Microbial 16β-hydroxylation of some steroids with Wojnowicia graminis, Corticium centrifugum and Bacillus megaterium has been reported, but not 16β-hydroxylation of normal 17-oxo steroids with Aspergillus niger. This time, we tried microbial transformation of dehydroepiandrosterone with this fungus, and obtained 4-androstene-3,17-dione, 17β-hydroxy-4-androstene-3,16-dione, 16β,17β-dihydroxy-4-androsten-3-one and a new compound, 16β-hydroxy-4-androstene-3,17-dione. This new compound was also obtained by the fermentation of 4-androstene-3,17-dione and testosterone.     

Studies on anabolic steroids--4. Identification of new urinary metabolites of methenolone acetate (Primobolan) in human by gas chromatography/mass spectrometry

The metabolism of methenolone acetate (17 beta-acetoxy-1-methyl-5 alpha-androst-1-en-3-one), a synthetic anabolic steroid, has been investigated in man. After oral administration of a 50 mg dose of the steroid to two male volunteers, twelve metabolites were detected in urine either in the glucuronide, sulfate or free steroid fractions. Methenolone, the parent steroid was detected in urine until 90 h after administration. Its cumulative urinary excretion accounted for 1.63% of the ingested dose. With the exception of 3 alpha-hydroxy-1-methylen-5 alpha-androstan-17-one, the major biotransformation product of methonolone acetate, metabolites were excreted in urine at lower levels, through minor metabolic routes. Most of methenolone acetate metabolites were isolated from the glucuronic acid fraction, namely methenolone, 3 alpha-hydroxy-1-methylen-5 alpha-androstan-17-one, 3 alpha-hydroxy-1 alpha-methyl-5 alpha-androstan-17-one, 17-epimethenolone, 3 alpha,6 beta-dihydroxy-1-methylen-5 alpha-androstan-17-one, 2 xi-hydroxy-1-methylen-5 alpha-androstan-3,17-dione, 6 beta-hydroxy-1-methyl-5 alpha-androst-1-en-3,17-dione, 16 alpha-hydroxy-1-methyl-5 alpha-androst-1-en-3,17-dione and 3 alpha,16 alpha-dihydroxy-1-methyl-5 alpha-androst-1-en-17-one. Interestingly, the metabolites detected in the sulfate fraction were isomeric steroids bearing a 16 alpha- or a 16 beta-hydroxyl group, whereas 1-methyl-5 alpha-androst-1-en-3,17-dione was the sole metabolite isolated from the free steroid fraction. Steroids identity was assigned on the basis of the mass spectral features of their TMS ether, TMS enol-TMS ether, MO-TMS, and d9-TMS ether derivatives and by comparison with reference and structurally related steroids. The data indicated that methenolone acetate was metabolized into several compounds resulting from oxidation of the 17-hydroxyl group and reduction of A-ring substituents, with or without concomitant hydroxylation at the C6 and C16 positions.     

Distinct metabolic handling of 3beta-hydroxy-17a-oxa-D-homo-5alpha-androstan-17-one by the filamentous fungus Aspergillus tamarii KITA: Evidence in support of steroid/hydroxylase binding hypothesis

Aspergillus tamarii KITA transforms progesterone in to testololactone in high yield through a sequential four-step enzymatic pathway which also has the flexibility to transform a range of steroidal substrates. This study has investigated the further metabolism of testololactone and a range of fully saturated steroidal lactone analogues. In contrast to testololactone, which even after 120 h incubation did not undergo further metabolism, the lactone analogues entered the minor hydroxylation pathway. Uniquely, after forming 3beta-hydroxy-17a-oxa-D-homo-5alpha-androstan-17-one (48 h) 4 distinct positions on the steroid skeleton were monohydroxylated (11beta, 6beta, 7beta, 11alpha) which geometrically relate to the four binding positions (normal, reverse, inverted normal and inverted reverse) possible within the steroidal hydroxylase(s). This is the first evidence demonstrating the four possible steroid/hydroxylase(s) binding interactions with a single molecule that has previously been hypothesized with a single organism. In addition a rare 1beta-monohydroxylation was observed, this may be indicative of dehydration generating 1-ene functionality in A. tamarii rather than dehydrogenation as reported in man and microorganisms. The importance of these findings in relation to steroid/hydroxylase binding interactions is discussed.     

