566-65-4Relevant academic research and scientific papers
Pd nanoparticles as catalysts for green and sustainable oxidation of functionalized alcohols in aqueous media
Mifsud, Maria,Parkhomenko, Ksenia V.,Arends, Isabel W.C.E.,Sheldon, Roger A.
, p. 1040 - 1044 (2010)
The previously described catalyst system for the aerobic oxidation of alcohols, comprising palladium(II) acetate in combination with neocuproine in a 1:1 mixture of water and a water-miscible cosolvent such as ethylene carbonate or dimethylsulfoxide, was shown to involve palladium nanoparticles as the active catalyst. The latter are formed in situ or can be preformed by reduction of the palladium-neocuproine complex with hydrogen and they are stabilized by both the neocuproine ligand and the cosolvent. This catalyst system was successfully used for the selective aerobic oxidation of the steroidal secondary alcohols, nandrolone and 5α-pregnan-3α-ol-20-one, to the corresponding ketones.
Hydrogenation reaction method
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Paragraph 0034; 0181-0184, (2020/05/14)
The invention relates to a hydrogenation reaction method, and belongs to the technical field of organic synthesis. The hydrogenation reaction method provided by the invention comprises the following steps: carrying out a hydrogen transfer reaction on a hydrogen acceptor compound, pinacol borane and a catalyst in a solvent in the presence of proton hydrogen, so that the hydrogen acceptor compound is subjected to a hydrogenation reaction; the catalyst is one or more than two of a palladium catalyst, an iridium catalyst and a rhodium catalyst; the hydrogen acceptor compound comprises one or morethan two functional groups of carbon-carbon double bonds, carbon-carbon triple bonds, carbon-oxygen double bonds, carbon-nitrogen double bonds, nitrogen-nitrogen double bonds, nitryl, carbon-nitrogentriple bonds and epoxy. The method is mild in reaction condition, easy to operate, high in yield, short in reaction time, wide in substrate application range, suitable for carbon-carbon double bonds,carbon-carbon triple bonds, carbon-oxygen double bonds, carbon-nitrogen double bonds, nitrogen-nitrogen double bonds, nitryl, carbon-nitrogen triple bonds and epoxy functional groups, good in selectivity and high in reaction specificity.
Generalized Chemoselective Transfer Hydrogenation/Hydrodeuteration
Wang, Yong,Cao, Xinyi,Zhao, Leyao,Pi, Chao,Ji, Jingfei,Cui, Xiuling,Wu, Yangjie
supporting information, p. 4119 - 4129 (2020/08/10)
A generalized, simple and efficient transfer hydrogenation of unsaturated bonds has been developed using HBPin and various proton reagents as hydrogen sources. The substrates, including alkenes, alkynes, aromatic heterocycles, aldehydes, ketones, imines, azo, nitro, epoxy and nitrile compounds, are all applied to this catalytic system. Various groups, which cannot survive under the Pd/C/H2 combination, are tolerated. The activity of the reactants was studied and the trends are as follows: styrene'diphenylmethanimine'benzaldehyde'azobenzene'nitrobenzene'quinoline'acetophenone'benzonitrile. Substrates bearing two or more different unsaturated bonds were also investigated and transfer hydrogenation occurred with excellent chemoselectivity. Nano-palladium catalyst in situ generated from Pd(OAc)2 and HBPin extremely improved the TH efficiency. Furthermore, chemoselective anti-Markovnikov hydrodeuteration of terminal aromatic olefins was achieved using D2O and HBPin via in situ HD generation and discrimination. (Figure presented.).
NEUROSTEROID COMPOUNDS AND METHODS FOR THEIR PREPARATION AND USE IN TREATING CENTRAL NERVOUS SYSTEM DISORDERS
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, (2019/11/12)
Described herein is the chemical structure of neurosteroid derivative compounds, methods of synthesizing the derivatives, and their uses in treating disorders, including those of the central nervous system. These compounds are readily synthesized and have improved pharmaceutical properties, including water solubility, compared to known neurosteroids.
COMPOSITIONS AND METHODS FOR TREATING CNS DISORDERS
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, (2016/05/24)
Described herein are neuroactive steroids of the Formula (I): or a pharmaceutically acceptable salt thereof; wherein (II), A, R1, R2, R3a, R4a, R4b, R5, R7a, and R7b are as defined herein. Such compounds are envisioned, in certain embodiments, to behave as GABA modulators. The present invention also provides pharmaceutical compositions comprising a compound of the present invention and methods of use and treatment, e.g., such for inducing sedation and/or anesthesia.
Characterization of hamster NAD+-dependent 3(17)β-hydroxysteroid dehydrogenase belonging to the aldo-keto reductase 1C subfamily
Endo, Satoshi,Noda, Misato,Ikari, Akira,Tatematsu, Kenjiro,El-Kabbani, Ossama,Hara, Akira,Kitade, Yukio,Matsunaga, Toshiyuki
, p. 425 - 434 (2015/11/27)
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.
