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 regioisomers of new condensed pyrazolines in a ratio of 2:1. The main product was the isomer obtained by the attack of the N-terminus of the 1,3-dipole on the carbon atom beta to the carbonyl group of the dipolarophile. The nitrilimine cycloadditions to the 16-methylene-17-ketones of 13alpha-estrone 3-methyl and 3-benzyl ether stereo- and regioselectively furnished spiropyrazolines. The attack of the N-terminus of the dipole occurred on the alpha-carbon of the alpha,beta-unsaturated ketones. The reactions were performed under both homogeneous and heterogeneous conditions. Silver acetate as a base proved more effective than its triethylamine counterpart. Changes in regio- and stereoselectivities were not observed on variation of the conditions of the cycloaddition reactions. The structures of the new products were determined by NMR (one- and two-dimensional) and MALDI TOF MS techniques, with C(70) fullerenes as matrix in the latter case.
journal_name
Steroidsjournal_title
Steroidsauthors
Mernyák E,Kozma E,Hetényi A,Márk L,Schneider G,Wölfling Jdoi
10.1016/j.steroids.2009.02.001subject
Has Abstractpub_date
2009-06-01 00:00:00pages
520-5issue
6eissn
0039-128Xissn
1878-5867pii
S0039-128X(09)00026-9journal_volume
74pub_type
杂志文章相关文献
STEROIDS文献大全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
pub_type： 杂志文章
doi：10.1016/0039-128x(81)90032-5
更新日期：1981-08-01 00:00:00
abstract：:Propargyl amine was protected by condensing it with 2,5-hexane-dione to give 2,5-dimethyl-N-(2'-propyn-1'-yl)pyrrole (2). The latter was converted to the corresponding Grignard reagent with ethylmagnesium bromide, and then condensed with estrone tetrahydropyranyl ether to give 17 alpha-[3'-(2'',5''-dimethyl-1''-pyrryl...
journal_title：Steroids
pub_type： 杂志文章
doi：10.1016/0039-128x(86)90005-x
更新日期：1986-09-01 00:00:00
abstract：:Here we report on the progress we have made in elucidating the mechanisms through which estrogen alters synaptic responses in hypothalamic neurons. We examined the modulation by estrogen of the coupling of various receptor systems to inwardly rectifying and small conductance, Ca(2+)-activated K(+) (SK) channels. We us...
journal_title：Steroids
pub_type： 杂志文章,评审
doi：10.1016/s0039-128x(01)00181-7
更新日期：2002-05-01 00:00:00
abstract：:Radioactive mestranol (ME) and/or ethynylestradiol (EE) were administered to women in Nigeria, Sri Lanka, and the USA, and the types and patterns of radioactive urinary conjugates examined by Sephadex LH-20 chromatography. There are no differences in the total excretion of urinary radioactivity over 3 days. Consistent...
journal_title：Steroids
pub_type： 杂志文章
doi：10.1016/0039-128x(80)90001-x
更新日期：1980-09-01 00:00:00
abstract：:Steroidogenesis begins with the metabolism of cholesterol to pregnenolone by the inner mitochondrial membrane cytochrome P450 side-chain cleavage (P450scc) enzyme. The rate of steroid formation, however, depends on the rate of cholesterol transport from intracellular stores to the inner mitochondrial membrane and load...
journal_title：Steroids
pub_type： 杂志文章,评审
doi：10.1016/s0039-128x(96)00154-7
更新日期：1997-01-01 00:00:00
abstract：:Progesterone and its polar metabolite(s) trigger the meiotic divisions in the amphibian oocyte through a non-genomic signaling system at the plasma membrane. Published site-directed mutagenesis studies of ouabain binding and progesterone-ouabain competition studies indicate that progesterone binds to a 23 amino acid e...
journal_title：Steroids
pub_type： 杂志文章
doi：10.1016/j.steroids.2012.04.012
更新日期：2012-09-01 00:00:00
abstract：:Human placental estradiol 17 beta-dehydrogenase (E.C. 1.1.1.62) was inactivated at pH 6.3 by 3-bromo [2'-14C] acetoxy-1,3,5(10) estratrien-17-one, a know substrate. The affinity-alkylated enzyme was then hydrolyzed by trypsin. Radioactive peptides were initially isolated by gel filtration and identified according to w...
journal_title：Steroids
pub_type： 杂志文章
doi：10.1016/0039-128x(82)90084-8
更新日期：1982-02-01 00:00:00
abstract：:An efficient method to prepare 5, 9-cyclo-1, 11-oxido-pregn-16-ene-3, 20-dione in one pot was reported. Treatment of 9-bromide-11-hydroxypregna-1, 4, 16-trien-3, 20-dione with Raney Ni in absolute ethanol afforded 5, 9-cyclo-1, 11-oxido-pregn-16-ene-3, 20-dione by two annulation reactions in reasonable yield. The abso...
