- Cloning, characterization, and expression analysis of a putative 17 beta-hydroxysteroid dehydrogenase 11 in the abalone, Haliotis diversicolor supertexta
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The 17-beta-hydroxysteroid dehydrogenases (17β-HSDs) are key enzymes for sex steroid biosynthesis. To date, relatively little is known about the presence and function of 17β-HSDs in marine gastropods. In the present study, a cDNA sequence encoding putative 17β-HSD type 11 (17β-HSD-11) was identified in marine abalone (Haliotis diversicolor supertexta). The full-length cDNA contains 1058 bp, including an open reading frame (ORF) of 900 bp that encodes a protein of 299 amino acids. Comparative structural analysis revealed that abalone 17β-HSD-11 shares relatively high homology with other 17b-HSD-11 hormologues, and a lesser degree of amino acid identity with other forms of 17b-HSD, especially in the functional domains, including the cofactor binding domain (TGxxxGxG) and catalytic site (YxxSK). Phylogenetic analysis showed that abalone 17β-HSD-11 belongs to the short-chain dehydrogenase/reductase (SDR) family. Functional analysis following transient transfection of the ORF into human embryonic kidney-293 (HEK-293) cells indicated that abalone 17β-HSD-11 has the ability to convert 5α-androstane-3α,17β-diol (3α-diol) to androsterone (A) and testosterone (T) to androstenedione (4A). Expression analysis in vivo demonstrated that abalone 17β-HSD-11 is differentially expressed during three stages (non-reproductive, reproductive, and post-reproductive). Taken together, these results indicate that ab-17β-HSD-11 is an SDR family member with a potential role in steroid regulation during the reproductive stage.
- Zhai, Hong-Ning,Zhou, Jin,Cai, Zhong-Hua
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Read Online
- Convenient stereoselective synthesis of some 3-aminosteroid scaffolds
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An efficient stereoselective synthesis 3α- and 3β-aminoandrostan-17-one and 3α-amino dehydroepiandrosten-17-one based on a Mitsunobu reaction has been developed, using azide as the ammonia equivalent. All the products were isolated in high yield.
- Solum, Eirik Johansson,Mohamed, Yasser Mahmoud A.
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Read Online
- Photoinduced Deoxygenative Borylations of Aliphatic Alcohols
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A photochemical method for converting aliphatic alcohols into boronic esters is described. Preactivation of the alcohol as a 2-iodophenyl-thionocarbonate enables a novel Barton–McCombie-type radical deoxygenation that proceeds efficiently with visible light irradiation and without the requirement for a photocatalyst, a radical initiator, or tin or silicon hydrides. The resultant alkyl radical is intercepted by bis(catecholato)diboron, furnishing boronic esters from a diverse range of structurally complex alcohols.
- Wu, Jingjing,B?r, Robin M.,Guo, Lin,Noble, Adam,Aggarwal, Varinder K.
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p. 18830 - 18834
(2019/11/22)
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- Catalytic removal of tert-butyldimethylsilyl (TBS) ether by PVP-I
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A mild, efficient and rapid protocol the deprotection of alcoholic TBDMS ethers using PVP-1 as catalyst in methanol, the procedure of deprotection of various TBDMS ethers were found to be very convenient, easy work-up, high yielding.
- Ke, Yanxiong,Lu, Guangying,Ren, Jiangmeng,Wang, Di,Zeng, Bu-Bing
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- Steroid compound 3-site hydroxyl configuration inversion method
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The invention discloses a steroid compound 3-site hydroxyl configuration inversion method. The method specifically comprises the following steps that (1) a steroid compound containing a 3-site hydroxyl reacts with an acyl chloride compound; (2) the product obtained in the step (1) and a substituting agent are subjected to SN2 nucleophilic substitution reaction under existing of a phase transfer catalyst; and (3) the product obtained in the step (2) is subjected to a hydrolysis reaction. Compared with a Mitsunobu method, the method does not need to use triphenylphosphine and azodiformate pricedhigher, and accordingly the production cost is greatly lowered; meanwhile, a p-nitrobenzoic acid derivative which seriously affects the water environment does not need to be used, and therefore the method is more environmentally friendly. The method adopts cesium acetate/18-crown ether-6 system to conduct 3-site hydroxyl configuration inversion, can remarkably reduce occurrence of side reactions,accordingly a higher reaction yield is obtained, and the method is finally applicable to industrialized production.