Tetrabutylammonium prolinate-based ionic liquids: A combined asymmetric catalysis, antimicrobial toxicity and biodegradation assessment
Ferlin, Nadege,Courty, Matthieu,Van Nhien, Albert Nguyen,Gatard, Sylvain,Pour, Milan,Quilty, Brid,Ghavre, Mukund,Haiss, Annette,Kuemmerer, Klaus,Gathergood, Nicholas,Bouquillon, Sandrine
, p. 26241 - 26251 (2013/12/04)
Chiral ionic liquids (CILs) tetrabutylammonium-(S)-prolinate, tetrabutylammonium-(R)-prolinate and tetrabutylammonium trans-4-hydroxy-(S)- prolinate were investigated as chiral additives in the Pd-catalyzed enantioselective hydrogenation of α,β-unsaturated ketones. These CILs were easily prepared in one step from the aminoacid and tetrabutylammonium hydroxide and characterized (NMR, IR, optical rotation, elemental analysis, DSC, viscosity, decomposition temperature). The research strategy was to assess the antimicrobial toxicity (>20 strains) and biodegradability (OECD 301D) of the CILs at the same time as undertaking the asymmetric catalysis study. The Pd-catalyzed enantioselective hydrogenation of the carbon-carbon double bond of α,β-unsaturated ketones under mild conditions (room temperature, 1 atm of H2) in different solvents with CILs present. The best results were obtained in i-PrOH after 18 hours of reaction with a i-PrOH/IL ratio of 5. While all three CILs have low antimicrobial toxicity to a wide range of bacteria and fungi, tetrabutylammonium-(S)-prolinate, tetrabutylammonium-(R)-prolinate and tetrabutylammonium trans-4-hydroxy-(S)-prolinate did not pass the Closed Bottle biodegradation test.
Biotransformation of testosterone and progesterone by Penicillium digitatum MRC 500787
Yildirim, Kudret,Gulsan, Fatih,Kupcu, Ilknur
experimental part, p. 675 - 683 (2011/08/03)
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.
Aspects of the progesterone response in Hortaea werneckii: Steroid detoxification, protein induction and remodelling of the cell wall
Krizancic Bombek, Lidija,Lapornik, Ajda,Ukmar, Marjeta,Matis, Maja,Cresnar, Bronislava,Katalinic, Jasna Peter,Zakelj-Mavric, Marija
experimental part, p. 1465 - 1474 (2009/04/06)
Progesterone in sublethal concentrations temporarily inhibits growth of Hortaea werneckii. This study investigates some of the compensatory mechanisms which are activated in the presence of progesterone and are most probably contributing to escape from growth inhibition. These mechanisms lead on the one hand to progesterone biotransformation/detoxification but, on the other, are suggested to increase the resistance of H. werneckii to the steroid. Biotransformation can detoxify progesterone efficiently in the early logarithmic phase, with mostly inducible steroid transforming enzymes, while progesterone biotransformation/detoxification in the late logarithmic and stationary phases of growth is not very efficient. The relative contribution of constitutive steroid transforming enzymes to progesterone biotransformation is increased in these latter phases of growth. In the presence of progesterone, activation of the cell wall integrity pathway is suggested by the overexpression of Pck2 which was detected in the stationary as well as the logarithmic phase of growth of the yeast. Progesterone treated H. werneckii cells were found to be more resistant to cell lysis than mock treated cells, indicating for the first time changes in the yeast cell wall as a result of treatment with progesterone.
Δ5-3β-hydroxysteroid dehydrogenase (3βHSD) from Digitalis lanata. Heterologous expression and characterisation of the recombinant enzyme
Herl, Vanessa,Frankenstein, Joerdis,Meitinger, Nadine,Mueller-Uri, Frieder,Kreis, Wolfgang
, p. 704 - 710 (2008/03/12)
During the biosynthesis of cardiac glycosides, Δ5-3β- hydroxysteroid dehydrogenase (3βHSD, EC 1.1.1.51) converts pregnenolone (5-pregnen-3β-ol-20-one) to isoprogesterone (5-pregnene-3,20-dione). A 3βHSD gene was isolated from leaves of Digitalis lanata. It consisted of 870 nucleotides containing a 90 nucleotide long intron. A full-length cDNA clone that encodes 3βHSD was isolated by RT-PCR from the same source. A Sph I/Kpn I 3βHSD cDNA was cloned into the pQE30 vector and then transferred into E. coli strain M15[pREP4]. 3βHSD cDNA was functionally expressed as a His-tagged fusion protein (pQ3βHSD) composed of 273 amino acids (calculated molecular mass 28,561 Da). PQ3βHSD was purified by metal chelate affinity chromatography on Ni-NTA. Pregnenolone and other 3β-hydroxypregnanes but not cholesterol were 3β-oxidised by pQ3βHSD when NAD was used as the co-substrate. Testosterone (4-androsten-17β-ol-3-one) was converted to 4-androstene-3,17-dione indicating that the pQ3βHSD has also 17β-dehydrogenase activity. pQ3βHSD was able to reduce 3-keto steroids to their corresponding 3β-hydroxy derivatives when NADH was used as the co-substrate. For comparison, 3βHSD genes were isolated and sequenced from another 6 species of the genus Digitalis. Gene structure and the deduced 3βHSD proteins share a high degree of similarity. Georg Thieme Verlag KG Stuttgart.