journal_title：Steroids
pub_type： 杂志文章
doi：10.1016/j.steroids.2008.10.018
更新日期：2009-02-01 00:00:00
abstract：:The 3alpha,5alpha- and 3alpha,5beta-reduced derivatives of progesterone, deoxycorticosterone, dehydroepiandrosterone and testosterone enhance GABAergic neurotransmission and produce inhibitory neurobehavioral and anti-inflammatory effects. Despite substantial information on the progesterone derivative (3alpha,5alpha)-...
journal_title：Steroids
pub_type： 临床试验,杂志文章
doi：10.1016/j.steroids.2008.12.015
更新日期：2009-04-01 00:00:00
abstract：:This study examines the distribution of 5 alpha-reductase and 3 alpha(beta)-hydroxysteroid dehydrogenase activities throughout the intact hyperplastic prostate gland and relate these measurements to the fibromuscular/epithelial composition and to the gross glandular morphology. The relative capacities of the stroma an...
journal_title：Steroids
pub_type： 杂志文章
doi：10.1016/0039-128x(83)90015-6
更新日期：1983-01-01 00:00:00
abstract：:We have monitored the effect of ergosterol on electrical capacitance and electrical resistance of the phosphatidylcholine bilayer membranes using chronopotentiometry method. The chronopotentiometric characteristic of the bilayers depends on constant-current flow through the membranes. For low current values, no electr...
journal_title：Steroids
pub_type： 杂志文章
doi：10.1016/j.steroids.2011.05.009
更新日期：2011-09-01 00:00:00
abstract：:Five new steroidal alkaloids, 5,14-dehydro-N(a)-demethylsaracodine [3beta-N(a)-methyl-20S-N(b)-acetyl-N(b)-methylamino-pregn-5,14-diene] (1), 14-dehydro-N(a)-demethylsaracodine [3beta-N(a)-methyl-20S-N(b)-acetyl-N(b)-methylamino-5alpha-pregn-14-ene] (2), 16-dehydrosarcorine [(20S)-20-(N,N-dimethylamino)-3beta-(N(a)-ac...
journal_title：Steroids
pub_type： 杂志文章
doi：10.1016/j.steroids.2004.03.016
更新日期：2004-10-01 00:00:00
abstract：:Glucocorticoids are important regulators of metabolism and immune function. Synthetic glucocorticoids are extensively used for immunosuppression/anti-inflammatory therapy. Since the glucocorticoid receptor (GR) is central to most hormone effects; its in vivo regulation will influence hormone/drug action. An alternativ...
journal_title：Steroids
pub_type： 杂志文章
doi：10.1016/j.steroids.2012.11.014
更新日期：2013-02-01 00:00:00
abstract：:The 11 beta-hydroxysteroid dehydrogenase type II enzyme (11 beta HSD2) converts cortisol to cortisone, allowing the non-selective mineralocorticoid receptor to bind aldosterone. When the activity of this enzyme is compromised, as occurs in licorice intoxication or in the congenital syndrome of apparent mineralocortico...
journal_title：Steroids
pub_type： 杂志文章
doi：10.1016/0039-128x(96)00013-x
更新日期：1996-04-01 00:00:00
abstract：:Bile acid salts are biosurfactants which form mixed micelles with phospholipids in vertebrates. These mixed micelles are suitable for solubilisation of cholesterol. For therapeutic purposes some bile acid salts as sodium ursocholate are used. However, bile acid anions possess low capacity for solubilisation of cholest...
journal_title：Steroids
pub_type： 杂志文章
doi：10.1016/j.steroids.2014.04.018
更新日期：2014-08-01 00:00:00
abstract：:Smith-Lemli-Opitz syndrome (SLOS) is a malformation syndrome associated with 7-dehydrocholesterol (7DHC) 7-reductase deficiency. Although SLOS can be detected in an affected fetus before midpregnancy by measurement of 7DHC levels in amniotic fluid or chorionic villus cells, a noninvasive, more routine method is needed...
journal_title：Steroids
pub_type： 杂志文章
doi：10.1016/s0039-128x(99)00026-4
更新日期：1999-07-01 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
pub_type： 杂志文章
doi：10.1016/0039-128x(86)90027-9
更新日期：1986-11-01 00:00:00
abstract：:The enterohepatic circulation and metabolism of ethynodiol diacetate (3beta,17beta-diacetoxy-17alpha-ethynyl-estr-4-ene) in baboons were studied following the intravenous injection of this contraceptive steroid labeled with 14C (4-position) and with 3H (in either the 3- or 17-acetoxy moieties). Bile and urine from fou...
journal_title：Steroids
pub_type： 杂志文章
doi：10.1016/0039-128x(75)90048-3
更新日期：1975-06-01 00:00:00
abstract：:The syndrome of apparent mineralocorticoid excess (AME) is an inherited form of hypertension in which 11 beta-hydroxysteroid dehydrogenase (11-HSD) is defective. This enzyme converts cortisol to its inactive metabolite, cortisone. The deficiency allows mineralocorticoid receptors to be occupied by cortisol, because th...