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Paragraph 0025; 0030; 0031
(2018/12/14)
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- Stereo selective one-step reduction in the steroid skeleton 4 - ene -3 - ketone as a 3 α - hydroxy - 5 β - hydrogen A/B cis structure method
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The invention relates to a method for one-step reduction of a 4-ene-3-one structure in a steroid skeleton into an A/B cis-3a-hydroxy-5b-hydrogen structure, belonging to the fields of organic chemistry and drug synthesis. According to the method, under the conditions of room temperature and an environment of absolute ethyl alcohol, cuprous chloride is used as a catalyst and sodium borohydride is used as a reducing agent for high-selectivity conversion of the 4-ene-3-one structure of 4-AD, ADD and derivatives thereof into the A/B cis-3a-hydroxy-5b-hydrogen structure. According to results of X-diffraction results, an androstane-3a-hydroxy-5b-hydrogen-17-one product prepared by using the method has a stereo structure; reaction conditions are mild and simple; used reagents are cheap and easily available; operation is convenient; good repeatability is realized, and high yield is obtained. The method provided by the invention lays a good foundation for exploitation of resourceful utilization of sterol and for research on synthesis of drugs like ursodesoxycholic acid, chenodeoxycholic acid, deoxycholic acid and ecdyson with the A/B cis-structure with non-cholic acid type steroids as raw materials.
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Paragraph 0022; 0041; 0042; 0043
(2017/02/17)
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- Aldo-keto Reductase 1B15 (AKR1B15): A mitochondrial human aldo-keto reductase with activity toward steroids and 3-keto-acyl-CoA conjugates
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Alto-keto reductases (AKRs) comprise a superfamily of proteins involved in the reduction and oxidation of biogenic and xenobiotic carbonyls. In humans, at least 15 AKR superfamily members have been identified so far. One of these is a newly identified gene locus, AKR1B15, which clusters on chromosome 7 with the other human AKR1B subfamily members (i.e. AKR1B1 and AKR1B10). We show that alternative splicing of the AKR1B15 gene transcript gives rise to two protein isoforms with different N termini: AKR1B15.1 is a 316-amino acid protein with 91% amino acid identity to AKR1B10; AKR1B15.2 has a prolonged N terminus and consists of 344 amino acid residues. The two gene products differ in their expression level, subcellular localization, and activity. In contrast with other AKR enzymes, which are mostly cytosolic, AKR1B15.1 co-localizes with the mitochondria. Kinetic studies show that AKR1B15.1 is predominantly a reductive enzyme that catalyzes the reduction of androgens and estrogens with high positional selectivity (17β-hydroxysteroid dehydrogenase activity) as well as 3-ketoacyl-CoA conjugates and exhibits strong cofactor selectivity toward NADP(H). In accordance with its substrate spectrum, the enzyme is expressed at the highest levels in steroid-sensitive tissues, namely placenta, testis, and adipose tissue. Placental and adipose expression could be reproduced in the BeWo and SGBS cell lines, respectively. In contrast, AKR1B15.2 localizes to the cytosol and displays no enzymatic activity with the substrates tested. Collectively, these results demonstrate the existence of a novel catalytically active AKR, which is associated with mitochondria and expressed mainly in steroid-sensitive tissues.
- Weber, Susanne,Salabei, Joshua K.,M?ller, Gabriele,Kremmer, Elisabeth,Bhatnagar, Aruni,Adamski, Jerzy,Barski, Oleg A.