Biotransformation of 3b-Hydroxyandrost-5-en-17-one by Cell Suspension Cultures of Catharanthus roseus

Catharanthus roseus (L.) G. Don cell suspension cultures were used to transform 3b-hydroxyandrost-5-en-17-one, the products were isolated by chromatographic methods. Their structures were established by means of NMR and MS spectral analyses. Nine metabolites were respectively elucidated as: androst-4-ene-3,17-dione (Ⅰ), 6a-hydroxyandrost-4-ene-3,17-dione (Ⅱ), 6a,17b-dihydroxyandrost-4-en-3-one (Ⅲ), 6b-hydroxyandrost-4-ene-3,17-dione (Ⅳ), 17b-hydroxyandrost-4-en-3-one (Ⅴ), 15a,17b-dihydroxyandrost-4-en-3-one (Ⅵ), 15b,17b-dihydroxyandrost-4-en-3-one (Ⅶ), 14a-hydroxyandrost-4-ene-3,17-dione (Ⅷ), 17b-hydroxyandrost-4-ene-3,16-dione (Ⅸ). It is the first time to obtain the above compounds by biotransformation with Catharanthus roseus cell cultures.     

Microbial oxidation of dehydroepiandrosterone and related compounds.

The oxidation of dehydroepiandrosterone (DHEA), 4-androstene-3, 17-dione, and estrone with Streptomyces roseochromogenes NRRL B-1233 was studied. The oxidation products were isolated and identified as as 16alpha-hydroxy-DHEA, 16alpha-hydroxy-4-androstene-3,17-dione and 16alpha-hydroxyestrone. The yields of these three products were 85%, 41% and 18%, respectively. This indicates the substrate stereospecificity of 16alpha-hydroxylase of the organism. An interrelationship between cell growth and the formation of 16alpha-hydroxylated steroid was observed in any case. For formation of 16alpha-hydroxy-DHEA, 16alpha-hydroxylase showed good activity at DHEA concentration of 3.47 x 10(-4)M. In the case of DHEA, 16alpha-hydroxy-4-androstene-3,17-dione and 5-androstene-3beta, 16alpha, 17beta-triol were obtained after the yield of 16alpha-hydroxy-DHEA reached the maximum yield for about 30 hr. The oxidation pathway of DHEA is discussed.     

The degradation of cholic acid by Pseudomonas sp. N.C.I.B. 10590 under anaerobic conditions.

The bacterial degradation of cholic acid under anaerobic conditions by Pseudomonas sp. N.C.I.B. 10590 was studied. The major unsaturated neutral compound was identified as 12 beta-hydroxyandrosta-4,6-diene-3,17-dione, and the major unsaturated acidic metabolite was identified as 12 alpha-hydroxy-3-oxochola-4,6-dien-24-oic acid. Eight minor unsaturated metabolites were isolated and evidence is given for the following structures: 12 alpha-hydroxyandrosta-4,6-diene-3,17-dione, 12 beta,17 beta-dihydroxyandrosta-4,6-dien-3-one, 12 beta-hydroxyandrosta-1,4,6-triene-3,17-dione, 12 beta,17 beta-dihydroxyandrosta-1,4,6-trien-3-one, 12 beta-hydroxyandrosta-1,4,6-triene-3,17-dione, 12 beta,17 beta-dihydroxyandrosta-1,4,6-trien-3-one, 12 alpha-hydroxyandrosta-1,4-diene-3,17-dione, 3-hydroxy-9,10-secoandrosta-1,3,5(10)-triene-9,17-dione, 3,12-dioxochola-4,6-dien-24-oic acid and 12 alpha-hydroxy-3-oxopregna-4,6-diene-20-carboxylic acid. In addition, a major saturated neutral compound was isolated and identified as 3 beta,12 beta-dihydroxy-5 beta-androstan-17-one, and the only saturated acidic metabolite was 7 alpha,12 alpha-dihydroxy-3-oxo-5 beta-cholan-24-oic acid. Nine minor saturated neutral compounds were also isolated, and evidence is presented for the following structures: 12 beta-hydroxy-5 beta-androstane-3,17-dione, 12 alpha-hydroxy-5 beta-androstane-3,17-dione, 3 beta,12 alpha-dihydroxy-5 beta-androstan-17-one, 3 alpha,12 beta-androstan-17-one, 3 alpha,12 alpha-dihydroxy-5 beta-androstan-17-one, 5 beta-androstane-3 beta,12 beta,17 beta-triol, 5 beta-androstane-3 beta,12 alpha,17 beta-triol, 5 beta-androstane-3 alpha,12 beta,17 beta-triol and 5 beta-androstane-3 alpha,12 alpha,17 beta-triol. The induction of 7 alpha-dehydroxylase and 12 alpha-dehydroxylase enzymes is discussed, together with the significance of dehydrogenation and ring fission under anaerobic conditions.     

