- One-Step Chemo-, Regio- and Stereoselective Reduction of Ketosteroids to Hydroxysteroids over Zr-Containing MOF-808 Metal-Organic Frameworks
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Zr-containing MOF-808 is a very promising heterogeneous catalyst for the selective reduction of ketosteroids to the corresponding hydroxysteroids through a Meerwein-Ponndorf-Verley (MPV) reaction. Interestingly, the process leads to the diastereoselective synthesis of elusive 17α-hydroxy derivatives in one step, whereas most chemical and biological transformations produce the 17β-OH compounds, or they require several additional steps to convert 17β-OH into 17α-OH by inverting the configuration of the 17 center. Moreover, MOF-808 is found to be stable and reusable; it is also chemoselective (only keto groups are reduced, even in the presence of other reducible groups such as C=C bonds) and regioselective (in 3,17-diketosteroids only the keto group in position 17 is reduced, while the 3-keto group remains almost intact). The kinetic rate constant and thermodynamic parameters of estrone reduction to estradiol have been obtained by a detailed temperature-dependent kinetic analysis. The results evidence a major contribution of the entropic term, thus suggesting that the diastereoselectivity of the process is controlled by the confinement of the reaction inside the MOF cavities, where the Zr4+ active sites are located.
- Llabrés i Xamena, F. X.,Mautschke, H.-H.
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p. 10766 - 10775
(2021/06/15)
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- Formation of 5α-dihydrotestosterone from 5α-androstane-3α,17β-diol in prostate cancer LAPC-4 cells – Identifying inhibitors of non-classical pathways producing the most potent androgen
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5α-Dihydrotestosterone (5α-DHT) possesses a great affinity for the androgen receptor (AR), and its binding to AR promotes the proliferation of prostate cancer (PC) cells in androgen-dependent PC. Primarily synthesized from testosterone (T) in testis, 5α-DHT could also be produced from 5α-androstane-3α,17β-diol (3α-diol), an almost inactive androgen, following non-classical pathways. We reported the chemical synthesis of non-commercially available [4-14C]-3α-diol from [4-14C]-T, and the development of a biological assay to identify inhibitors of the 5α-DHT formation from radiolabeled 3α-diol in LAPC-4 cell PC model. We measured the inhibitory potency of 5α-androstane derivatives against the formation of 5α-DHT, and inhibition curves were obtained for the most potent compounds (IC50 = 1.2–14.1 μM). The most potent inhibitor 25 (IC50 = 1.2 μM) possesses a 4-(4-CF3-3-CH3O-benzyl)piperazinyl methyl side chain at C3β and 17β-OH/17α-C[tbnd]CH functionalities at C17 of a 5α-androstane core.
- Boutin, Sophie,Roy, Jenny,Maltais, René,Poirier, Donald
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supporting information
(2019/11/26)
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- Role of human 3α-hydroxysteroid dehydrogenase isoforms (AKR1C1-AKR1C3) in the extrahepatic metabolism of the steroidal aromatase inactivator Formestane
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The clinical use of the steroidal aromatase inhibitor Formestane (4-hydroxandrostenedione, 4-OHA) in the treatment of advanced ER+ breast cancer has been discontinued, and therefore, interest in this remarkable drug has vanished. As a C-19 sterol, 4-OHA can undergo extensive intracellular metabolism depending on the expression of specific enzymes in the corresponding cells. We used the metabolites 4β-hydroxyandrosterone, 4β-hydroxyepiandrosterone and its 17β-reduced derivative as standards for the proof of catalytic activity present in the cell culture medium and expressed by the isolated enzymes. All of the aldo-keto reductases AKR1C1, AKR1C2, AKR1C3 and AKR1C4 catalysed the reduction of the 3-keto-group and the Δ4,5 double bond of 4-OHA at the same time. Molecular docking experiments using microscale thermophoresis and the examination of the kinetic behaviour of the isolated enzymes with the substrate 4-OHA proved that AKR1C3 had the highest affinity for the substrate, whereas AKR1C1 was the most efficient enzyme. Both enzymes (AKR1C1and AKR1C3) are highly expressed in adipose tissue and lungs, exhibiting 3β-HSD activity. The possibility that 4-OHA generates biologically active derivatives such as the androgen 4-hydroxytestosterone or some 17β-hydroxy derivatives of the 5α-reduced metabolites may reawaken interest in Formestane, provided that a suitable method of administration can be developed, avoiding oral or intramuscular depot-injection administration.
- Wan, Runlan,Kong, Xi,Yang, Youzhe,Tao, Siwen,Chen, Youyou,Teichmann, Alexander Tobias,Wieland, Frank Heinrich
-
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- A Redox Strategy for Light-Driven, Out-of-Equilibrium Isomerizations and Application to Catalytic C-C Bond Cleavage Reactions
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We report a general protocol for the light-driven isomerization of cyclic aliphatic alcohols to linear carbonyl compounds. These reactions proceed via proton-coupled electron-transfer activation of alcohol O-H bonds followed by subsequent C-C β-scission of the resulting alkoxy radical intermediates. In many cases, these redox-neutral isomerizations proceed in opposition to a significant energetic gradient, yielding products that are less thermodynamically stable than the starting materials. A mechanism is presented to rationalize this out-of-equilibrium behavior that may serve as a model for the design of other contrathermodynamic transformations driven by excited-state redox events.
- Ota, Eisuke,Wang, Huaiju,Frye, Nils Lennart,Knowles, Robert R.