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p. 6531 - 6545
(2015/03/30)
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- Characterization of hamster NAD+-dependent 3(17)β-hydroxysteroid dehydrogenase belonging to the aldo-keto reductase 1C subfamily
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The cDNAs for morphine 6-dehydrogenase (AKR1C34) and its homologous aldo-keto reductase (AKR1C35) were cloned from golden hamster liver, and their enzymatic properties and tissue distribution were compared. AKR1C34 and AKR1C35 similarly oxidized various xenobiotic alicyclic alcohols using NAD+, but differed in their substrate specificity for hydroxysteroids and inhibitor sensitivity. While AKR1C34 showed 3α/17β/20α-hydroxysteroid dehydrogenase activities, AKR1C35 efficiently oxidized various 3β- and 17β-hydroxysteroids, including biologically active 3β-hydroxy-5α/β-dihydro-C19/C21-steroids, dehydroepiandrosterone and 17β-estradiol. AKR1C35 also differed from AKR1C34 in its high sensitivity to flavonoids, which inhibited competitively with respect to 17β-estradiol (Ki 0.11-0.69 μM). The mRNA for AKR1C35 was expressed liver-specific in male hamsters and ubiquitously in female hamsters, whereas the expression of the mRNA for AKR1C34 displayed opposite sexual dimorphism. Because AKR1C35 is the first 3(17)β-hydroxysteroid dehydrogenase in the AKR superfamily, we also investigated the molecular determinants for the 3β-hydroxysteroid dehydrogenase activity by replacement of Val54 and Cys310 in AKR1C35 with the corresponding residues in AKR1C34, Ala and Phe, respectively. The mutation of Val54Ala, but not Cys310Phe, significantly impaired this activity, suggesting that Val54 plays a critical role in recognition of the steroidal substrate.
- Endo, Satoshi,Noda, Misato,Ikari, Akira,Tatematsu, Kenjiro,El-Kabbani, Ossama,Hara, Akira,Kitade, Yukio,Matsunaga, Toshiyuki
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p. 425 - 434
(2015/11/27)
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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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- Novel steroid inhibitors of glucose 6-phosphate dehydrogenase
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Novel derivatives of the steroid DHEA 1, a known uncompetitive inhibitor of G6PD, were designed, synthesized, and tested for their ability to inhibit this dehydrogenase enzyme. Several compounds with approximately 10-fold improved potency in an enzyme assay were identified, and this improved activity translated to efficacy in a cellular assay. The SAR for steroid inhibition of G6PD has been substantially developed; the 3β-alcohol can be replaced with 3β-H-bond donors such as sulfamide, sulfonamide, urea, and carbamate. Improved potency was achieved by replacing the androstane nucleus with a pregnane nucleus, provided a ketone at C-20 is present. For pregnan-20-ones incorporation of a 21-hydroxyl group is often beneficial. The novel compounds generally have good physicochemical properties and satisfactory in vitro DMPK parameters. These derivatives may be useful for examining the role of G6PD inhibition in cells and will assist the future design of more potent steroid inhibitors with potential therapeutic utility.
- Hamilton, Niall M.,Dawson, Martin,Fairweather, Emma E.,Hamilton, Nicola S.,Hitchin, James R.,James, Dominic I.,Jones, Stuart D.,Jordan, Allan M.,Lyons, Amanda J.,Small, Helen F.,Thomson, Graeme J.,Waddell, Ian D.,Ogilvie, Donald J.
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p. 4431 - 4445
(2012/09/11)
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- MEDICINAL APPLICATIONS OF BENZOIC ACID HYDRAZONES SYNTHESIZED ON THE BASIS OF STEROIDAL TIGOGENIN
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Novel benzoic acid hydrazones of 5α-androstan-3,17-dione have been prepared on the basis of steroidal tigogenin of the plant Yucca gloriosa. The hydrazones of the General Formula (I), General Formula (II) and General Formula (III) as shown in the accompanying FIGURE of the drawing are synthesized. The hydrazones have shown promising anti-T.B., anti-cancer and anti-HIV activity revealing immense potential as more efficacious, less toxic drugs with fewer undesirable side effects. They could also prove valuable in correcting hormonal abnormalities that cause severe health problems.
