- Structural analogs of 1alpha,25-dihydroxycholecalciferol: preparation and biological assay of 1alpha-hydroxypregnacalciferol.
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The synthesis of 1alpha-hydroxypregnacalciferol, a side chain analog of 1alpha,25-dihydroxycholecalciferol (1alpha,25-dihydroxyvitamin D3), is described. Pregnenolone acetate was converted in five steps to 5-pregnen-1alpha,3beta-diol. Conversion of the diol to pregna-5,7-diene-1alpha,3beta diol diacetate followed by ultraviolet irradiation gave the corresponding previtamin derivative. Thermal isomerization, hydrolysis and chromatography then furnished the desired analog, 1alpha-hydroxypregnacalciferol. The compound was tested in vivo for its effect on intestinal calcium transport, serum calcium and phosphate levels and bone calcification, and in vitro for its effect on bone resorption. When given to intact rats, either as a single dose or in repeated daily doses, the analog even at high dose levels, exhibited no biological activity. The compound stimulated bone resorption in vitro, but only at high concentrations.
- Lam,Schnoes,DeLuca,Reeve,Stern
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- 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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Page/Page column 51; 58
(2020/02/23)
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- Positive Modulators of the N-Methyl- d -aspartate Receptor: Structure-Activity Relationship Study of Steroidal 3-Hemiesters
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Here, we report the synthesis of pregn-5-ene and androst-5-ene dicarboxylic acid esters and explore the structure-activity relationship (SAR) for their modulation of N-methyl-d-aspartate receptors (NMDARs). All compounds were positive modulators of recombinant GluN1/GluN2B receptors (EC50 varying from 1.8 to 151.4 μM and Emax varying from 48% to 452%). Moreover, 10 compounds were found to be more potent GluN1/GluN2B receptor modulators than endogenous pregnenolone sulfate (EC50 = 21.7 μM). The SAR study revealed a relationship between the length of the residues at carbon C-3 of the steroid molecule and the positive modulatory effect at GluN1/GluN2B receptors for various D-ring modifications. A selected compound, 20-oxo-pregnenolone hemiadipate, potentiated native NMDARs to a similar extent as GluN1/GluN2A-D receptors and inhibited AMPARs and GABAAR responses. These results provide a unique opportunity for the development of new steroid based drugs with potential use in the treatment of neuropsychiatric disorders involving hypofunction of NMDARs.
- Krausova, Barbora,Slavikova, Barbora,Nekardova, Michaela,Hubalkova, Pavla,Vyklicky, Vojtech,Chodounska, Hana,Vyklicky, Ladislav,Kudova, Eva
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p. 4505 - 4516
(2018/05/15)
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- Synthesis of Triaromatic Steroid Hydrocarbons Methylated at Position 2, 3 or 6: Molecular Fossils of Yet Unknown Biological Origin.
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C21-29 triaromatic steroid hydrocarbons bearing a methyl group at unusual positions 2, 3 or 6 have been synthesized from pregnenolone, cholesterol or stigmasterol via stera-3,5-dienes.Their occurence in various sedimentary rocks and petroleums suggests the presence of yet unknown biological precursors.
- Lichtfouse, Eric,Albrecht, Pierre
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p. 1731 - 1744
(2007/10/02)
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- OCCURRENCE OF 2-METHYL-, 3-METHYL- AND 6-METHYLTRIAROMATIC STEROID HYDROCARBONS IN GEOLOGICAL SAMPLES.
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Triaromatic steroid hydrocarbons bearing a methyl substituent at position 2, 3, or 6 have been identified in marine sediments and petroleums from the Paris basin by comparison with C21 (1, 2, 3), C27 (4) and C29 (5) synthetic standards.Due to their formation with depth they are useful for maturity studies.
- Lichtfouse, E.,Riolo, J.,Albrecht, P.
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p. 3937 - 3940
(2007/10/02)
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