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supporting information
p. 1457 - 1462
(2019/01/25)
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- Synthesis of steroid bisglucuronide and sulfate glucuronide reference materials: Unearthing neglected treasures of steroid metabolism
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Doubly or bisconjugated steroid metabolites have long been known as minor components of the steroid profile that have traditionally been studied by laborious and indirect fractionation, hydrolysis and gas chromatography-mass spectrometry (GC–MS) analysis. Recently, the synthesis and characterisation of steroid bis(sulfate) (aka disulfate or bis-sulfate) reference materials enabled the liquid chromatography-tandem mass spectrometry (LC–MS/MS) study of this metabolite class and the development of a constant ion loss (CIL) scan method for the direct and untargeted detection of steroid bis(sulfate) metabolites. Methods for the direct LC–MS/MS detection of other bisconjugated steroids, such as steroid bisglucuronide and mixed steroid sulfate glucuronide metabolites, have great potential to reveal a more complete picture of the steroid profile. However, access to steroid bisglucuronide or sulfate glucuronide reference materials necessary for LC–MS/MS method development, metabolite identification or quantification is severely limited. In this work, ten steroid bisglucuronide and ten steroid sulfate glucuronide reference materials were synthesised through an ordered combination of chemical sulfation and/or enzymatic glucuronylation reactions. All compounds were purified and characterised using NMR and MS methods. Chemistry for the preparation of stable isotope labelled steroid {13C6}-glucuronide internal standards has also been developed and applied to the preparation of two selectively mono-labelled steroid bisglucuronide reference materials used to characterise more completely MS fragmentation pathways. The electrospray ionisation and fragmentation of the bisconjugated steroid reference materials has been studied. Preliminary targeted ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) analysis of the reference materials prepared revealed the presence of three steroid sulfate glucuronides as endogenous human urinary metabolites.
- Pranata, Andy,Fitzgerald, Christopher C.,Khymenets, Olha,Westley, Erin,Anderson, Natasha J.,Ma, Paul,Pozo, Oscar J.,McLeod, Malcolm D.
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supporting information
p. 25 - 40
(2019/01/04)
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- Steroid–Fullerene Hybrids from Epiandrosterone: Synthesis, Characterization and Theoretical Study
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New hybrid fullerene–steroid derivatives were prepared by using the Bingel–Hirsch protocol, by treatment of [60]fullerene with malonates bearing the appropriate steroid moieties obtained, in turn, from the functionalization of epiandrosterone, an important naturally occurring steroid hormone. Monocycloadduct C60-steroid conjugates were obtained by functionalization of ring A or ring D of the steroid moiety. We have also described the multistep preparation of a [60]fullerene hybrid dumbbell endowed with two fullerene units connected through an epiandrosterone molecule by a cyclopropanation reaction. The new compounds have been spectroscopically characterized and their redox potentials, determined by cyclic voltammetry, reveal three reversible reduction waves for monocycloadducts (8, 9 and 11, 12), whereas dumbbell-type derivative 10 exhibits the best electron-accepting abilities of the Bingel-type fullerene–steroid series. Theoretical calculations at semiempirical (AM1) and single point B3LYP-D3/6-31G+(d,p) levels have predicted the most stable conformations for the hybrid compounds and allow explaining the observed regioselectivity in the cyclopropanation reaction with dimalonate 7 during the synthesis of the dumbbell derivative.
- Almagro, Luis,Hernández-Castillo, David,Ortiz, Orlando,Alonso, Dayana,Ruiz, Alberto,Coro, Julieta,Herranz, María ángeles,Molero, Dolores,Martínez-álvarez, Roberto,Suárez, Margarita,Martín, Nazario
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p. 4512 - 4522
(2018/09/13)
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- Boosting the Catalytic Performance of Metal–Organic Frameworks for Steroid Transformations by Confinement within a Mesoporous Scaffold
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Solid-state crystallization achieves selective confinement of metal–organic framework (MOF) nanocrystals within mesoporous materials, thereby rendering active sites more accessible compared to the bulk-MOF and enhancing the chemical and mechanical stability of MOF nanocrystals. (Zr)UiO-66(NH2)/SiO2 hybrid materials were tested as efficient and reusable heterogeneous catalysts for the synthesis of steroid derivatives, outperforming the bulk (Zr)UiO-66(NH2) MOF. A clear correlation between the catalytic activity of the dispersed Zr sites present in the confined MOF, and the loading of the mesoporous SiO2, is demonstrated for steroid transformations.
- Cirujano, Francisco G.,Luz, Ignacio,Soukri, Mustapha,Van Goethem, Cedric,Vankelecom, Ivo F. J.,Lail, Marty,De Vos, Dirk E.
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supporting information
p. 13302 - 13306
(2017/10/17)
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- Rapid probing of the reactivity of P450 monooxygenases from the CYP116B subfamily using a substrate-based method
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Developing a detailed understanding of the reactivity of self-sufficient Type IV P450 monooxygenases, four types of O-methylated substrates were designed as probes, including monoterpenes, cycloalkanes, aromatic compounds and steroids, and the efficiency of their oxyfunction was determined using a colorimetric assay which was based on the reaction between the enzymatic demethylation product, formaldehyde, and Purpald dye. The activity-based fingerprints of new P450RpMO, P450ArMO and P450CtMO (CYP116B members) indicated that CYP116B P450s preferentially oxidize substrates with aromatic components. Moreover, the hydroxylated products were detected based on the preference results. This rapid and efficient strategy, when coupled with GCMS, enables the exploration of the reactivity of other CYP116B members.