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Page/Page column 2
(2011/08/04)
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- Transformation of a series of saturated isomeric steroidal diols by Aspergillus tamarii KITA reveals a precise stereochemical requirement for entrance into the lactonization pathway
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Four isomers of 5α-androstan-3,17-diol have been transformed by the filamentous fungus Aspergillus tamarii, an organism which has the ability to convert progesterone to testololactone in high yield through an endogenous four step enzymatic pathway. The only diol handled within the lactonization pathway was 5α-androstan-3α,17β-diol which, uniquely underwent oxidation of the 17β-alcohol to the 17-ketone prior to its Baeyer-Villiger oxidation and the subsequent production of 3α-hydroxy-17a-oxa-D-homo-5α-androstan-17-one. This demonstrated highly specific stereochemical requirements of the 17β-hydroxysteroid dehydrogenase for oxidation of this specific steroidal diol to occur. In contrast, the other three diols were transformed within the hydroxylation pathway resulting in functionalization at C-11β. Only 5α-androstan-3β,17α-diol could bind to the hydroxylase in multiple binding modes undergoing monohydroxylation in 6β and 7β positions. Evidence from this study has indicated that hydroxylation of saturated steroidal lactones may occur following binding of ring-D in its open form in which an α-alcohol is generated with close spatial parity to the C-17α hydroxyl position. All metabolites were isolated by column chromatography and were identified by 1H, 13C NMR and DEPT analysis and further characterized using infra-red, elemental analysis and accurate mass measurement.
- Hunter, A. Christy,Collins, Catherine,Dodd, Howard T.,Dedi, Cinzia,Koussoroplis, Salomé-Juliette
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experimental part
p. 352 - 358
(2011/11/12)
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- Biotransformation of testosterone and progesterone by Penicillium digitatum MRC 500787
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The biotransformation of testosterone and progesterone by Penicillium digitatum MRC 500787 for 5 days is described. The biotransformation of testosterone afforded 5α-androstane-3,17-dione, 3α-hydroxy-5α- androstan-17-one, 3β-liydroxy-5α-androstan-17-one and androst-4-ene-3,17-dione. The biotransformation of progesterone afforded 5α-pregnane- 3,20-dione.
- Yildirim, Kudret,Gulsan, Fatih,Kupcu, Ilknur
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experimental part
p. 675 - 683
(2011/08/03)
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- Investigation on the regioselectivities of intramolecular oxidation of unactivated C-H bonds by dioxiranes generated in Situ
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We found that dioxiranes generated in situ from ketones 1-6 and Oxone underwent intramolecular oxidation of unactivated C-H bonds at δ sites of ketones to yield tetrahydropyrans. From the trans/cis ratio of oxidation products 1a and 2a as well as the retention of the configuration at the δ site of ketone 5, we proposed that the oxidation reaction proceeds through a concerted pathway under a spiro transition state. The intramolecular oxidation of ketone 6 showed the preference for a tertiary δ C-H bond over a secondary one. This intramolecular oxidation method can be extended to the oxidation of the tertiary γ′ C-H bond of ketones 9 and 10. For ketone 11 with two δ C-H bonds and one γ′ C-H bond linked respectively by a sp3 hydrocarbon tether and a sp2 ester tether, the oxidation took place exclusively at the δ C-H bonds. Finally, by introducing proper tethers, regioselective hydroxylation of steroid ketones 12-14 have been achieved at the C-17, C-16, C-3, and C-5 positions.
- Wong, Man-Kin,Chung, Nga-Wai,He, Lan,Wang, Xue-Chao,Yan, Zheng,Tang, Yeung-Chiu,Yang, Dan
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p. 6321 - 6328
(2007/10/03)
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- ANDROSTANE AND PREGNANE SERIES FOR ALLOSTERIC MODULATION OF GABA RECEPTOR
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Methods, compositions, and compounds for modulating the GABAA receptor-chloride ionophore complex to alleviate stress, anxiety, seizures, mood disorders, PMS and PND and to induce anesthesia.
