Mass spectrometry and stability of t-butyldimethylsilylethers of some estrogens and androstanes.

abstract：:The first convenient chemical synthesis of 7alpha-hydroxyandrost-4-ene-3,17-dione is reported. Androsta-4,6-diene3, 17-dione was converted into its 6alpha, 7alpha-epoxy-derivative; reduction of the epoxide with aluminum amalgam gave 7alpha-hydroxyandrost-4-ene-3,17-dione. This reducing agent is more efficient than chr...

journal_title：Steroids

authors： Hossain AM,Kirk DN,Mitra G

更新日期：1976-05-01 00:00:00

abstract：:Novel C6-piperazine substituted purine nucleoside analogues (2-9) bearing a modified pyranose-like D ring of the 4-azasteroid moiety were efficiently synthesized through nucleophilic substitution at C6 position of the steroid-nucleoside precursors (1) with versatile piperazines. All newly-synthesized compounds were ev...

journal_title：Steroids

authors： Huang LH,Xu HD,Yang ZY,Zheng YF,Liu HM

更新日期：2014-04-01 00:00:00

abstract：:The synthesis of delta 7,9(11)-lanostadiene derivatives functionalized at C(32) starting from 3 beta-acetoxy-7 alpha,32-epoxylanostan-11-one has been presented. The delta 7,9(11) moiety was efficiently introduced in three steps in 71% yield by the regioselective abstraction of allylic 8 beta hydrogen. The formyl group...

journal_title：Steroids

authors： Solaja BA,Dermanović M,Lim DM,Paik YK,Tinant B,Declerq JP

更新日期：1997-11-01 00:00:00

abstract：:A series of clickable bile acid-nucleosides conjugates linked directly or via amino acid linker were synthesized, and characterized by spectroscopic techniques such as 1H NMR, 13C NMR, FT-IR, HRMS and HPLC. The synthesized compounds 6a-p were screened for their in vitro anticancer property against a panel of three can...

journal_title：Steroids

authors： Agarwal DS,Siva Krishna V,Sriram D,Yogeeswari P,Sakhuja R

更新日期：2018-11-01 00:00:00

abstract：:C17-20Lyase and 21-hydroxylase activities were measured during late gestation in the rhesus monkey (Macaca mulatta) fetal adrenal. Activities were assessed in 10,000 x g supernatants with 17-hydroxyprogesterone and NADPH as substrates. Although conversion of [14C]17-hydroxyprogesterone to [14C]androstenedione was note...

journal_title：Steroids

authors： Sholl SA

更新日期：1981-08-01 00:00:00

abstract：:Effective syntheses of endo- and exocyclic alpha,beta-unsaturated ketones as CC dipolarophiles were carried out in the 13alpha-estrone series. The 1,3-dipolar cycloadditions of 15,16alpha,beta-unsaturated ketones of 13alpha-estrone 3-methyl and 3-benzyl ether with nitrilimines stereoselectively furnished two regioisom...

journal_title：Steroids

authors： Mernyák E,Kozma E,Hetényi A,Márk L,Schneider G,Wölfling J

更新日期：2009-06-01 00:00:00

abstract：:The giant freshwater prawn, Macrobrachium rosenbergii, is important to many Asian countries due to its high economic value as an aquaculture product. With demand increasing, there is requirement for a better understanding of the biosynthetic components that regulate its growth and reproduction, including steroids, in ...

journal_title：Steroids

authors： Thongbuakaew T,Siangcham T,Suwansa-ard S,Elizur A,Cummins SF,Sobhon P,Sretarugsa P

更新日期：2016-03-01 00:00:00

abstract：:Estradiol benzoate (EB) has been one of the most widely used estrogenic agents in animal husbandry, as a way of exogenously introducing the natural hormone estradiol-17β into the animal organism. Estradiol was previously employed to induce anabolic effects or reproductive improvements in cattle. However, the employmen...

journal_title：Steroids

authors： Regal P,Nebot C,Díaz-Bao M,Barreiro R,Cepeda A,Fente C

更新日期：2011-03-01 00:00:00

abstract：:Estradiol (E2), progesterone (P4), and oxytocin (OT) are important for the initiation of luteolysis in ruminants but the mechanisms involved are still poorly understood. The objective of this study was to determine if duration of exposure of bovine endometrial epithelial cells to P4 affected the response of the cells ...

journal_title：Steroids

authors： Kombé A,Sirois J,Goff AK

更新日期：2003-09-01 00:00:00

abstract：:26,26,26,27,27,27-Hexafluo-1,25(OH)2 vitamin D3, the hexafluorinated analog of 1,25(OH)2 vitamin D3, has been reported to be several times more potent than the parent compound regarding some vitamin D actions. The reason for enhanced biologic activity in the kidneys and small intestine appears to be related to F6-1,25...