- Li, Ren-Jie,Xu, Jian-He,Yin, Yue-Cai,Wirth, Nicolas,Ren, Jiang-Meng,Zeng, Bu-Bing,Yu, Hui-Lei
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supporting information
p. 8928 - 8934
(2016/10/13)
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- Allylic oxidation of steroidal olefins by vanadyl acetylacetonate and tert-butyl hydroperoxide
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Abstract Readily available vanadyl acetylacetonate was found to oxidize the allylic sites of Δ5 steroidal alcohols without protection of hydroxyl groups. Cholesterol, dehydroepiandrosterone, cholesterol benzoate, cholesterol acetate, pregnenolone, and 5-pregnen-3,20-diene were oxidized to 7-keto products using vanadyl acetylacetonate in one pot reactions at room temperature in the presence of oxygen and water.
- Grainger, Wendell S.,Parish, Edward J.
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p. 103 - 109
(2015/06/30)
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- Substrate specificity and inhibitor sensitivity of rabbit 20α-hydroxysteroid dehydrogenase
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In this study, we examined the substrate specificity and inhibitor sensitivity of rabbit 20α-hydroxysteroid dehydrogenase (AKR1C5), which plays a role in the termination of pregnancy by progesterone inactivation. AKR1C5 moderately reduced the 3-keto group of only 5α-dihydrosteroids with 17β- or 20α/β-hydroxy group among 3-ketosteroids. In contrast, the enzyme reversibly and efficiently catalyzed the reduction of various 17- and 20-ketosteroids, including estrogen precursors (dehydroepiandrosterone, estrone and 5α-androstan-3β- ol-17-one) and tocolytic 5β-pregnane-3,20- dione. In addition to the progesterone inactivation, the formation of estrogens and metabolism of the tocolytic steroid by AKR1C5 may be related to its role in rabbit parturition. AKR1C5 also reduced various non-steroidal carbonyl compounds, including isatin, an antagonist of the C-type natriuretic peptide receptor, and 4-oxo-2-nonenal, suggesting its roles in controlling the bioactive isatin and detoxification of cytotoxic aldehydes. AKR1C5 was potently and competitively inhibited by flavonoids such as kaempferol and quercetin, suggesting that its activity is affected by ingested flavonoids.
- Endo, Satoshi,Arai, Yuki,Hara, Akira,Kitade, Yukio,Bunai, Yasuo,El-Kabbani, Ossama,Matsunaga, Toshiyuki
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p. 1514 - 1518
(2013/10/08)
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- Rabbit 3-hydroxyhexobarbital dehydrogenase is a NADPH-preferring reductase with broad substrate specificity for ketosteroids, prostaglandin D2, and other endogenous and xenobiotic carbonyl compounds
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3-Hydroxyhexobarbital dehydrogenase (3HBD) catalyzes NAD(P) +-linked oxidation of 3-hydroxyhexobarbital into 3-oxohexobarbital. The enzyme has been thought to act as a dehydrogenase for xenobiotic alcohols and some hydroxysteroids, but its physiological function remains unknown. We have purified rabbit 3HBD, isolated its cDNA, and examined its specificity for coenzymes and substrates, reaction directionality and tissue distribution. 3HBD is a member (AKR1C29) of the aldo-keto reductase (AKR) superfamily, and exhibited high preference for NADP(H) over NAD(H) at a physiological pH of 7.4. In the NADPH-linked reduction, 3HBD showed broad substrate specificity for a variety of quinones, ketones and aldehydes, including 3-, 17- and 20-ketosteroids and prostaglandin D2, which were converted to 3α-, 17β- and 20α-hydroxysteroids and 9α,11β- prostaglandin F2, respectively. Especially, α-diketones (such as isatin and diacetyl) and lipid peroxidation-derived aldehydes (such as 4-oxo- and 4-hydroxy-2-nonenals) were excellent substrates showing low Km values (0.1-5.9 μM). In 3HBD-overexpressed cells, 3-oxohexobarbital and 5β-androstan-3α-ol-17-one were metabolized into 3-hydroxyhexobarbital and 5β-androstane-3α,17β-diol, respectively, but the reverse reactions did not proceed. The overexpression of the enzyme in the cells decreased the cytotoxicity of 4-oxo-2-nonenal. The mRNA for 3HBD was ubiquitously expressed in rabbit tissues. The results suggest that 3HBD is an NADPH-preferring reductase, and plays roles in the metabolisms of steroids, prostaglandin D2, carbohydrates and xenobiotics, as well as a defense system, protecting against reactive carbonyl compounds.
- Endo, Satoshi,Matsunaga, Toshiyuki,Matsumoto, Atsuko,Arai, Yuki,Ohno, Satoshi,El-Kabbani, Ossama,Tajima, Kazuo,Bunai, Yasuo,Yamano, Shigeru,Hara, Akira,Kitade, Yukio
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p. 1366 - 1375
(2013/11/19)
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- The regio- and stereo-selective reduction of steroidal 4-en-3-ones using Na2S2O4/NaHCO3 and CuCl/NaBH 4
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This paper describes the regio- and stereoselective reduction of a.