Microbial transformation of androst-4-ene-3,17-dione by Beauveria bassiana

The microbial transformation of androst-4-ene-3,17-dione (I) by the fungus Beauveria bassiana CCTCC AF206001 has been investigated using pH 6.0 and 7.0 media. Two hydroxylated metabolites were obtained with the pH 6.0 medium. The major product was 11alpha-hydroxyandrost-4-ene-3,17-dione (II) whereas the minor product was 6beta,11alpha-dihydroxyandrost-4-ene-3,17-dione (III). On the other hand, four hydroxylated and/or reduced metabolites were obtained with the pH 7.0 medium. The major product was 11alpha,17beta-dihydroxyandrost-ene-3-one (V) and the minor products were 17beta-hydroxyandrost-ene-3-one (IV), 6beta,11alpha,17beta-trihydroxyandrost-ene-3-one (VI) and 3alpha,11alpha,17beta-trihydroxy-5alpha-androstane (VII). The products were purified by chromatographic methods, and were identified on the basis of spectroscopic methods. This fungus strain is clearly an efficient biocatalyst for 11alpha-hydroxylation and reduction of the 17-carbonyl group.     

Biotransformation of dehydroepiandrosterone (DHEA) with Penicillium griseopurpureum Smith and Penicillium glabrum (Wehmer) Westling

Microbial transformation of dehydroepiandrosterone (DHEA, 1) using Penicillium griseopurpureum Smith and Penicillium glabrum (Wehmer) Westling has been investigated. Neither fungi had been examined previously for steroid biotransformation. One novel metabolic product of DHEA (1) transformed with P. griseopurpureum Smith, 15α-hydroxy-17a-oxa-d-homo-androst-4-ene-3,17-dione (5), was reported for the first time. The steroid products were assigned by interpretation of their spectral data such as ¹H NMR, ¹³C NMR, IR, and HR-MS spectroscopy. P. griseopurpureum Smith was proven to be remarkably efficient in oxidation of the DHEA (1) into androst-4-en-3,17-dione (2). The strain was also observed to yield different monooxygenases to introduce hydroxyl groups at C-7α, -14α, and -15α positions of steroids. Preference for Baeyer–Villiger oxidation to lactonize D ring and oxidation of the 3β-alcohol to the 3-ketone were observed in both incubations. The strain of P. glabrum (Wehmer) Westling catalyzed the steroid 1 to generate both testololactone 3, and d-lactone product with 3β-hydroxy-5-en moiety 8. In addition, the strain promoted hydrogenation of the C-5 and C-6 positions, leading to the formation of 3β-hydroxy-17a-oxa-d-homo-5α-androstan-3,17-dione (9).The biotransformation pathways of DHEA (1) with P. glabrum (Wehmer) Westling and P. griseopurpureum Smith have been investigated, respectively. Possible metabolic pathways of DHEA (1) were proposed.     

Ring-B functionalized androst-4-en-3-ones and ring-C substituted pregn-4-en-3-ones undergo differential transformation in Aspergillus tamarii KITA: ring-A transformation with all C-6 substituted steroids and ring-D transformation with C-11 substituents

The fungus Aspergillus tamarii transforms progesterone 1 into testololactone 5 in high yield through a four-step enzymatic pathway which is flexible to a range of steroidal substrates. To date, no studies have investigated the fate of C-6 (ring-B) and C-11 (ring-C) functionalized steroidal substrates on metabolism. Remarkably all of the C-6 functionalized substrates underwent reductive metabolism on ring-A in contrast to C-11 functionalized steroids where only ring-D oxidative or reductive transformation occurred. In order to discern the precise role of the functional groups in directing metabolism 6-ketoprogesterone 10 with functionality at C-6 and the ring-D methyl ketone underwent reductive and oxidative transformation on both terminal A and D rings showing that this functionality was directing metabolism. Androst-4-en-3,6-dione 12 devoid of ring-D functionality underwent reductive metabolism on ring-A proving that the C-6 functionality was directing metabolism to this ring with the ring-D methyl ketone responsible for generating transformation at this position. Functionality at C-11 exclusively controlled entry into and degree of metabolism on the lactonization pathway. These novel findings may have important bearing in the future understanding of structure activity relationships in revealing new metabolic pathways and further affords a unique opportunity for generation of novel bioactive steroidal compounds.     

The facile bioconversion of testosterone by alginate-immobilised filamentous fungi

