Synthesis and biological activity of brassinosteroids fluorinated at C-2.

abstract：:Using 1 alpha,2 alpha-oxido-cholesta-5,7-diene-3 beta,25-diol (2) as a starting material, the provitamins of calcitriol with an additional 2 beta-chloro-, 2 beta-fluoro-, and 2 beta-methoxy-substituent (3,4,5) are obtained by transdiaxial opening of the oxirane ring with nucleophiles. An efficient irradiation process ...

journal_title：Steroids

authors： Scheddin D,Mayer H,Schönecker B,Gliesing S,Reichenbächer M

更新日期：1998-12-01 00:00:00

abstract：:During the second half of the luteal phase, the human corpus luteum becomes responsive to regular luteinizing hormone (LH) pulses. These LH pulses stimulate progesterone secretion tonically, and during this tonic stimulation, additional LH-independent progesterone pulses occur, which are particularly pronounced in wom...

journal_title：Steroids

authors： Wuttke W,Theiling K,Hinney B,Pitzel L

更新日期：1998-05-01 00:00:00

abstract：:Testosterone (17 beta -hydroxy-4-androsten-3-one ; T) and dihydrotestosterone (17 beta -hydroxy-5 alpha -androstan-3-one ; DHT) concentrations were determined by radioimmunoassay in different fetal tissues taken from male guinea-pigs. Androgen concentrations were maximal in the components of the Wolffian duct (vas def...

journal_title：Steroids

authors： Rigaudière N

更新日期：1981-08-01 00:00:00

abstract：:Key to the production of biologically active steroids is the enzyme 3 beta-hydroxysteroid dehydrogenase-isomerase. Some controversy has arisen concerning the subcellular distribution of this enzyme within steroidogenic cells. The distribution of 3 beta-hydroxysteroid dehydrogenase-isomerase was assessed in subcellular...

journal_title：Steroids

authors： Perry JE,Ishii-Ohba H,Stalvey JR

更新日期：1991-06-01 00:00:00

abstract：:The kinetics of 11 beta-hydroxysteroid dehydrogenase (11HSD) catalyzing the interconversion of cortisol (F) and cortisone (E) were compared in vitro following incubation of homogenates of human (N = 7) and baboon (N = 2) placenta. In both species, enzyme activity catalyzing the conversion of F to E was associated with...

journal_title：Steroids

authors： Pepe GJ,Albrecht ED

更新日期：1984-09-01 00:00:00

abstract：:An efficient procedure for the chemical synthesis of 3 beta-hydroxy-5 alpha-cholest-8-en-7-one and 3 beta-hydroxy-5 alpha-cholest-8-en-11-one is described. These ketosterols have been shown to have possible significant hypocholesterolemic effects when fed to normal rats at a level of 0.15% in a laboratory chow diet. T...

journal_title：Steroids

authors： Parish EJ,Nanduri VB,Seikel JM,Kohl HH,Nusbaum KE

更新日期：1986-11-01 00:00:00

abstract：OBJECTIVE:To evaluate the role of physiologic levels of androgens and their precursors in the regulation of body composition, energy and substrate metabolism and aerobic capacity in healthy, cycling, premenopausal women. EXPERIMENTAL:We evaluated 30 young (27±1 year) premenopausal, non-obese (23±0.5 kg/m(2)), normally...

journal_title：Steroids

authors： Keller JL,Casson PR,Toth MJ

更新日期：2011-11-01 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：:Ethynylestradiol (EE2) is one of the most potent endocrine disrupting compounds capable to induce estrogenic effects even at trace level concentrations in the aquatic environment. Methods for detecting EE2 in such concentrations are generally based on GC or HPLC coupled to at least one mass spectrometer. Another appro...

journal_title：Steroids

authors： Schneider C,Schöler HF,Schneider RJ

更新日期：2004-04-01 00:00:00

abstract：:13beta-Ethyl-3-methoxy-17beta-ol-8,14-seco-1,3,5(10),8-gonatetraen-14-one (IIIa) was isolated and its participation in the well-known acidic cyclization process was established. ...

journal_title：Steroids

authors： Makk N,Tóth G,Tömörkény E

更新日期：1975-05-01 00:00:00

abstract：:The reaction of 23-oxotigogenin acetate with TMSOTf in THF afforded the corresponding bisnorcholanic lactone in 60% yield. The analogous reactions carried out in dichloromethane or benzene gave the rearranged products--the isomeric spirostanic ketone (10-15%) and bisfuran (40-42%). Similar products were also obtained ...