- Wang, Chunli,Chen, Xiaoyu,Huang, Yaoqing,Yang, Jesse,Chen, Ying
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p. 1339 - 1346
(2013/11/19)
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- Conversion of human steroid 5β-reductase (AKR1D1) into 3β-hydroxysteroid dehydrogenase by single point mutation E120H: Example of perfect enzyme engineering
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Human aldo-keto reductase 1D1 (AKR1D1) and AKR1C enzymes are essential for bile acid biosynthesis and steroid hormone metabolism. AKR1D1 catalyzes the 5β-reduction of Δ4-3- ketosteroids, whereas AKR1C enzymes are hydroxysteroid dehydrogenases (HSDs). These enzymes share high sequence identity and catalyze 4-pro-(R)-hydride transfer from NADPH to an electrophilic carbon but differ in that one residue in the conserved AKR catalytic tetrad, His120 (AKR1D1 numbering), is substituted by a glutamate in AKR1D1. We find that the AKR1D1 E120H mutant abolishes 5β-reductase activity and introduces HSD activity. However, the E120H mutant unexpectedly favors dihydrosteroids with the 5α-configuration and, unlike most of the AKR1C enzymes, shows a dominant stereochemical preference to act as a 3β-HSD as opposed to a 3α-HSD. The catalytic efficiency achieved for 3β-HSD activity is higher than that observed for any AKR to date. High resolution crystal structures of the E120H mutant in complex with epiandrosterone, 5β-dihydrotestosterone, and Δ4-androstene-3,17-dione elucidated the structural basis for this functional change. The glutamate-histidine substitution prevents a 3-ketosteroid from penetrating the active site so that hydride transfer is directed toward the C3 carbonyl group rather than the Δ4-double bond and confers 3β-HSD activity on the 5β-reductase. Structures indicate that stereospecificity of HSD activity is achieved because the steroid flips over to present its α-face to the A-face of NADPH. This is in contrast to the AKR1C enzymes, which can invert stereochemistry when the steroid swings across the binding pocket. These studies show how a single point mutation in AKR1D1 can introduce HSD activity with unexpected configurational and stereochemical preference.
- Chen, Mo,Drury, Jason E.,Christianson, David W.,Penning, Trevor M.
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experimental part
p. 16609 - 16622
(2012/07/30)
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- Characterization of rabbit aldose reductase-like protein with 3β-hydroxysteroid dehydrogenase activity
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In this study, we isolated the cDNA for a rabbit aldose reductase-like protein that shared an 86% sequence identity to human aldo-keto reductase (AKR)1 1B10 and has been assigned as AKR1B19 in the AKR superfamily. The purified recombinant AKR1B19 was similar to AKR1B10 and rabbit aldose reductase (AKR1B2) in the substrate specificity for various aldehydes and α-dicarbonyl compounds. In contrast to AKR1B10 and AKR1B2, AKR1B19 efficiently reduced 3-keto-5α/β-dihydro-C19/C21/C24-steroids into the corresponding 3β-hydroxysteroids, showing Km of 1.3-9.1 μM and kcat of 1.1-7.6 min-1. The stereospecific reduction was also observed in the metabolism of 5α- and 5β- dihydrotestosterones in AKR1B19-overexpressing cells. The mRNA for AKR1B19 was ubiquitously expressed in rabbit tissues, and the enzyme was co-purified with 3β-hydroxysteroid dehydrogenase activity from the lung. Thus, AKR1B19 may function as a 3-ketoreductase, as well as a defense system against cytotoxic carbonyl compounds in rabbit tissues. The molecular determinants for the unique 3-ketoreductase activity were investigated by replacement of Phe303 and Met304 in AKR1B19 with Gln and Ser, respectively, in AKR1B10. Single and double mutations (F303Q, M304S and F303Q/M304S) significantly impaired this activity, suggesting the two residues play critical roles in recognition of the steroidal substrate.
- Endo, Satoshi,Matsunaga, Toshiyuki,Kumada, Sho,Fujimoto, Airi,Hara, Akira,Ohno, Satoshi,El-Kabbani, Ossama,Hu, Dawei,Toyooka, Naoki,Mano, Jun'Ichi,Tajima, Kazuo
-
p. 23 - 30,8
(2020/08/20)
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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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- Stereospecific reduction of 5β-reduced steroids by human ketosteroid reductases of the AKR (aldo-keto reductase) superfamily: Role of AKR1C1-AKR1C4 in the metabolism of testosterone and progesterone via the 5β-reductase pathway
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Active sex hormones such as testosterone and progesterone are metabolized to tetrahydrosteroids in the liver to terminate hormone action. One main metabolic pathway, the 5β-pathway, involves 5β-steroid reductase (AKR1D1, where AKR refers to the aldo-keto reductase superfamily), which catalyses the reduction of the 4-ene structure, and ketosteroid reductases (AKR1C1-AKR1C4), which catalyse the subsequent reduction of the 3-oxo group. The activities of the four human AKR1C enzymes on 5β-dihydrotestosterone, 5β-pregnane-3,20-dione and 20α-hydroxy-5β-pregnan-3-one, the intermediate 5β-dihydrosteroids on the 5β-pathway of testosterone and progesterone metabolism, were investigated. Product characterization by liquid chromatography-MS revealed that the reduction of the 3-oxo group of the three steroids predominantly favoured the formation of the corresponding 3α-hydroxy steroids. The stereochemistry was explained by molecular docking. Kinetic properties of the enzymes identified AKR1C4 as the major enzyme responsible for the hepatic formation of 5β-tetrahydrosteroid of testosterone, but indicated differential routes and roles of human AKR1C for the hepatic formation of 5β-tetrahydrosteroids of progesterone. Comparison of the kinetics of the AKR1C1-AKR1C4-catalysed reactions with those of AKR1D1 suggested that the three intermediate 5β-dihydrosteroids derived from testosterone and progesterone are unlikely to accumulate in liver, and that the identities and levels of 5β-reduced metabolites formed in peripheral tissues will be governed by the local expression of AKR1D1 and AKR1C1-AKR1C3. The Authors Journal compilation 2011 Biochemical Society.
