- 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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- 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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- 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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- 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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- 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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- 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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- 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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- 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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- 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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- 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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- REDUCTIONS MICROBIOLOGIQUES STEREOSELECTIVES DES Δ-4 CETO-3 STEROIDES
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In anaerobic conditions the reduction of Δ-4 3-keto steroids by Clostridium paraputrificum leads either to the 3-keto 5β compounds or to the corresponding 3α-hydroxytetrahydro-5β derivatives.This stereospecific bioconversion of αβ-unsaturated 3-keto steroids is shown to be directed by the substrate concentration.The conversion of Δ-4 cholestenone to coprostanone or coprostanol is not observed.
- Fauve, A.,Kergomard, A.
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p. 899 - 901
(2007/10/02)
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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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- SIDE CHAIN CLEAVAGE OF PROGESTERONE BY ASPERGILLUS AUREOFULGENS
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Aspergillus aureofulgens transformed progesterone (I) into androst-4-en-3,17-dione (II), testosterone acetate (III), testosterone (IV), 5β-androsta-3,17-dione (V) and 5β-androsta-3α-ol-17-one (VI).The side chain cleavage of progesterone proceeded by a pathway similar to non-enzymic Baeyer-Villiger oxidation of ketones to esters.Moreover, the microbial degradation of progesterone was in part accompanied by the stereospecifical reduction of the formed C-19 steroids to the 5β-androstan derivatives (V) and (VI).
- Cattel, L.,Caputo, O.,Viola, F.,Balliano, G.
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p. 843 - 847
(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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