journal_title：Steroids

authors： Jastrzebska I,Siergiejczyk L,Tomkiel AM,Urbańczyk-Lipkowska Z,Wójcik D,Morzycki JW

更新日期：2009-08-01 00:00:00

abstract：:Biotransformation of danazol (1) (17β-hydroxy-17α-pregna-2,4-dien-20-yno-[2,3-d]-isoxazole) with Cunninghamella blakesleeana yielded three new metabolites 2-4 and a known metabolite 5. These metabolites were identified as 14β,17β-dihydroxy-2-(hydroxymethyl)-17α-pregn-4-en-20-yn-3-one (2), 1α,17β-dihydroxy-17α-pregna-2...

journal_title：Steroids

authors： Baydoun E,Atia-tul-Wahab,Mehmood H,Ahmad MS,Malik R,Smith C,Choudhary MI

更新日期：2016-01-01 00:00:00

abstract：:A virulent culture of Hymenoscyphus fraxineus, the causal agent of ash dieback, was investigated for its production of secondary metabolites in a 70 L batch fermentation. Chemical analysis of the mycelial extract by means of flash chromatography and preparative HPLC led to the isolation of a new ergostane-type steroid...

journal_title：Steroids

authors： Surup F,Halecker S,Nimtz M,Rodrigo S,Schulz B,Steinert M,Stadler M

更新日期：2018-07-01 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：:Through its collaboration with the ETH in Zurich (Ruzicka's group) and later on with the University of Basel (Reichstein's group). Ciba became involved very early in steroid chemistry. The main task of the chemists consisted at that time of the synthesis of natural hormones and their derivatives. Cholesterol served fo...

journal_title：Steroids

authors： Heusler K,Kalvoda J

更新日期：1996-08-01 00:00:00

abstract：:The concentration of testosterone (T) in the peripheral plasma of laboratory mice is extremely variable. This variability is already evident at 20--25 days of age and is not eliminated by brief or chronic exposure to male or female mice, or by isolation. The variation in T levels in plasma samples collected from the s...

journal_title：Steroids

authors： Bartke A,Dalterio S

更新日期：1975-12-01 00:00:00

abstract：:Acrolein, an α, β-unsaturated aldehyde, exists in a wide range of sources. Acrolein can be not only generated from all types of smoke but also produced endogenously from the metabolism by lipid peroxidation. The cellular influence of acrolein is due to its electrophilic character via binding to and depleting cellular ...

journal_title：Steroids

authors： Yeh YH,Chou JC,Weng TC,Lieu FK,Lin JY,Yeh CC,Hu S,Wang PS,Idova G,Wang SW

更新日期：2016-07-01 00:00:00

abstract：:A series of steroidal and nonsteroidal Michael acceptors that represent reaction products for 3 alpha-hydroxysteroid dehydrogenase were synthesized and evaluated as potential enzyme-generated inactivators. Introduction of exocyclic olefins either at C-2 or C-6 produced inhibitors with high affinity for the enzyme (0.0...

journal_title：Steroids

authors： Penning TM,Thronton R,Ricigliano JW

更新日期：1991-08-01 00:00:00

abstract：:Circulation levels of estrone sulfate (E1S) and dehydroepiandrosterone sulfate (DHAS) have been measured in plasma using a radioimmunoassay for estrone and dehydroepiandrosterone following extraction and hydrolysis of the sulfate. The mean +/- SE concentrations of E1S and DHAS in normal men were 458 +/- 25 pg/ml and 1...

journal_title：Steroids

authors： Franz C,Watson D,Longcope C

更新日期：1979-11-01 00:00:00

abstract：:In the present study the possible dual effects of adenosine as substrate and adenosine receptor agonist in rat granulosa cells, cumulus-oocyte complexes, luteal cells and ovarian membranes are discussed. Adenosine is an indispensable compound in cell energy metabolism, as precursor to cofactors, second messenger and n...

journal_title：Steroids

authors： Billig H,Rosberg S,Johanson C,Ahrén K

更新日期：1989-11-01 00:00:00

abstract：:Steroid delta 4-5 alpha- and delta 4-5 beta-reductase activity was determined in 16 human mammary tumors and 8 DMBA-induced rat mammary tumors using a spectrophotometric assay. Steroid delta 4-5 alpha-reductase was present in all tumors investigated while delta 4-5 beta-reductase was detected in only 6 estrogen recept...