- Jin, Yi,Mesaros, A. Clementina,Blair, Ian A.,Penning, Trevor M.
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- Simultaneously rapid deprotection of 3-acyloxy groups and reduction of D-ring ketones (nitrile) of steroids using DIBAL-H/NiCl2
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An efficient preparation of hydroxysteroids by a one-pot, simultaneously rapid deprotection of 3-acyloxy groups and reduction of D-ring ketones (nitrile) of steroids using DIBAL-H in the presence of NiCl2 (10 mol %) is described. The attractive features of this procedure for the preparation of the hydroxysteroid derivatives are the mild reaction conditions, short reaction time, excellent yields, clean reaction profiles, and an inexpensive catalyst system.
- Wang, Xingbin,Liu, Hui,Yan, Peiyun,Liu, Jinliang,Li, Yan,Sun, Qian,Wang, Cunde
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experimental part
p. 291 - 293
(2011/10/05)
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- Liquid chromatography-mass spectrometry (LC-MS) of steroid hormone metabolites and its applications
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Advances in liquid chromatography-mass spectrometry (LC-MS) can be used to measure steroid hormone metabolites in vitro and in vivo. We find that LC-electrospray ionization (ESI)-MS using a LCQ ion trap mass spectrometer in the negative ion mode can be used to monitor the product profile that results from 5α-dihydrotestosterone (DHT)-17β-glucuronide, DHT-17β-sulfate, and tibolone-17β-sulfate reduction catalyzed by human members of the aldo-keto reductase (AKR) 1C subfamily and assign kinetic constants to these reactions. We also developed a stable isotope dilution LC-electron capture atmospheric pressure chemical ionization (ECAPCI)-MS method for the quantitative analysis of estrone (E1) and its metabolites as pentafluorobenzyl (PFB) derivatives in human plasma in the attomole range. The limit of detection for E1-PFB was 740. attomole on column. Separations can be performed using normal-phase LC because ionization takes place in the gas phase rather than in solution. This permits efficient separation of the regioisomeric 2- and 4-methoxy-E1. The method was validated for the simultaneous analysis of plasma E2 and its metabolites: 2-methoxy-E2, 4-methoxy-E2, 16α-hydroxy-E2, estrone (E1), 2-methoxy-E1, 4-methoxy-EI, and 16α-hydroxy-E1 from 5. pg/mL to 2000. pg/mL. Our LC-MS methods have sufficient sensitivity to detect steroid hormone levels in prostate and breast tumors and should aid their molecular diagnosis and treatment.
- Penning, Trevor M.,Lee, Seon-Hwa,Jin, Yi,Gutierrez, Alejandro,Blair, Ian A.
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experimental part
p. 546 - 555
(2011/12/02)
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- Hydrogenation of hindered ketones catalyzed by a silica-supported compact phosphine-Rh system
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(Chemical Equation Presented) A heterogeneous mono(phosphine)-Rh catalyst system silica-SMAP-Rh(OMe)(cod), where silica-SMAP stands for a caged, compact trialkylphosphine (SMAP) supported on silica gel, showed broad applicability toward the hydrogenation of hindered ketones. Doubly α-branched ketones such as diisopropyl ketone was hydrogenated under nearly atmospheric conditions. Di-tert-butyl ketone could be hydrogenated under more forcing conditions.
- Kawamorita, Soichiro,Hamasaka, Go,Ohmiya, Hirohisa,Hara, Kenji,Fukuoka, Atsushi,Sawamura, Masaya
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supporting information; scheme or table
p. 4697 - 4700
(2009/05/26)
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- Synthesis of 5α-androstan-3β,17β-diol from tigogenin
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5α-Androstan-3β,17β-diol (3b-adiol), a known inhibitor of prostate cancer cell growth, was synthesized from tigogenin. Its structure was confirmed by NMR and IR spectroscopy and mass spectroscopy. Springer Science+Business Media, Inc. 2007.
- Merlani,Amiranashvili,Men'Shova,Kemertelidze
-
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- Metal coordination-directed hydroxylation of steroids with a novel artificial P-450 catalyst
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A novel catalyst has been synthesized in which a manganese-porphyrin unit is linked to two 2,2′-bipyridyl groups and two pentafluorophenyl groups in trans fashion on its four meso positions. Relative to a previous catalyst in which the manganese-porphyrin had four 2,2′-bipyridyl groups, the new catalyst, in the presence of Cu2+ ions as coordinating linkers, catalyzes the oxidation of a steroid substrate with much better regioselectivity and higher turnover numbers.
- Fang, Zhenglai,Breslow, Ronald
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p. 251 - 254
(2007/10/03)
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- Substrate specificity of a mouse aldo-keto reductase (AKR1C12)
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AKR1C12, a mouse member of the aldo-keto reductase (AKR) superfamily, is highly expressed in the stomach and is identical to a protein encoded in an interleukin-3-regulated gene in mouse myeloid cells, but its function remains unknown. In this study, the recombinant AKR1C12 was purified to homogeneity and the specificity for coenzymes and substrates was examined at a physiological pH of 7.4. The enzyme reduced various α-dicarbonyl compounds, several ketosteroids, aldehydes and some ketones using NADH as the preferred coenzyme. In the reverse reaction, the enzyme showed coenzyme preference for NAD +, and oxidized 3α-, 17β- and 20α-hydroxysteroids, and non-steroidal aliphatic and alicyclic alcohols, of which many hydroxysteroids and geranylgeraniol were good substrates, exhibiting low K m and high kcat/Km values. The results, together with the intracellular high ratio of NAD+/NADH, suggest that AKR1C12 functions as a dehydrogenase for the endogenous hydroxysteroids and geranylgeraniol in mouse stomach and myeloid cells.
