571-31-3Relevant academic research and scientific papers
Unified Total Synthesis of Five Bufadienolides
Hagiwara, Koichi,Inoue, Masayuki,Itoh, Hiroaki,Shimizu, Shinsuke
, (2020/11/13)
We report a unified total synthesis of five bufadienolides: bufalin (1), bufogenin B (2), bufotalin (3), vulgarobufotoxin (4), and 3-(N-succinyl argininyl) bufotalin (5). After the steroidal ABCD ring 8 was produced, the D ring was cross-coupled with a 2-pyrone moiety and stereoselectively epoxidized to generate 6. TMSOTf promoted a stereospecific 1,2-hydride shift from 6 to establish the β-oriented 2-pyrone of 19. Functional group manipulations from 19 furnished 1-5, which potently inhibited cancer cell growth.
Catalytic removal of tert-butyldimethylsilyl (TBS) ether by PVP-I
Ke, Yanxiong,Lu, Guangying,Ren, Jiangmeng,Wang, Di,Zeng, Bu-Bing
, (2019/09/06)
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.
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
-
Paragraph 0022; 0041; 0042; 0043, (2017/02/17)
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.
Characterization of rabbit aldose reductase-like protein with 3β-hydroxysteroid dehydrogenase activity
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)
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.
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
Chen, Jian-Xin,Daeuble, John F.,Stryker, Jeffrey M.
, p. 2789 - 2798 (2007/10/03)
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.
Heterogeneous Catalysis in Carbonyl Regeneration from 1,3-Dithiolanes and 1,3-Dithianes by Zirconium Sulfophenyl Phosphonate
Curini, Massimo,Marcotullio, Maria Carla,Pisani, Emanuela,Rosati, Ornelio,Costantino, Umberto
, p. 769 - 770 (2007/10/03)
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.
Reductive dehalogenation of α-haloketones promoted by hydroiodic acid and without solvent
Penso,Mottadelli,Albanese
, p. 1385 - 1391 (2007/10/02)
Several α-haloketones have been transformed into the corresponding ketones by reaction with aqueous 57% HI, without solvent. The products are obtained in nearly quantitative yields and with high purity (>99%) even in the case of sterically hindered starting materials.
16-substituted androstanes and 16-substituted androstenes
-
, (2008/06/13)
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.
Homoandrostan-17-one and homoandrosten-17-ones
-
, (2008/06/13)
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.
A New Procedure for Dethioacetalization via Equilibrium Exchange with Aqueous Acetone, Paraformaldehyde and Amberlyst 15 as Acidic Catalyst
Ballini, Roberto,Petrini, Marino
, p. 336 - 337 (2007/10/02)
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.