journal_title：Steroids

authors： Komuro S,Kanamaru H,Nakatsuka I,Yoshitake A

更新日期：1998-10-01 00:00:00

abstract：:A cytochrome P450-deficient mutant of the pathogenic fungus, Candida albicans, which accumulates exclusively 14 alpha-methylsterols in place of the normal end product sterol, ergosterol, was examined for alterations in membrane fluidity by electron paramagnetic resonance. The results using four nitroxyl spin labels in...

journal_title：Steroids

authors： Lees ND,Kleinhans FW,Broughton MC,Pennington DE,Ricker VA,Bard M

更新日期：1989-03-01 00:00:00

abstract：:Dehydroepiandrosterone (DHEA) is a multifunctional steroid with a broad range of biological effects in humans and animals. DHEA can be converted to multiple oxygenated metabolites in the brain and peripheral tissues. The mechanisms by which DHEA exerts its effects are not well understood. However, evidence that the ef...

journal_title：Steroids

authors： El Kihel L

更新日期：2012-01-01 00:00:00

abstract：:Brassinosteroids (BRs) are steroid hormones regulating various aspects of plant metabolism, including growth, development and stress responses. However, little is known about the mechanism of their impact on antioxidant systems and phospholipid turnover. Using tobacco plants overexpressing H+/Ca2+vacuolar Arabidopsis ...

journal_title：Steroids

authors： Kretynin SV,Kolesnikov YS,Derevyanchuk MV,Kalachova TA,Blume YB,Khripach VA,Kravets VS

更新日期：2019-07-08 00:00:00

abstract：:Contrary to the long-held postulate of steroid-hormone binding globulin action, these protein carriers of steroids are major players in steroid actions in the body. This manuscript will focus on our work with sex hormone binding globulin (SHBG) and corticosteroid binding globulin (CBG) and demonstrate how they are act...

journal_title：Steroids

authors： Caldwell JD,Jirikowski GF

更新日期：2014-03-01 00:00:00

abstract：:Steroid research at Lederle was initiated in 1946 and continued until about 1971. The areas of research interest involved primarily a study of delta 5,7-steroids, provitamin D3 variants, dehydroepiandrosterone variants, steroidal ketals, corticoids, and steroid conjugates. One of the principal goals was to develop nov...

journal_title：Steroids

authors： Bernstein S

更新日期：1992-08-01 00:00:00

abstract：:A phytochemical study of Physalis pubescens L. afforded twelve compounds, including six new withanolides (1, 4, and 6i-9), four new withanolide glucosides (2, 3, 5, and 6), and two known withanolides (10 and 11). Their structures were established via extensive spectroscopic analysis. The absolute configuration of 3 wa...

journal_title：Steroids

authors： Xia G,Li Y,Sun J,Wang L,Tang X,Lin B,Kang N,Huang J,Chen L,Qiu F

更新日期：2016-11-01 00:00:00

abstract：:The luteinizing hormone (LH) surge initiates a cascade of proteolytic events that control ovulation. One of the genes induced by LH is the progesterone receptor (PR). Because mice with a mutant PR gene (PRKO) fail to ovulate and are infertile, we have used them as a model in which to determine PR target genes that mig...

journal_title：Steroids

authors： Robker RL,Russell DL,Yoshioka S,Sharma SC,Lydon JP,O'Malley BW,Espey LL,Richards JS

更新日期：2000-10-01 00:00:00

abstract：BACKGROUND:Once a septic condition is progressing, administration of steroids in the pro-inflammatory phase of septic shock ought to yield maximal effect on the subsequent, devastating inflammatory response. Recently, a retrospective study showed that early initiation of corticosteroid therapy improved survival in sept...

journal_title：Steroids

authors： Söderberg E,Lipcsey M,Sjölin J,Larsson A,Eriksson MB

更新日期：2012-09-01 00:00:00

abstract：:Until recently, the idea that estradiol could affect cellular processes independent of nuclear estrogen receptors was often dismissed as artifact. This in spite of a large number of carefully controlled studies performed both within and outside the nervous system demonstrating estrogens regulate various intracellular ...

journal_title：Steroids

authors： Boulware MI,Mermelstein PG

更新日期：2009-07-01 00:00:00

abstract：:Seventeen cholesteryl alkyl ethers were synthesized through alcoholysis of cholesterol p-toluenesulfonate. This method was found superior to the etherification of sodium or potassium cholesterylate with alkyl halides or methanesulfonates, especially for the preparation of long-chain unsaturated aklyl ethers of [7(m)-3...