- Endo, Satoshi,Matsumoto, Kengo,Matsunaga, Toshiyuki,Ishikura, Shuhei,Tajima, Kazuo,El-Kabbani, Ossama,Hara, Akira
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p. 2488 - 2492
(2007/10/03)
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- Phosphine effects in the copper(I) hydride-catalyzed hydrogenation of ketones and regioselective 1,2-reduction of α,β-unsaturated ketones and aldehydes. Hydrogenation of decalin and steroidal ketones and enones
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The stereoselectivity and regioselectivity of the catalytic hydrogenation of ketones and α,β-unsaturated ketones and aldehydes using soluble copper(I) hydride catalysts have been investigated as a function of the ancillary phosphine ligand. While a relatively narrow range of aryldialkylphosphine ligands produce active hydrogenation catalysts, some ligands provide higher selectivity for 1,2-reduction of acyclic unsaturated carbonyl substrates than observed using the previously reported dimethylphenylphosphine-stabilized catalyst. The synthetic utility of this class of hydridic hydrogenation catalysts is illustrated by the hydrogenation of decalin and steroidal ketones and enones, the latter giving allylic alcohols with high selectivity. (C) 2000 Elsevier Science Ltd.
- Chen, Jian-Xin,Daeuble, John F.,Stryker, Jeffrey M.
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p. 2789 - 2798
(2007/10/03)
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- Steroid transformations with Exophiala jeanselmei var. lecanii-corni and Ceratocystis paradoxa
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The fungi Exophiala jeanselmei var. lecanii-corni [IMI (International Mycological Institute) 312989, UAMH (University of Alberta Microfungus Collection and Herbarium) 8783] and Ceratocystis paradoxa (IMI 374529, UAMH 8784) have been examined for their potential in steroid biotransformation. The study has determined that E. jeanselmei var. lecanii-corni effected overall anti-Markovnikov hydration on dehydroisoandrosterone, and side-chain degradation on a variety of pregnanes. Both ascomycetes were found to carry out redox reactions of alcohols and ketones as well as 1,4 reduction of α,β-unsaturated carbonyl systems.
- Porter, Roy B.R.,Gallimore, Winklet A.,Reese, Paul B.
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p. 770 - 779
(2007/10/03)
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- Practical synthesis of androgen: The efficient transformation of 17-oxo group to 17α-hydroxy group
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The present report describes the improved transformation of the 17-oxo group in 3β-acetoxy-5α-androstan-17-one to a 17α-hydroxy group. A mixture of 17α-acetoxy and 16-ene compounds, which are usually produced by the standard synthetic route, were treated with peracetic acid (epoxidation of the 16-ene compound) and then sodium borohydride-sodium hydroxide (reduction- hydrolysis) to give the desired 17α-hydroxy compound in much better yield than that in previous reports. Recrystallization of the crude product with cyclohexane-methanol gave the pure compound in 54% yield (total yield from starting ketone).
- Ohta, Tetsuo,Zhang, Huyue,Torihara, Yoshitaka,Hida, Takemasa,Furukawa, Isao
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p. 630 - 632
(2007/10/03)
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- The Stereochemistry of an Elimination Reaction accompanying the Hydroboration of a Steroidal Allylic Alcohol
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Deuterium labelling studies have shown that the facile elimination of the 5β-hydroxy group observed in the course of hydroboration of a 5β-hydroxyandrost-3-ene may involve a trans diaxial borane-borinate elimination coupled with a syn transfer of hydrogen from the borinate.
- Hanson, James R.,Liman, Mansur D.,Uyanik, Cavit
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p. 126 - 127
(2007/10/03)
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- The hydroxylation of some 13α-methylsteroids by Cephalosporium aphidicola
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The Fungus, Cephalosporium aphidicola, has been shown to hydroxylate 5α,13α-androstan-3,17-dione and the 3β-alcohol at the C-1α and C-7α positions, whereas the corresponding compounds in the normal 13β-methyl series are hydroxylated at the C-11α and C-14α positions. Both series were hydroxylated at the 5α position. There was some epimerization of the axial 3α-alcohols to the equatorial 3β-epimers.
- Boynton, Juliette,Hanson, James R.,Hunter, A. Christy
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p. 951 - 956
(2007/10/03)
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- Regio- And Stereo-chemical Effects in the Hydroboration of Δ2-Steroidal Allylic and Homoallylic Alcohols
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A comparison between the hydroboration of δ2-steroidal 1x-allylic and 5x-homoallylic alcohols reveals that whereas both have a stereochemical directing effect, only the allylic alcohol modifies the regiospecificity of the reaction.
- Hanson, James R.,Liman, Mansur D.,Nagaratnam, Sivajini
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p. 282 - 283
(2007/10/03)
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- Regioselectivity in the Hydroboration of Steroidal δ3-Allylic Alcohols
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The presence of an allylic 5α-hydroxy group in an androst-3-ene increases the proportion of addition of a borane to the adjacent C-4 compared to the unsubstituted steroid and directs the addition to the face of the alkene anti to the hydroxy group with stereochemical effects that may oppose those of the C-10β-methyl group.
