- METHODS OF ACTIVATING MICROGLIAL CELLS
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The present disclosure provides methods of using compositions that inhibit SH2-containing inositol 5'-phosphatases (SHIPs) for activating microglial cells, as well as methods for using such compositions for treatment or ameliorating of neurodegenerative disorders in a subject.
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- HUMAN GHRELIN O-ACYL TRANSFERASE INHIBITORS
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A class of cyanosteroid compounds that efficiently inhibit ghrelin acylation by ghrelin O-acyltransferase. The compounds have a steroid scaffold with α,β-unsaturated ketone in the A ring position such an a-cyanoenone. Exemplary compounds include (5S,8S,9S,10S, 13S,14S)-10,13-dimethyl-3-oxo-4,5,6,7,8,9,10,11,12,13,14,15,16,17- tetradecahydro-3H-cyclopenta[a]phenanthrene-2-carbonitrile.
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Paragraph 0052-0054
(2018/03/09)
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- Androstanes with modified carbon skeletons
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Four sterane hydrocarbons were prepared for comparisonwith fossil organic biomarkers in geological samples from Oman. 17ss-Methylestrane was prepared in six steps (36% overall yield) from estrone methyl ether. Key steps of this sequence were a Wittig olefination and Birch reduction of the A-ring. 17ss-Methylandrostane was obtained in four steps (85% overall yield) from trans-androsterone by four functional group interconverting reactions, including aWittig olefination. 17ss-Methyl-and 2α-methyl-A-nor-5α- androstanes (14 and 15% overall yields, respectively) were also prepared from trans-androsterone. Key steps were the thallium trinitrate mediated ring contractions of A-ring ketones to A-nor-2-carboxylic acids. Defunctionalization in the four syntheses was achieved by catalytic hydrogenation, Huang-Minlon reduction, Barton decarboxylation, and Bu3SnH-mediated reduction of a chloromethyl group, respectively.
- Norden, Sascha,Bender, Matthias,Rullkoetter, Juergen,Christoffers, Jens
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p. 4543 - 4550
(2011/09/16)
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- Novel and efficient synthesis and antifungal evaluation of 2,3-functionalized cholestane and androstane derivatives
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Synthetic modifications of cholesterol and other traditional steroid molecules have become a promising area for the exploration and development of novel antifungal agents, especially with respect to the development of fatty-acid esters of steroids. In addition, 2,3-functionalized steroids are also compounds with potentially interesting biological properties and proper functionalization of 2,3-steroids can lead to the development of efficient syntheses of building blocks for novel fatty-acid esters of steroids. In this Letter, we outline a novel and efficient approach to the synthesis of 2,3-functionalized cholestane and androstane derivatives and present their promising preliminary antifungal activities against a number of fungal species.
- Jursic, Branko S.,Upadhyay, Sunil Kumar,Creech, Clinton C.,Neumann, Donna M.
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supporting information; experimental part
p. 7372 - 7375
(2011/02/23)
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- Photochemical Behavior of Δ4-3-Oxo, Δ5-7-Oxo, and Δ1-3-Oxo Steroids in Concentrated Acid Solution
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Irradiation with UV light of 5α-androst-1-en-3-one (9) in concentrated sulfuric acid leads to 15 and 16; similarly 4a-methyl-4a,5,6,7,8,8a-hexahydronaphthalen-2(1H)-one (10) gives 17 and 18.The formation of the four products is rationalized in terms of a photochemically induced 1,2-alkyl shift to the positively charged positions of the starting carbenium ions.On the other hand, irradiation under the same conditions of 4, 8, 7, and 11 yields, quantitatively, unchanged starting material, while the analogous bicyclic compound Δ1,9-10-methyl-2-octalone (1) has been reported to yield photorearrangement products.The lack of reactivity of 7 and 11 can be explained according to the proposed mechanism for the photorearrangement of 1.In the case of 4 and 8, the presence of the steroid rings C and D prevents the photorearrangement, but the mechanistic explanation of this effect cannot be determined from the present experimental data.