journal_title：Steroids

authors： Abul-Hajj YJ

更新日期：1979-01-01 00:00:00

abstract：:The crystal structures of chenodeoxycholic acid (CDCA), ursodeoxycholic acid (7beta isomer of CDCA) and their other two epimers (3beta,7alpha- and 3beta,7beta-isomers) have been resolved. The four isomers were recrystallized from p-xylene. CDCA crystal is hexagonal P6(5) while the crystals of the other three isomers a...

journal_title：Steroids

authors： Alvarez M,Jover A,Carrazana J,Meijide F,Soto VH,Tato JV

更新日期：2007-06-01 00:00:00

abstract：:In this study, we assessed the rate of estradiol degradation via the 17 beta-hydroxysteroid dehydrogenase (HSD) enzyme in breast tumors from postmenopausal women. We initially studied the effects of time, level of enzyme activity, amount of tissue assayed, and substrate concentration on the linearity of conversion of ...

journal_title：Steroids

authors： Leszczynski D,Santner SJ,Feil PD,Santen RJ

更新日期：1988-03-01 00:00:00

abstract：:The palladium-catalyzed coupling of various 17-iodo-delta 16 steroids (17-iodo-androst-16-ene, 17-iodo-4-methyl-4-aza-androst-16-en-3-one, and 17-iodo-4-aza-androst-16-en-3-one) with dialkyl phosphites (dimethyl phosphite, diethyl phosphite, and diisopropyl phosphite) was examined in detail. The only successful condit...

journal_title：Steroids

authors： Skoda-Földes R,Kollár L,Horváth J,Tuba Z

更新日期：1995-12-01 00:00:00

abstract：:To investigate the effects of conjugated bile acid on bacterial growth and cholylglycine hydrolase activity, Clostridium perfringens from human feces was exposed to varying concentrations of taurine- or glycine-conjugated chenodeoxycholic acid. Extracellular enzyme activity was determined by deconjugation of radiolabe...

journal_title：Steroids

authors： Kishinaka M,Umeda A,Kuroki S

更新日期：1994-08-01 00:00:00

abstract：:Sleep apnea is a disorder, which increasingly affects people worldwide. Whether the associated hypoxic events during sleep are central or obstructive in origin, the end result is excessive daytime sleepiness and an increased risk for several comorbidities, such as cardiovascular and neurodegenerative disorders. Sleep ...

journal_title：Steroids

authors： Snyder B,Cunningham RL

更新日期：2018-05-01 00:00:00

abstract：:We recently characterized the awakening responses and daily profiles of the catabolic stress hormone cortisol in elite military men. Anabolic hormones follow a similar daily pattern and may counteract the catabolic effects of cortisol. This companion report is the first to characterize daily profiles of anabolic hormo...

journal_title：Steroids

authors： Taylor MK,Kviatkovsky SA,Hernández LM,Sargent P,Segal S,Granger DA

更新日期：2016-06-01 00:00:00

abstract：:Biologic sex and sex steroids are important factors in clinical and experimental stroke. This review evaluates key evidence that biological sex strongly alters mechanisms and outcomes from cerebral ischemia. The role of androgens in male stroke is understudied and important to pursue given that male sex is a well know...

journal_title：Steroids

authors： Cheng J,Hurn PD

更新日期：2010-11-01 00:00:00

abstract：:The left adrenal of two female dogs were perfused with either 3 muCi [4-14C]cpd. S (2) and 45 muCi [1, 2-3H] 21-deoxycortisone (Dog I), or with 1 muCi [4-14C] 17-hydroxyprogesterone and 65 muCi [1,2-3H] 21-deoxycortisone (Dog II). In Dog I, 40% of the perfused 21-deoxycortisone was converted to cortisone and 23% of cp...

journal_title：Steroids

authors： Horn H,Halperin G,Weidenfeld J,Mordohovich D,Maschler I

更新日期：1977-08-01 00:00:00

abstract：:Inflammatory cytokines interleukin-1 (IL-1) and tumor necrosis factor-α (TNF-α) regulate the activity of the hypothalamo-pituitary-adrenal (HPA) axis at several levels. Although hypothalamic CRH secretion may be the primary mechanism by which these cytokines activate the HPA axis, IL-1 expression is increased within t...

journal_title：Steroids

authors： Tkachenko IV,Jääskeläinen T,Jääskeläinen J,Palvimo JJ,Voutilainen R

更新日期：2011-09-01 00:00:00