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- Microbial transformations of testosterone to 5α-dihydrotestosterone by two species of Penicillium: P. chrysogenum and P. crustosum
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Two species of Penicillium - P. chrysogenum and P. crustosum - were cultured in presence of [3H]testosterone as a substrate. Both species were shown to reduce the 4,5-double bond in testosterone to give dihydrotestosterone (DHT). The steroids produced were 5α- dihydrotestosterone, DHT, 3α-hydroxy-5β-androstan-17-one, 3α-hydroxy-5α- androstan-17-one, 4-androstene-3,17-dione, and 5α-androstane-3,17-dione. These products implicate the presence of the 5α-reductase, with maximal activity at pH 6 and 8, in both species of Penicillium. The presence of DHT in the growth medium and not in the mycelium suggests that DHT is excreted into the medium.
- Cabeza, Marisa S.,Gutierrez, Edgar B.,Garcia, Genoveva A.,Avalos, Angeles H.,Hernandez, Miguel Angel H.
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p. 379 - 384
(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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- Solvent free tetrahydropyranylation of phenols and alcohols over zeolites HSZ as reusable catalysts
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Phenols and alcohols are tetrahydropyranylated in the presence of zeolites HSZ in good to excellent yields and selectivities. Addition of methanol performs the complete deprotection.
- Ballini, Roberto,Bigi, Franca,Carloni, Silvia,Maggi, Raimondo,Sartori, Giovanni
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p. 4169 - 4172
(2007/10/03)
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- Heterogeneous Catalysis in Carbonyl Regeneration from 1,3-Dithiolanes and 1,3-Dithianes by Zirconium Sulfophenyl Phosphonate
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Layered zirconium sulfophenyl phosphonate was found to be an efficient heterogeneous catalyst for mild hydrolysis of 1,2 dithiolanes and 1,3 dithianes to their corresponding carbonyl compounds.
- Curini, Massimo,Marcotullio, Maria Carla,Pisani, Emanuela,Rosati, Ornelio,Costantino, Umberto
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p. 769 - 770
(2007/10/03)
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- PREPARATION OF UNLABELLED AND 3H>-LABELLED EPITESTOSTERONE AND ITS METABOLITES
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Cold as well as 3H>-labelled substrates and metabolites IX-XI, XV, XVI, XX-XXII, XXIV, XXV and XXVIII were prepared by catalytic hydrogenation of epitestosterone (VIII) and Λ1-dehydroepitestosterone (XIII).The key step in the preparation of compound XXVIII was reaction of 3β-tosylates XXVI and XXX with potassium nitrite in dimethyl sulfoxide.
- Kasal, Alexander,Fuksova, Kveta,Pouzar, Vladimir
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p. 600 - 611
(2007/10/02)
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- 16-substituted androstanes and 16-substituted androstenes
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Compounds of the formula: 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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- Homoandrostan-17-one and homoandrosten-17-ones
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Compounds of the formula: STR1 useful as anti-cancer agents, anti-obesity agents, anti-hyperglycemic agents, anti-aging agents, anti-hyperglycemic agents and anti-autoimmune agents.
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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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- A New Procedure for Dethioacetalization via Equilibrium Exchange with Aqueous Acetone, Paraformaldehyde and Amberlyst 15 as Acidic Catalyst
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Carbonyl compounds were regenerated from corresponding Ethanediyl S,S-Acetals via equilibrium exchange with aqueous acetone, paraformaldehyde and Amberlyst 15, as acidic catalyst, at 80 deg C.
- Ballini, Roberto,Petrini, Marino
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p. 336 - 337
(2007/10/02)
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- STEROIDS. LIV. SYNTHESIS OF 17β-AMINO-5α-ANDROSTAN-3α-OL FROM EPIANDROSTERONE
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17β-Amino-3α-hydroxy-5α-androstane was synthesized from epiandrosterone by: a) epimerization at C3 by the Luttrell-Lochaus method to androsterone followed by reductive amination; b) Leuckart-Wallach amination followed by epimerization of the 3β-hydroxy-17β-formamido-5α-androstane at C3 by the Mitsunobu method.
