The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Although a clear role for estrogen receptor (ER) α has been established, the contribution of ERβ in estrogen-dependent development, growth and functions of the myometrium is not understood. As a first step towards understanding the role of ERβ, we have examined the expression of ERα and ERβ in the human myometrium. With competitive RT-PCR assays, the level of ERβ mRNA was 10–200 times lower than that...
The host–guest interaction between the steroid antibiotics sodium fusidate and potassium helvolate as guests and the hosts β- and γ-cyclodextrin was studied by 13C and 1H NMR techniques. The analysis of chemical shifts of individual nuclei leads to inconsistent values of the association constants and fails generally in the case of mixtures of 1:1 and 1:2 stoichiometries. The problem of parameter correlation...
Estrogen receptor α (ERα) is phosphorylated on multiple amino acid residues. For example, in response to estradiol binding, human ERα is predominately phosphorylated on Ser-118 and to a lesser extent on Ser-104 and Ser-106. In response to activation of the mitogen-activated protein kinase pathway, phosphorylation occurs on Ser-118 and Ser-167. These serine residues are all located within the activation...
The presence of estrone sulfatase in breast tumors and the high levels of circulating estrone sulfate may contribute the major portion of estrogen synthesized locally in breast tissues through conversion of estrone sulfate to estrone by the enzyme. Using inhibitors of estrone sulfatase for the treatment of estrogen-dependent (estrogen receptor positive, ER + ) breast cancer could be a very...
The complexation of two steroid antibiotics of the fusidane family, sodium fusidate and potassium helvolate, by β-CD and γ-CD has been studied by using 1D and 2D-NMR techniques. Both guests form 1:1 complexes with γ-CD and 1:2 (guest:cyclodextrin) complexes with β-CD. Thus, both antibiotics behave as monotopic and ditopic guests when they are complexed by γ-CD and β-CD, respectively. Both steroids...
The receptor profiles and in vivo activity of tibolone, and its primary metabolites, Δ 4 -isomer, and 3α- and 3β-hydroxytibolone, were studied and compared to those of structurally related compounds. The Δ 4 -isomer was the strongest binder and activator of the progesterone receptor (PR); tibolone was 10 times weaker in binding and half as potent in transactivation of PR; 3α- and 3β-hydroxytibolone...
Introduction: The products of estrogen metabolism may affect breast carcinogenesis. The 16α-hydroxyestrone (16-OHE) metabolite has a higher affinity for the estrogen receptor (ER) than the 2-hydroxyestrone (2-OHE) metabolite, while conjugated 2-OHE metabolite may inhibit angiogenesis. We investigated the association between the relative concentrations of these metabolites in urine (2-OHE/16-OHE) and...
Pregnane-3,17α,20-triols bearing unsaturation at Δ 7 , Δ 8 , Δ 5,7 , or Δ 5,8 have been tentatively identified as steroid metabolites in Smith–Lemli–Opitz syndrome (SLOS). Starting with 17α-hydroxypregnenolone diacetate, we have synthesized 13 unsaturated C 21 triols by four different routes in one to four steps. These multifunctional steroids were prepared...
Dehydroepiandrosterone (DHEA) is a naturally occurring steroid synthesized in the adrenal cortex, gonads, brain, and gastrointestinal tract, and it is known to have chemopreventive and anti-proliferative actions on tumors. These effects are considered to be induced by the inhibition of glucose-6-phosphate dehydrogenase (G6PD) and/or HMG-CoA reductase (HMGR) activities. The present study was undertaken...
A facile six-step synthesis of 2,2,3,4,4-d 5 -androsterone-β-d-glucuronide (1) starting from epiandrosterone (2) in 63% yield is described and compared with several alternative synthetic pathways. Compound 1 can be used as an internal standard in screening procedures for anabolic steroids to monitor the hydrolysis step of the steroid glucuronides prior to gas chromatography–mass spectrometry...
Corticosteroids regulate a variety of essential physiological functions, such as mineral balance and stress. The great interest in these steroids, especially the glucocorticoids, stems from roles they are thought to play in neuropsychiatric disorders, such as severe depression and anxiety.The development of glucocorticoid receptor (GR) ligands which are appropriately labeled with short-lived positron-emitting...
(20S)-[7,7,21,21- 2 H 4 ]-3β-(tert-Butyldimethylsilanyloxy)-20-methyl-pregn-5 -en-21-ol, an intermediate for the preparation of deuterated isotopomers of sterols to be used as standards for biomedical studies, was prepared by reduction with dichloroaluminum deuteride of ethyl (20S)-3β-(tert-butyldimethylsilanyloxy)-7-oxo-pregn-5-en-20-carboxylate. Using controlled experimental conditions,...
We report the first synthesis of the unnatural enantiomer of desmosterol (ent-desmosterol). The sterol nucleus was constructed enantiospecifically, followed by stepwise addition of the side chain. Beginning with ent-androst-4-ene-3,17-dione, ent-desmosterol was synthesized in 13 steps and 20% yield. Protected ent-desmosterol was subjected to catalytic deuteration to afford ent-deuterocholesterol....
Synthetic routes leading to 19E and 7Z O-(carboxymethyl)oximes derived from 16α-hydroxydehydroepiandrosterone were developed using two independent methods for introduction of the 16α-hydroxy group. Firstly, the oxime moiety was built, and then, either epoxidation of the enol acetate followed by the boron trifluoride mediated rearrangement or alkaline hydrolysis of the corresponding α-bromide in aqueous...
This study is concerned with an oral administration of 5mg of [1,2,4,19- 13 C 4 ,11α- 2 H]cortisol (cortisol- 13 C 4 , 2 H 1 ) to a human subject to reliably evaluate the individual activities of two isozymes of 11β-HSD. The use of a GC-MS method allowed the simultaneous measurement of the plasma concentrations of cortisol- 1 ...
The relation of adrenal function and aging has been the subject of intense interest in recent years. The circadian variations of plasma cortisol have been described in Caucasians, but little information is available on such hormone variations among the Chinese population, especially its changes with age. This study was, therefore, designed to examine the effects of age on the circadian variations...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.