- Microbial transformation of dehydroepiandrosterone (DHEA) by some fungi
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In this work, biotransformations of dehydroepiandrosterone (DHEA) 1 by Ulocladium chartarum MRC 72584, Cladosporium sphaerospermum MRC 70266 and Cladosporium cladosporioides MRC 70282 have been reported. U. chartarum MRC 72584 mainly hydroxylated 1 at C-7α and C-7β, accompanied by a minor hydroxylation at C-4β, a minor epoxidation from the β-face and a minor oxidation at C-7 subsequent to its hydroxylations. 3β,7β-Dihydroxy-5β,6β-epoxyandrostan-17-one 6, 3β,4β,7α-trihydroxyandrost-5-en-17-one 7 and 3β,4β,7β-trihydroxyandrost-5-en-17-one 8 from this incubation were identified as new metabolites. C. sphaerospermum MRC 70266 converted some of 1 into a 3-keto-4-ene steroid and then hydroxylated at C-6α, C-6β and C-7α, accompanied a minor 5α-reduction and a minor oxidation at C-6 following its hydroxylations. C. sphaerospermum MRC 70266 also hydroxylated some of 1 at C-7α and C-7β. C. cladosporioides MRC 70282 converted almost half of 1 into a 3-keto-4-ene steroid and then hydroxylated at C-6α and C-6β. C. cladosporioides MRC 70282 also reduced some of 1 at C-17.
- Yildirim, Kudret,Kuru, Ali,Y?lmazer Keskin, Semra,Ergin, Sinan
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p. 465 - 474
(2020/11/12)
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- Microbial transformation of androstenedione by Cladosporium sphaerospermum and Ulocladium chartarum
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In this work, incubations of androstenedione 1 with Cladosporium sphaerospermum MRC 70266 and Ulocladium chartarum MRC 72584 have been reported. C. sphaerospermum MRC 70266 mainly hydroxylated 1 at C-6β, accompanied by a hydroxylation at C-15α, a reduction at C-17, a 5α-reduction and oxidations at C-6 and C-16 following hydroxylations. U. chartarum MRC 72584 hydroxylated 1 at C-6β, C-7α, C-7β and C-14α, accompanied by an oxidation at C-6 following its hydroxylation, a reduction at C-17 and a 5α-reduction. 6β,17β-Dihydroxyandrost-4-en-3,16-dione 8, one of the metabolites from the incubation of 1 with C. sphaerospermum MRC 70266, was determined as a new compound.
- Yildirim, Kudret,Kuru, Ali,Kü?ükba?ol, Eda
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- Microbial transformation of androst-4-ene-3,17-dione by three fungal species Absidia griseolla var. igachii, Circinella muscae and Trichoderma virens
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Microbial transformation of androst-4-ene-3,17-dione (AD;I) by three fungal species including Absidia griseolla var. igachii, Circinella muscae and Trichoderma virens was investigated for the first time. While A. griseolla and C. muscae carried out hydroxylation reactions, the third fungi performed reduction of the 17-carbonyl group in a chemoselective manner. Incubation of AD by A. griseolla yielded four metabolites 6β- (II), 7α- (III), 7β- (VI) and 14α-hydroxy-AD (V), among which 6β-hydroxy-AD (II) was identified as the major product. Furthermore, the metabolites produced during AD biotransformation by C. muscae were 6β- (II), 7β- (III) and 14α-hydroxy-AD (V). On the other hand, T. virens remarkably reduced AD into testosterone (VI) as the only product with 60% yield. These metabolites were purified by TLC and identified by 1H NMR, 13C NMR and other spectroscopic data.
- Heidary, Marjan,Habibi, Zohreh
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- The generation of a steroid library using filamentous fungi immobilized in calcium alginate Dedicated to the memory of Professor Sir John W. Cornforth, University of Sussex (1917-2013).
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Four fungi, namely, Rhizopus oryzae ATCC 11145, Mucor plumbeus ATCC 4740, Cunninghamella echinulata var. elegans ATCC 8688a, and Whetzelinia sclerotiorum ATCC 18687, were subjected to entrapment in calcium alginate, and the beads derived were used in the biotransformation of the steroids 3β,17β-dihydroxyandrost-5-ene (1) and 17β-hydroxyandrost-4-en-3-one (2). Incubations performed utilized beads from two different encapsulated fungi to explore their potential for the production of metabolites other than those derived from the individual fungi. The investigation showed that steroids from both single and crossover transformations were typically produced, some of which were hitherto unreported. The results indicated that this general technique can be exploited for the production of small libraries of compounds.
- Peart, Patrice C.,Reynolds, William F.,Reese, Paul B.