- Lupon, Pilar,Canals, Francesc,Iglesias, Arsenio,Ferrer, Joan C.,Palomer, Albert,et al.
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p. 2193 - 2198
(2007/10/02)
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- 1H NMR Analyses, Shielding Mechanisms, Coupling Constants, and Comformations is Steroids Bearing Halogen, Hydroxy, Oxo Groups, and Double Bonds
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The 1H NMR analyses of 16 5αH-androstanes and one progesterone analogue furnish shifts and coupling constants for the basic steroid skeleton and substituent-induced shifts (SIS) for oxo, hydroxy, and halogen groups as well as for a Δ double bond.It is shown how a single 2D experiment complemented by a NOE difference spectrum can lead to complete assignments even with the most complicated spin systems compirising, e.g., 29 strongly coupled protons within only 1 ppm; the accurancy of information from 2D techniques is evaluated by comparison to some 1D and computer-simulated spectra.On the basis of up to six simultaneously observable couplings, a special approach is used to scan the conformational space of particularly flexible parts.Intermediate conformations between half-chair and twist are obtained with a torsional C14-C15-C16-C17 angle of φ ca. 20 deg for the D ring with a sp2 (17-oxo) carbon and of φ ca. 10 deg with only sp3 carbon atoms; the observed flat profiles, however, allow also for mixtures of different conformations, which is supported by MM2 calculations.For the Δ-3-oxo A ring, a sofa conformation is favored compared to a half-chair geometry.The observed shielding effects of heterosubstituents are partially at variance with the few earlier observations, which were mostly based on polysubstituted compounds.Classical shielding mechanisms were evaluated with the program SHIFT, based on force-field-minimized structures.Steric-induced shielding dominates in the hydrocarbon, leading to upfield shifts increasing with the number of 1,3-diaxial interactions.Linear electric-field effects predict, e.g., the shielding difference between equatorial and axial protons vicinal to C-Hal bonds and the deshielding observed for diaxial C-Hal/C-H bond arrangements.A combination of anisotropy and electric-field effects explains all shifts observed in the ketones with the exception of protons vicinal to C=O; a multilinear regression analysis leads to Δχ1C=O = -36 (-27) and Δχ2C=O = -24 (-21) (10-3 cm3/molecule, old ApSimon values in parentheses); it is, however, demonstrated, that an analysis on the basis of NMR shifts alone leads to broad ranges of parameters.Parallels between 1H and 13C NMR shifts are drawn, particularly at γ and θ positions to C-Hal bonds.
- Schneider, Hans-Joerg,Buchheit, Ulrich,Becker, Norman,Schmidt, Guenter,Siehl, Ulrich
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p. 7027 - 7039
(2007/10/02)
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- Stereochemistry of the Palladium-catalyzed Hydrogenation of 3-Oxo-4-ene Steroids. V. A Kinetic Study in Basic and Acidic Media
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Effects of the β-methyl group at C-10 and some oxygen functions (=O, OH, OAc) at C-11, C-17, and C-20 on the rates of hydrogenation of 3-oxo-4-ene steroids have been studied with palladium catalyst in pyridine or THF/HBr as solvent.In contrast to the hydrogenation in pyridine, the rate in THF/HBr was greatly depressed by the presence of 10β-methyl group.The reactivity of the steroids was enhanced by the oxygen functions, in particular, by 11, 17-dioxo group.The effects of the substituents are discussed from a mechanistic consideration based on the obtained results.
- Nishimura, Shigeo,Momma, Yasuhiro,Kawamura, Hideo,Shiota, Michio
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p. 780 - 783
(2007/10/02)
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- Photorearrangement of 5α-Androst-1-en-3-one in Concentrated Acid Soluti
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U.v. irradiation of the title compound in concentrated sulphuric acid gives mainly 5(10 -> 1)abeo steroids.
- Lupon, Pilar,Ferrer, Joan C.,Piniella, Joan F.,Bonet, Juan-Julio
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p. 718 - 719
(2007/10/02)
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