- Nadaraia, N. Sh.,Sladkov, V. I.,Suvorov, N. N.
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p. 682 - 686
(2007/10/02)
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- Cerium(IV)-Mediated Synthesis of Tetrahydrofuranyl Ethers
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The reaction of tetrahydrofuran with an alcohol in the presence of ceric triethylammonium nitrate provides a convenient and general procedure for protecting the hydroxyl function.Tetrahydrofuranyl ethers of primary, secondary and tertiary alcohols were obtained in good yields.
- Maione, Anna M.,Romeo, A.
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p. 250 - 251
(2007/10/02)
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- REGIOSELECTIVE REDUCTION OF POLYKETONES ON SILICA GEL SURFACE WITH BORANE-TRIMETHYLAMINE COMPLEX
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Steroidal diones and trione, bicyclic diones (7 and 8) and a tricyclic dione were adsorbed on silica gel and reduced with BH3*NMe3.The carbonyl groups at C-3 of the steroids, at C-4 of 7 and at C-3 of 8 were reduced regioselectively.The FT-IR spectra of 5α- and 5β-androstane-3,17-dione adsorbed on silica gel were measured.
- Gohzu, Shun-ichi,Tada, Masahiro
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- Partial Purification and Characterization of Two β-Glucoronidases from Alcaligenes NG-11
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A strain of Alcaligenes isolated from soil was a good producer of β-glucuronidase, and the enzyme was purified from the cell-free extract by sequential column chromatography on DEAE-Toyopearl, Toyopearl HW-55F, and Phenyl-Sepharose CL-4B.By these procedures, two β-glucuronidases designated as β-glucuronidases I and II were purified 240- and 508-fold, respectively. β-Glucuronidase I, with a molecular weight of 75,000, had an optimum pH at 7.5 and the enzyme II, with a molecular weight of 300,000, and maximum activity at pH 6.0.Both enzymes were strongly inhibited by saccharo-1,4-lactone, glucaro-δ-lactam, p-chloromercuribenzoate, Hg2+, and N-bromosuccinimide. β-Glucuronidase I was active toward estrogen-3-β-glucuronides and inert toward β-glucuronide conjugates of menthol, estrogen-17β-, estrogen-16α-, androsterone-3α-, testosterone-17β-, cortisol-17α-. β-Glucuronidase II hydrolyzed all of these substrates. β-Glucuronidase I was inhhibited by phenolphthalein and its glucuronide.
- Ogushi, Susumu,Koga, Satoshi,Ito, Kiyoshi,Makino, Yasutaka,Ando, Makoto,Tsuru, Daisuke
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p. 3093 - 3100
(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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- CHEMOSELECTIVITY IN MOLYBDENUM CATALYZED ALCOHOL AND ALDEHYDE OXIDATIONS
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Hydrogen peroxide in the presence of (NH4)6Mo7O24*4H2O and potassium carbonate is a chemoselective method to oxidize secondary alcohols to ketones and to oxidize aldehydes to acids, the latter also accelerated by cerium chloride.
- Trost, Barry M.,Masuyama, Yoshiro
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p. 173 - 176
(2007/10/02)
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- PHOSPHINERHODIUM COMPLEXES AS HOMOGENEOUS CATALYSTS. XVI. STEREOSELECTIVE HYDROGENATION OF CYCLIC KETONES
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Cyclic ketones have been hydrogenated stereoselectively with various phosphinerhodium complexes as catalysts.Systems containing phosphines of high basicity and consequently forming RhIII dihydrides as active species yielded mainly the thermodynamically more stable alcohol isomers.Catalysts prepared from aryl-type phosphines of low basicity and modified with Et3N, which contain RhI monohydrides as active complexes, afforded the less stable alcohol isomers as the major products.The ratio of RhIII and RhI hydrides, which determines the stereoselectivity of the catalysts prepared in situ could be changed by suitable choice of base.