- Alam, Muzaffar,Hanson, James R.,Liman, Mansur,Nagaratnam, Sivajini
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- The Diastereoselectivity of Zirconium Alkoxide Catalysed Meerwein-Ponndorf-Varley Reductions
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The new variation of the Meerwein-Ponndorf-Verley reduction using 1-ethanol (6) or 1-tetralol (12) (3 equiv.) as the reducting alcohols and Zr(OtBu)4 as the catalyst (0.2 equiv.) is kinetically controlled and highly stereoselective.Preferential axial attack is achieved with the sterically less bulky alcohol 6 in the case of 4-tert-butyl- and 3-methylcyclohexanones (1a -> 96percent axial and 3a -> 93percent axial attack).The combination tetralol (12)/Zr(OtBu)4 behaves as a very bulky reducting agent, and the thermodynamically less stable alcohols 2c (80percent) and 4c (92 - 96percent) are formed preferentially in the reduction of 2a and 4b.The fused bicyclic systems 1-methyl-2-tetralone (14a) and flavanone (15a) and the steroids 16a-18a are reduced with high stereoselectivity to the corresponding cis alcohols 14b and 15b and the β-alcohols 16b-18b.The stereochemical outcome is in agreement with the Felkin-Ahn model. - Key Words: Reduction / Meerwein-Ponndorf-Verley reduction / Catalysis / Zirconium tetra-tert-butoxide / Stereochemistry / Diastereoselectivity / Felkin-Ahn model
- Krohn, Karsten,Knauer, Birgit
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p. 1347 - 1352
(2007/10/02)
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- Facial selectivity in the hydroboration of androst-4-enes
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In the absence of an allylic hydroxy group, the stereochemistry of hydroboration of an androst-4-ene is determined by the presence and stereochemistry of the C-10 methyl group.Allylic hydroxy groups at C-3 direct the hydroboration/oxidation to the anti-face.In the case of the 3α-alcohol, this effect is in opposition to the normal hydration from the α-face of the steroid and leads to the 4β-alcohol.The stereochemistry of 4β,17β-diacetoxy-19-nor-5β-androstane was established by X-ray crystallography.
- Hanson, James R.,Hitchcock, Peter B.,Liman, Mansur D.,Naragatnam, Sivajini
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p. 2183 - 2188
(2007/10/02)
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- Triethylamine-photosensitized reduction of a ketone via a chemical sensitization mechanism
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Photolysis of acetonitrile solutions of 3β-hydroxy-5α-androstan-17-one (1), or its 3β-methoxy analogue (5), and triethylamine (TEA) with 254-nm light leads to reduction of the 17-keto group with high stereoselectivity. By contrast, Norrish type I products are exclusively observed when the photolysis is carried out in cyclohexane, and products from both α-cleavage and reduction are observed in ether or THF. Excitation of TEA in acetonitrile results in the photoionization of the amine to form a radical cation and a solvent radical anion. Several possible mechanisms for reduction of ground-state ketones by these species, or radicals derived therefrom, are outlined. The limiting quantum efficiency for reduction of 1 is 0.17. The results observed in cyclohexane are explained by singlet-singlet energy transfer from the TEA excited state to the ketone, while both photoionization and energy transfer appear to be operating in the ethereal solvents.
- Wu, Zheng-Zhi,Hug, Gordon L.,Morrison, Harry
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p. 1812 - 1816
(2007/10/02)
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- 17-Hydroxy-steroids
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Compounds of the formulae: STR1 are useful as anti-cancer, anti-obesity, anti-diabetic, anti-coronary agents, anti-aging agents, anti-hypolipidemic agents and anti-autoimmune agents.
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- The Reduction of Steroid 2α-Fluoro 4-En-3-ones
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Reduction of testosterone with potassium tri-(R,S)-sec-butylborohydride gives predominantly the allylic 3β-alcohol, while 2α-fluorotestosterone is converted solely to 2α-fluoro-4-androstene-3α,17β-diol, and 2α-fluoro-4-androstene-3,17-dione to 2α-fluoro-3α-hydroxy-4-androsten-17-one.Reduction of testosterone with (R,R)- or (S,S)-Rh-DIOP and dihydrosilanes give predominantly allylic alcohols, while with the same catalysts and monohydrosilanes no allylic alcohols are found, the 4-double bond being instead reduced.The chirality of the DIOP reagents contributes only to a minor extent to stereoselectivity of 3-ketone reduction.
- Goeendos, Gyoergy,McGirr, Larry G.,Jablonski, Chester R.,Snedden, Walter,Orr, James C.
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p. 3057 - 3059
(2007/10/02)
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- Isolation of 3β,20α-hydroxysteroid oxidoreductase from sheep fetal blood
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3β,20α-Hydroxysteroid oxidoreductase has been isolated from ovine fetal blood by a 2,370-fold purification scheme of ammonium sulfate fractionation, calcium phosphate gel adsorption, affinity chromatography, and fast performance liquid chromatography. A new high performance liquid chromatography-based assay for measuring 20α-reductase activity is described. The enzyme is a monomer with a molecular weight of 35,000 and uses NADPH as a cofactor for reductase activity. It reduces progesterone to 4-pregnan-20α-ol-3-one or 5α-dihydrotestosterone to 5α-androstan-3β,17β-diol with kinetic characteristics of Km = 30.8 μM and Vmax = 0.7 nmol min-1 (nmol of enzyme)-1 or Km = 74 μM and Vmax = 1.3 nmol min-1 (nmol of enzyme)-1, respectively. 5α-Dihydrotestosterone competitively inhibits 20α-reductase activity with a Ki value of 102 μM.