The potential for biotransformation of the substrate 17β-hydroxyandrost-4-en-3-one (testosterone) by six filamentous fungi, namely, Rhizopus oryzae ATCC 11145, Mucor plumbeus ATCC 4740, Cunninghamella echinulata var. elegans ATCC 8688a, Aspergillus niger ATCC 9142, Phanerochaete chrysosporium ATCC 24725 and Whetzelinia sclerotiorum ATCC 18687, was investigated. In this study both free cells and macerated mycelia immobilised in calcium alginate were utilised and the results (products, % yields, % transformation) were compared. In general the encapsulated cells of the microorganisms effectively generated products similar to those found using free cells. However, with immobilised macerated mycelia, isolation of the transformation products was expedited by the simple work up procedure, and their purification was facilitated by the absence of fungal secondary metabolites. Twenty seven analogues of testosterone were generated, wherein the androstane skeleton was functionalised at C-1β, -2β, -6β, -7α, -11α, -14, -15α, -15β and -16β by the moulds. Redox chemistry was also observed. Seven of the analogues, 6β,11α,17β-trihydroxyandrost-4-en-3-one, 6β,14α,17β-trihydroxyandrost-4-en-3-one, 2,6β-dihydroxyandrosta-1,4-diene-3,17-dione, 2β,16β-dihydroxyandrost-4-ene-3,17-dione, 2β,6β-dihydroxyandrost-4-ene-3,17-dione, 2β,15β,17β-trihydroxyandrost-4-en-3-one and 2β,3α,17β-trihydroxyandrost-4-ene, were novel compounds. Five others, namely, 7α,17β-dihydroxyandrost-4-en-3-one, 6β,14α-dihydroxyandrost-4-ene-3,17-dione, 15α,17β-dihydroxyandrost-4-en-3-one, 16β,17α-dihydroxyandrost-4-en-3-one and 2β,16β,17β-trihydroxyandrost-4-en-3-one, were fully characterised for the first time.     

Biotransformation of dehydroepiandrosterone with Macrophomina phaseolina and β-glucuronidase inhibitory activity of transformed products

The biotransformation of dehydroepiandrosterone (1) with Macrophomina phaseolina was investigated. A total of eight metabolites were obtained which were characterized as androstane-3,17-dione (2), androst-4-ene-3,17-dione (3), androst-4-ene-17β-ol-3-one (4), androst-4,6-diene-17β-ol-3-one (5), androst-5-ene-3β,17β-diol (6), androst-4-ene-3β-ol-6,17-dione (7), androst-4-ene-3β,7β,17β-triol (8), and androst-5-ene-3β,7α,17β-triol (9). All the transformed products were screened for enzyme inhibition, among which four were found to inhibit the β-glucuronidase enzyme, while none inhibited the α-chymotrypsin enzyme.     

Microbiological hydroxylation of androst-1,4-dien-3,17-dione by Neurospora crassa

Nine hydroxy-derived androstadiene compounds were isolated from the fermentation broth of Neurospora crassa when incubated in the presence of androst-1,4-dien-3,17-dione (ADD; I) for 7 days. Hydroxylations at 6β, 7β, 11α, 14α- positions and 17-carbonyl reduction of the substrate were the characteristics observed in this biotransformation. Their structures were determined by spectroscopic methods as 17β-hydroxyandrost-1,4-dien-3-one (II), 14α-hydroxyandrost-1,4-dien-3,17-dione (III), 6β-hydroxyandrost-1,4-dien-3,17-dione (IV), 11α-hydroxyandrost-1,4-dien-3,17-dione (V), 6β,17β-dihydroxyandrost-1,4-dien-3-one (VI), 7β-hydroxyandrost-1,4-dien-3,17-dione (VII), 14α,17β-dihydroxyandrost-1,4-dien-3-one (VIII), 6β,14α-dihydroxyandrost-1,4-dien-3,17-dione (IX), and 11α,17β-dihydroxyandrost-1,4-dien-3-one (X). A new steroid substance, 6β,14α-dihydroxyandrost-1,4-dien-3,17-dione (IX), was also characterized during this study. The best fermentation condition was found to be 7-day incubation at 25°C and pH values of 5.0–6.0 in the presence of 0.05 g 100 mL^?1 of the substrate. At a concentration above 0.075 g 100 mL^?1, the biotransformation was completely inhibited.     

Microbial introduction of a 16 alpha-hydroxyl function into the steroid nucleus.

The introduction of a 16 alpha-hydroxyl function into the steroid nucleus was studied in resting cells of Streptomyces roseochromogenes NRRL B-1233. The oxidation product of dehydroepiandrosterone (DHEA) was identified as 16 alpha-hydroxy DHEA by using thin-layer and gas-liquid chromatography. A linear relation between cell concentration and 16 alpha-OH-DHEA formation was observed. 16 alpha-Hydroxylase showed good activity at pH 8.0 for 16 alpha-OH-DHEA formation. The enzyme showed good activity at 3.1 x 10(-4) M DHEA. The oxidation products of pregnenolone, 4-androstene-3,17-dione, estrone, and 5-androstene-3 beta,17 beta-diol as well as of other substrates were identified as the 16 alpha-hydroxy steroid, respectively. The rates of microbial 16 alpha-hydroxylation were as follows: 76.9% for DHEA, 50.4% for pregnenolone, 43.9% for 4-androstene-3,17-dione, 34.3% for estrone, and 19.6% for 5-androstene-3 beta,17 beta-diol. The organism tested catalyzes 16 alpha-hydroxylation of a wide variety of steroids.