- Toros, Szilard,Kollar, Laszlo,Heil, Balint,Marko, Laszlo
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p. 377 - 384
(2007/10/02)
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- ANDROSTENEDIONE METABOLISM IN EPITHELIAL CELLS DERIVED FROM EARLY-LACTATION HUMAN MILK
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Epithelial cells derived from duct epithelium were cultured from early lactation human milk in medium supplemented with 15percent fetal calf serum, insulin (0.3 u/ml), cortisol 21-sodium succinate (6 μg/ml) and amikacin (50 μg/ml).The capacity of these cells to metabolize androstenedione to estrone, estradiol and C19 metabolites was studied during continuous culture.After extraction of the medium, the products were subjected to phenolic partition and separated by thin-layer and paper chromatography, followed by recrystallization to constant specific activity.The study demonstrated a progressive increase in the formation of estrone and testosterone over the first 24 h in culture, while estradiol formation showed an initial 2-4 h lag, then increased slowly.The C19 compounds identified were androsterone, 5α-androstanedione, epiandrosterone, dihydrotestosterone and etiocholanolone. 5α-Androstanedione and androsterone were the major 5α-reduced metabolites.Since these cells are derived from normal duct epithelium, their metabolic characteristics may be more representative of normal breast tissue than those of tissue removed from patients with pathological breast disorders.
- Perel, E.,Stolee, K. J.,Kharlip, L.,Blackstein, M. E.,Killinger, D. W.
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p. 389 - 400
(2007/10/02)
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- Stereoselective and Regioselective Reduction of Steroid Ketones by Potassium Tri(R,S)-s-butyl)borohydride
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Potassium tri(R,S-s-butyl)borohydride reduces 3-oxo-steroids of the 5α- and 5β-series to the axial alcohol under conditions in which the 17- and 20-ketone groups remain unaffected.
- Goendoes, Gyoergy,Orr, James C.
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p. 1239 - 1240
(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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- ANDROGEN METABOLISM IN MALE AND FEMALE BREAST TISSUE
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Incubation studies have been carried out using normal breast tissue and breast tissue from patients with gynecomastia, mammary dysplasia and breast carcinoma to determine the pattern of androstenedione metabolism.All tissues formed estrone (E1) and testosterone (T) in all incubations.Estradiol (E2) was isolated in incubations of tissue from 1 of 6 patients with mammary dysplasia, 5 of 6 patients with gynecomastia and in all incubations with normal and carcinoma tissue.Estrone formation was lowest in mammary dysplasia and gynecomastia, and higher in apparently normal breast tissue.The greatest E1 formation was found in incubations with breast carcinoma tissue, although there was considerable variation within this tissue group.Estradiol formation was low in all tissues, with the highest conversion rates in carcinoma tissue.Testosterone formation in carcinoma tissue was greater than in mammary dysplasia or gynecomastia, but similar to apparently normal tissue.These results indicate that breast tissue from different pathological states varies in its capacity to aromatize androstenedione (A) to estrogenic products and to convert it to other androgens.They have also shown that the pattern of metabolism is distinctive for the nature of the pathological abnormality.
- Perel, E.,Davis, S.,Killinger, D. W.
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p. 345 - 352
(2007/10/02)
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- Activation of Reducing Agents. Sodium Hydride Containing Complex Reducing Agents. 13. Selective Heterogeneous Hydrogenation of Polyfunctional Substrates over Nic
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Preparative-scale heterogeneous hydrogenation over Nic at room temperature and 1 atm are described.It is shown that these catalysts allow the selective hydrogenation of carbon-carbon double bonds in the presence of oxo groups without side reactions.Alkynes and functional alkynes are selectively hydrogenated to the corresponding cis alkenes in high yields.Carbonyl group hydrogenations were also performed in high yields.Selective hydrogenation properties of Nic were exemplified in the steroid series.Finally, it was demonstrated that this new catalyst-preparation concept is not limited to nickel and also applies to the preparation of cobalt and palladium catalysts.