- Chen,Nancarrow,Sweet
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p. 477 - 496
(2007/10/02)
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- STUDIES ON THE KINETICS OF THE INTERACTION OF 7α-HYDROXYTESTOSTERONE WITH THE STEROID 5α-REDUCTASE
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Microsomal preparations from adult male rat testicular interstitial cells were incubated with tritiated testosterone.Added 7α-hydroxytestosterone, (7α,17β-dihydroxy-4-androsten-3-one), at levels which appear to exist in the adult testis, inhibited production of labelled 5α-reduced steroids in a graded fashion.This interaction is not competitive and occurs only at high substrate levels, such as those found in steroid-producing organs.Relationships to pubertal changes in steroid metabolism are discussed.
- Mittler, James C.
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p. 135 - 142
(2007/10/02)
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- STUDY OF THE DIRECT EFFECT OF LHRH AGONIST ON TESTICULAR 17-HYDROXYLASE AND 5α-REDUCTASE ACTIVITIES IN NON-HYPOPHYSECTOMIZED ADULT RATS TREATED WITH AN ANTI-LUTEINIZING HORMONE SERUM
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In order to study both direct and pituitary-mediated mechanisms of action of the LHRH analogue 6, des-Gly-NH210>LHRH ethylamide upon testicular steroidogenesis in adult rat, we compared the effects of the agonist when administered alone or concomitantly with an anti-LH serum to non-hypophysectomized rats.Testicular steroid contents and in vitro progesterone and testosterone metabolism were determined.Anti-LH serum administration was able to prevent 5α-reductase stimulation by the agonistic peptide, but not the inhibition of 17-hydroxylase activity.These data suggest that modulation of 17-hydroxylase involves both direct and pituitary-mediated processes, while 5α-reductase stimulation is mainly if not only due to a pituitary-mediated mechanism.
- Carmichael, Rejean,Belanger, Alain
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- Favorskii Rearrangements of α-Halogenated Acetylcycloalkanes. 4. Stereochemistry of Cyclopropanonic Rearrangements and the Influence of Steric Factors on the Competing Formation of α-Hydroxy Ketones
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It is shown that the marked stereoselectivity, in favor of 17α-methylated etio acid derivatives, of Favorskii rearrangements in protic and polar media of 17-brominated 20-keto steroids - somewhat diminished by a bulky 12α-substituent, such as an acetoxy group - is due, to an appreciable extent, to the influence of the 18-methyl group.Thus, the rearrangement of 17-bromo-3β-acetoxy-18-nor-5α-pregnan-20-one, which was synthesized from 3β-acetoxy-5α-androstan-17-one, proceeds with potassium bicarbonate in aqueous methanol much less stereoselectively than analogous rearrang ements of 13-methylated 17-bromo 20-ketones, and in its reaction with potassium methoxide in absolute methanol the yield of the 17β-methyl 17α-etio ester even exceeds that of the 17α-methylated rearrangement product, in contradistinction to the results of equivalent reactions of 13-methylated substrates.It is also shown that in the absence of the 18-methyl group a 17β-hydroxy 20-ketonic substitution product and related adducts are obtained in high proportion, and it is concluded that the quasi-absence of such products in analogous reactions of 13-methylated 17-bromo 20-keto steroids is essentially due to the steric impediment exerted by this group to the formation of intermediate epoxy ethers.The results presented agree with the hypothesis of a competition between concerted and nonconcerted cyclopropanone formations from α-halo enolates, in part dependent on the polarity and protonicity of the medium, or possibly with that of gradients of mechanisms, and they support the intermediacy of epoxy ethers in the formation of α-hydroxy ketones as side products of Favorskii rearrangements.
- Engel, Ch. R.,Lachance, P.,Capitaine, J.,Zee, J.,Mukherjee, D.,Merand, Y.
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p. 1954 - 1966
(2007/10/02)
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- Microbiological Transformations. XVI. Transformation of 5α- and 5β-Dihydro, and 1- and 6-Dehydro Derivatives of Testosterone and Androstenedione by Means of Rhodotorula mucilaginosa Strain
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The following transformation of 5α- and 5β-dihydro derivatives of testosterone and androstenedione by means of Rhodotorula mucilaginosa has been observed: reduction of the carbonyl group on C-3 to both possible alcohols in the 5α-series and only to one alcohol (3α) in the 5β-series.In the transformation of 1- and 6-dehydro derivatives of testosterone and androstenedione, reduction in ring A was completely inhibited.The carbonyl or hydroxy groups at C-17 in both series of substrates underwent interconversion.
- Draczynska, Bozena,Tlomak, Elzbieta,Dmochowska-Gladysz, Jadwiga,Siewinski, Antoni
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- Lanthanoids in Organic Synthesis. 6. The Reduction of α-Enones by Sodium Borohydride in the Presence of Lanthanoid Chlorides: Synthetic and Mechanistic Aspects
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Lanthanoid chlorides (LnCl3) are efficient catalysts for the regioselective 1,2-reduction of α-enones by NaBH4 in methanol solution.Optimal conditions of this reaction have been determined.A mechanistic interpretation depicting the role of the Ln3+ ions is given.The major effect of Ln3+ is the catalysis of BH4- decomposition by the hydroxylic solvent to afford alkoxyborohydrides, which may be responsible for the observed regioselectivity.The stereoselectivity of the process is also modified by the presence of the Ln3+ ions, in that axial attack of cyclohexanone systems is enhanced.
- Gemal, Andre L.,Luche, Jean-Louis
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p. 5454 - 5459
(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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