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- Novel metabolites of dehydroepiandrosterone and progesterone obtained in Didymosphearia igniaria KCH 6670 culture
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Dehydroepiandrosterone (DHEA) (10) and its five derivatives: testosterone (1), androstenedione (2), 17α-methyltestosterone (6), progesterone (13) and pregnenolone (14) were subjected to microbial transformation by the filamentous fungus Didymosphaeria igniaria KCH 6670. The predominant metabolism of the incubated 5-ene steroids (10 and 14) occurred through 3β-hydroxy-steroid dehydrogenase/5,4-en isomerase pathways resulting in the generation of a 4-en-3-oxo system on ring-A. The transformations of C 19 steroids (1, 2, and 10) included a hydroxylation at 7α position, ketone-alcohol interconversion at C-17 and reduction of the double bond at C-4 and 3-keto group to the 3β-alcohol with 5α- stereochemistry at A/B ring. D. igniaria also carried out 6(7)-dehydrogenation and 6,7β-epoxidation during transformation of DHEA. Under these conditions transformation of DHEA (10) gave four products: 7α-hydroxyandrost-4-en-3, 17-dione (4), 17β-hydroxyandrost-4,6-dien-3-one (11), 17β- hydroxyandrost-6β-epoxy-4-en-3-one (12) and 3β,17β-dihydroxy- 5α-androstane (5). The compounds 11 and 12 are identified as DHEA metabolites for the first time. The transformation of C21 steroids (13 and 14) led to the mixture of mono- (mainly 11α- and 15β-) and dihydroxy- (7α,15β-; 14α,15β-; 11α,15β-; 11α,14α-) products. 7α,15β-Dihydroxypregnan-4-en-3,20- dione (18) and 14α,15β-dihydroxypregnan-4-en-3,20-dione (19) were found to be new compounds. The main product of transformation of 17α-methyltestosterone (6) was 12β-hydroxy-17α- methyltestosterone (7). The results of these transformations demonstrate the dependence of hydroxylation position on the structure of steroid nucleus.
- Janeczko, Tomasz,Swizdor, Alina,Dmochowska-Gladysz, Jadwiga,Bialonska, Agata,Ciunik, Zbigniew,Kostrzewa-Suslow, Edyta
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experimental part
p. 24 - 31
(2012/10/08)
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- Microbial transformation of steroids: Contribution to 14α-hydroxylations
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The regioselective and stereoselective hydroxylation of steroids by fungal strains previously known for their hydroxylation capabilities, such as Thamnostylum (= Helicostylum) piriforme ATCC 8992, Mucor griseocyanus ATCC 1207a, Actinomucor elegans (= Mucor parasiticus) MMP 3122 (Mucorales), and Zygodesmus sp. ATCC 14716, was investigated with special interest for the 14α-hydroxylation reaction. A preliminary screening had shown that some of these microorganisms were adequate for the production of 14α-hydroxylated derivatives of the following steroids: progesterone, 5β-pregnane-3,20- dione, 3β-hydroxy-5β-pregnane-20-one, 3β-hydroxy-5β-17(αH)-etianic acid methyl ester, androst-4-ene-3,17-dione, and testosterone. About 20 metabolites have been isolated and purified by silicagel chromatography and semi-preparative reverse-phase HPLC. These metabolites have been fully characterized by 1H, 13C NMR and mass spectrometry. All the identified metabolites were hydroxylated at some distinct positions, such as 6β-, 7α- , 9α-, 14α-, 15β-, or dihydroxylated at 6β, 14α-, 7α, 14α-, 9α, 14α- , 14α, 15α-, 14α, 15β-positions; nine of these metabolites have not been reported previously. The relationship between the structural features of the investigated steroids and the site-specific hydroxylation has been delineated, and progesterone was found to be the best substrate for the production of 14α-hydroxylated derivative, using T. piriforme.
- Azerad, Robert
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p. 337 - 352
(2007/10/02)
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- Kinetic study of HCG induced decrease of microsomal 7α-hydroxylase activity in rat testes
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Microsomes from rat testes were incubated with varying concentrations of 14C labelled testosterone and androstenedione. The production of 7α-hydroxytestosterone and 7α-hydroxyandrostenedione was followed; K(m) and V(m) values were calculated from Lineweaver-Burk curves. A sustained treatment of rats with HCG resulted in a considerable decrease of the maximal 7α-hydroxylation rate (V(m)) whereas the K(m) value was not changed. V(m) of microsomes from normal rats, when incubated with microsomes from HCG-treated animals, was also decreased substantially. It is concluded that HCG-induced depression of 7α-hydroxylation capacity of testicular microsomes is at least in part due to non-competitive inhibition of the enzyme.
- Eechaute,Lacroix,Leusen
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p. 647 - 660
(2007/10/02)
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