journal_title：Steroids

authors： Halperin G,Gatt S

更新日期：1980-01-01 00:00:00

abstract：:15alpha-Hydroxydehydroisoandrosterone and 15alpha-hydroxypregnenolone were isolated from hydrolyzed extracts of human late pregnancy urine and identified by means of the isotope dilution technique. In two separate determinations the excretion rate of 15alpha-hydroxydehydroisoandrosterone was found to be 1.7 and 3.2 mi...

journal_title：Steroids

authors： Stanczyk FZ,Stern M,Solomon S

更新日期：1978-05-01 00:00:00

abstract：:Steroid derivatives V, VI, VII and VIII reacted with Lawesson's reagent (LR) to produce spiro-oxazaphosphole-4',17-androstene derivative XI, diazaphospholoandrostane XIV and the thionated derivatives XVI and XVII, respectively. The structures of the new compounds were confirmed by analytical and spectroscopic evidence...

journal_title：Steroids

authors： Mohamed NR,Elmegeed GA,Abd-ElMalek HA,Younis M

更新日期：2005-03-01 00:00:00

abstract：:Corticosteroids were used normally as anti-inflammatory drugs. However, in some area certain corticosteroids might be illegally used as growth promoting agent in feed, and as prohibited doping substances in game and sport for human or/and animal performance-enhancing. Synthesized structural similar corticosteroids wer...

journal_title：Steroids

authors： Chen SY,Fang M,Lin YT,Tsai CF,Cheng HF,Wang DY

更新日期：2021-01-01 00:00:00

abstract：:11 beta-hydroxysteroid dehydrogenase (11 beta-HSD), the enzyme that catalyzes the conversion of biologically active glucocorticoids to their inactive metabolites, was shown to be located exclusively in Leydig cells of the rat testis, and its appearance was associated with the developmental rise in testosterone. Thus, ...

journal_title：Steroids

authors： Nacharaju VL,Muneyyirci-Delale O,Khan N

更新日期：1997-03-01 00:00:00

abstract：:Homogenates from human myometrium with an added NADPH regenerating system and ATP were incubated with 4-(14)C progesterone. Six metabolites were identified: 5alpha-pregnane-3, 20-dione, 5beta-pregnane-3, 20-dione, 3alpha-hydroxy-4-pregnen-20-one, 3beta hydroxy-4-pregnen-20-one. 20alpha-hydroxy-4-pregnen-3-one and 20be...

journal_title：Steroids

authors： Junkermann H,Runnebaum B,Lisboa BP

更新日期：1977-07-01 00:00:00

abstract：BACKGROUND:Polycystic ovary syndrome (PCOS) is mainly defined by hyperandrogenemia, from ovarian and adrenal origin, and is characterized by insulin resistance (IR). Studies found that raising in vivo non-esterified fatty acid (NEFA) levels, which induces lipotoxicity, increases androgen levels and IR. The aim of this ...

journal_title：Steroids

authors： Bellanger S,Battista MC,Fink GD,Baillargeon JP

更新日期：2012-03-10 00:00:00

abstract：:Radioimmunoassay (RIA) for testosterone (T) in unchromatographed plasma extracts from ATD-treated rats gave spuriously high values for T. Cross-reaction and chromatographic studies subsequently showed that ATD and, to a much greater extent, its metabolite(s) were responsible for this overestimation. Celite column chro...

journal_title：Steroids

authors： Donaldson MD,Forest MG

更新日期：1980-12-01 00:00:00

abstract：:The configurations at C-24 of 24-alkylsterols of six samples of Clerodendrum species (Verbenaceae) - the aerial parts of C. fragrans, C. inerme, C. infortunatum, C. scandens, and C. siphonanthus, and the seeds of C. infortunatum - were examined by NMR. All samples contained 24 beta-ethylsterols possessing a delta 25-b...

journal_title：Steroids

authors： Akihisa T,Matsubara Y,Ghosh P,Thakur S,Tamura T,Matsumoto T

更新日期：1989-03-01 00:00:00

abstract：:The binding activity of four vitamin D metabolites and/or analogs for the intestinal 1,25-dihydroxyvitamin D3 receptor was evaluated after incubation at 25 degrees C for 1 h or at 0-4 degrees C for 18 h. The incubation conditions, which had no effect on the binding of 1,25-dihydroxyvitamin D3, had a dramatic effect on...

journal_title：Steroids

authors： Link RP,DeLuca HF

更新日期：1988-05-01 00:00:00

abstract：:The abilities of a variety of estrogens and antiestrogens to stimulate DNA synthesis in the prepuberal rat uterus were compared. One microgram of each compound was administered in vivo via a single intraperitoneal injection. DNA synthesis was assayed in vitro in isolated nuclei 24 h later. The relative mitogenicities ...

journal_title：Steroids

authors： Stack G,Korach K,Gorski J

更新日期：1989-08-01 00:00:00