- Gallois, Philippe,Brunet, Jean-Jaques,Caubere, Paul
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p. 1946 - 1950
(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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- CONJUGATION OF ANDROGENS AND ESTROGENS BY HUMAN BREAST TUMORS IN VITRO
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The metabolism of 3H-androstenedione (Δ4-A) and 3H-estriol (E3) was studied in 12 human breast tumors.Part of each tumor was analyzed for estrogen receptor content.Aliquots of tumor homogenates were incubated for 2 hr separately with 3H-Δ4-A and 3H-E3 in the presence of appropriate cofactors.No distinct differences emerged in the profiles of the unconjugated metabolites of 3H-Δ4-A, the major compounds in the approximate order of descendence being androsterone, androstanedione, testosterone, 5α-androstane-3α,17β-diol, epiandrosterone, and dihydrotestosterone.One tumor homogenate from an infiltrating lobular carcinoma converted 3H-Δ4-A to glucosiduronate metabolites (11percent), of which androsterone, 6.4percent; testosterone, 1.6percent; and androstanediol, 0.6percent predominated.The homogenate of this tumor and two other tumors converted 3H-E3 to 3H-E3-3S.Conversions of E3 to E3-3S in the other tumor homogenates were less than 0.6percent.No correlation between receptor content and the capability of the tumor to conjugate Δ4-A or E3 evolved.However, correlations between steroid hormone metabolism and tumor histopathology may exist.
- Raju, Uma,Blaustein, Ancel,Levitz, Mortimer
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p. 685 - 696
(2007/10/02)
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- Photo-induced Transformations. Part 44. Formation of Lactams in the Photolysis of Some Steroidal Acetylhydrazones in the Presence of Oxygen
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Irradiation of 3α-acetoxy-5α-androstan-17-one acetylhydrazone (3) or 3β-acetoxyandrost-5-en-17-one acetylhydrazone (5) in dioxan in the presence of oxygen afforded 17-oxo-17a-aza-D-homosteroid and its 13α-isomer , while when oxygen was excluded none of these lactams were formed under otherwise similar conditions. 5α-Cholestan-6-one acetylhydrazone (20) under similar conditions also afforded very low yields of 6-aza-D-homo-5α-cholestan-7-one (21) and 7-aza-B-homo-5α-cholestan-6-one (22) upon photolysis.In contrast with the acetylhydrazones, the corresponding hydrazone (2), upon photolysis in dioxan without the exclusion of oxygen, afforded the corresponding azine (13) without any accompanying lactams .There is a distinct difference in behaviour between the hydrazones and the N-acetyl derivatives towards oxygen under irradiation.Although as yet no definite conclusion can be drawn on the mechanism of lactam formation, some plausible paths are discussed.
- Suginome, Hiroshi,Uchida, Tsutomu
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p. 1356 - 1364
(2007/10/02)
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- Synthesis of new steroid haptens for radioimmunoassay. III. 15beta Carboxyethylmercaptosteroid bovine serum albumin conjugates. Specific antisera for radioimmunoassay.
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The synthesis of 15β carboxyethylmercapto 5α dihydrotestosterone, 15β carboxyethylmercapto 5α androstane 3β, 17β diol and 15β carboxyethylmercapto 5α androstane 3α, 17β diol and the preparation of their bovine serum albumin (BSA) conjugates are described.
- Rao,Khan,Moore Jr.
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p. 171 - 184
(2007/10/10)
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- Novel N-nitroso compounds, compositions containing such compounds, processes for their preparation and methods of treatment therewith, and novel intermediates
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This invention relates to novel N-halogenoalkyl-N-nitroso carbamates and N 4 halogenalkyl-N 4 -nitroso allophanates of steroid compounds, having an anti-tumor activity, and to the preparation thereof. The invention is also concerned with pharmaceutical compositions containing the said compounds, and methods of treatment therewith.
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