journal_title：Steroids
pub_type： 杂志文章,评审
doi：10.1016/s0039-128x(96)00164-x
更新日期：1997-01-01 00:00:00
abstract：:This article describes the oxidation of cholesta-5,7-dien-3beta-yl acetate (4) with the urea-hydrogen peroxide adduct (UHP) using methyltrioxorhenium (MTO) as catalyst, under various conditions. Specifically, the effects of using different solvents (CHCl(3) and ethers) and additives (EtOH and pyridine) on the course o...
journal_title：Steroids
pub_type： 杂志文章
doi：10.1016/s0039-128x(02)00017-x
更新日期：2002-06-01 00:00:00
abstract：:Tibolone is a highly effective postmenopausal hormone treatment that has its biological activity dependent on metabolism to 3alpha- and 3beta-OH tibolone, which bind solely to the estrogen receptor. Despite the high levels of estrogen receptor-binding metabolites in the circulation, the endometrium becomes atrophic, s...
journal_title：Steroids
pub_type： 杂志文章
doi：10.1016/j.steroids.2005.04.010
更新日期：2005-11-01 00:00:00
abstract：:Brassinosteroid (BR) phytohormones play indispensable roles in plant growth and development. Brassinolide (BL) and 24-epibrassinolide (24-epiBL) are the most active ones among the BRs reported thus far. Unfortunately, the extremely low natural content and intricate synthesis process limit their popularization in agric...
journal_title：Steroids
pub_type： 杂志文章
doi：10.1016/j.steroids.2015.09.002
更新日期：2015-12-01 00:00:00
abstract：:Saturation analysis of the binding of [3H]dexamethasone [( 3H]DEX) to ammonium sulfate precipitates (ASPs) confirmed the presence of a limited-capacity, high-affinity binder in human adipose tissue cytosols. Various non-radioactive steroids competed with [3H]DEX for binding to the ASPs in the following sequence: dexam...
journal_title：Steroids
pub_type： 杂志文章
doi：10.1016/0039-128x(87)90091-2
更新日期：1987-06-01 00:00:00
abstract：:Inhibitors of estrogen 2-hydroxylase can be utilized in studying the kinetics of this cytochrome P450 enzyme complex and in elucidating the structural requirements of the active site. The conversion of estrogens to 2-hydroxyestrogens in rat liver microsomal preparations was examined using two radiotracer assays, the c...
journal_title：Steroids
pub_type： 杂志文章
doi：10.1016/s0039-128x(83)90120-4
更新日期：1983-07-01 00:00:00
abstract：:The uterine milk (UTM) proteins are the major progesterone-regulated proteins secreted by the sheep uterus during pregnancy. Recently, proteins related to the UTM proteins have been identified in uterine secretions of the pregnant cow and sow. The present objective was to determine the time course for induction of the...
journal_title：Steroids
pub_type： 杂志文章
doi：10.1016/0039-128x(91)90022-n
更新日期：1991-12-01 00:00:00
abstract：:Based on histological criteria, Kingsley and Bogdanove (3) reported that the benzoate ester of 17beta-hydroxy-5alpha-androstan-3-one (5alpha-DHT), unlike testosterone propionate, is unable to induce vaginal mucification when given subcutaneously to rats. In contrats, Kennedy (4) found in estrogen-pretreated rats that ...
journal_title：Steroids
pub_type： 杂志文章
doi：10.1016/0039-128x(76)90061-1
更新日期：1976-03-01 00:00:00
abstract：:In each menstrual cycle only very few follicles in the mammalian ovary undergo maturation and ovulation while most of the follicles degenerate in the process of atresia. Moreover, in the absence of pregnancy, the newly formed corpora lutea will degenerate and disappear in the process of luteolysis. Recent studies sugg...
journal_title：Steroids
pub_type： 杂志文章,评审
doi：10.1016/0039-128x(96)00031-1
更新日期：1996-04-01 00:00:00
abstract：:Fourteen esters (formate, acetate, propionate, butyrate, hexanoate, heptanoate, and benzoate) located at C-11 of 11 beta-hydroxyesterone and 11 beta-hydroxyestradiol-17 beta were synthesized and evaluated for uterotropic and gonadotropin release inhibition in rats, as well as their ability to displace (3H) estradiol-1...
journal_title：Steroids
pub_type： 杂志文章
doi：10.1016/0039-128x(84)90063-1
更新日期：1984-01-01 00:00:00
abstract：:Gonadal steroids modulate adrenal gland size and function in a variety of species, and our previous studies demonstrate that circulating androgens suppress 3beta-hydroxysteroid dehydrogenase-isomerase (3betaHSD) activity in the adrenal cortex of male mice. The present study tests the hypothesis that androgens have a d...
journal_title：Steroids
pub_type： 杂志文章
doi：10.1016/s0039-128x(02)00023-5
更新日期：2002-07-01 00:00:00
abstract：:Recent studies by several research groups have shown that G protein estrogen receptor-1 (GPER) formerly known as GPR30, mediates 17beta-estradiol (E2) activation of signal transduction pathways in a variety of human cancer cells and displays E2 binding typical of a membrane estrogen receptor. However, the importance o...
journal_title：Steroids
pub_type： 杂志文章,评审
doi：10.1016/j.steroids.2009.11.005
更新日期：2010-08-01 00:00:00
