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Smith-Lemli-Opitz syndrome (SLOS) is an autosomal recessive, multiple malformation/mental retardation syndrome with an estimated incidence among individuals of European ancestry of 1 in 20,000 to 1 in 30,000. It is caused by inactivity of the enzyme 7-dehydrosterol-Δ 7 -reductase, which catalyses the terminal transformation in cholesterol synthesis. Patients show not only an increased level...
The previously reported analog of pregnenolone having a 3,4-dihydro-2H-pyran attached via a C C bond to the C-20 position (1), stereoselectively reacts with m-chloroperoxybenzoic acid in methanol at -5 o C. Acid-catalyzed hydrolysis of the isolated intermediates gives good yields of mostly a new 27-norcholesterol analog: (20R,23R)-3,20,23,26-tetrahydroxy-27-norcholest-5-en-22-one-3-acetate...
Cortisol is metabolized to 6β-hydroxycortisol by human cytochrome P450-3A4 (CYP3A4), an important enzyme involved in the metabolism of a variety of exogenous and endogenous compounds. Both cortisol and 6β-hydroxycortisol are excreted in urine, and the ratio of these steroids has been proposed as an indicator of CYP3A4 activity. We evaluated within-person variability of this biomarker in 10 healthy...
We recently detected the formation of estradiol-17β (estradiol) dimers, linked together through a diaryl ether bond between the C-3 phenolic oxygen of one estradiol molecule and the 2- or 4-position aromatic carbon of another estradiol, following incubations of [ 3 H]estradiol with human liver microsomes or cytochrome P450 enzymes in the presence of NADPH. Using estradiol as the starting material,...
The applicability of homonuclear gradient enhanced NMR experiments is demonstrated in the structure determination of steroid derivatives using stigmasterol as a model compound. High resolution 1 H NMR spectra of steroids very often display well resolved multiplets usually in the low-field region, and these signals can be used as starting points in several selective NMR experiments to study...
Allylation of an 11-oxo-steroid, the protected adrenosterone, was studied to examine more closely the steric hindrance of such a ketosteroid. While the β face exhibits, as well known, a strong steric hindrance, the α side appears to be only relatively hindered. A high diastereoselectivity was observed in the addition of crotyl magnesium bromide.
22R-Hydroxycholesterol is an intermediate in the steroid biosynthesis pathway shown to exhibit a neuroprotective property against β-amyloid (1-42) (Aβ) toxicity in rat PCl2 and human NT2N neuronal cells by binding and inactivating Aβ. In search of potent 22R-hydroxycholesterol derivatives, we assessed the ability of a series of naturally occurring entities containing the 22R-hydroxycholesterol structure...
In this study, we investigated the binding characteristics of [ 3 H]Δ 5 -androstene-3β,17β-diol to rabbit vaginal cytosolic and nuclear extracts and in freshly excised intact tissue strips. [ 3 H]Δ 5 -Androstene-3β,17β-diol bound to a protein(s) in the vaginal nuclear extract with high affinity (K d =3-5nM) and limited capacity (50-100fmol/mg protein). No specific...
Photodegradation of loteprednol etabonate (5), a steroid anti-inflammatory drug, in the solid state, in aqueous suspension, and in aqueous acetonitrile solution has been investigated. Analysis by HPLC showed that the profile of photodegradation products in the solid state was qualitatively similar to that in the aqueous suspension, although the profile in the aqueous acetonitrile solution was considerably...
Analysis of the sterol fraction obtained from the Colombian Caribbean sponge Topsentia ophiraphidites revealed that this sponge is a rich source of C 30 and C 31 sterols. Among them, a new C 31 sterol, named ophirasterol, was isolated, and its structure was established as (22E,24R)-24-(1-buten-2-yl)cholesta-5,22-dien-3β-ol (1) by spectral means and comparison...
A qualitative liquid chromatography-electrospray ionization tandem mass spectrometry method was developed for screening of the abuse of 4-chlorodehydromethyltestosterone, danazol, fluoxymesterone, formebolone, metandienone, oxandrolone, and stanozolol. The introduced method measures simultaneously nine different 17-alkyl-substituted anabolic androgenic steroids or their unconjugated metabolites in...
The androgen receptor plays a pivotal role in the prostate. Its primary function is to provide responsive gene products for differentiation and growth, but under abnormal conditions it contributes to the development of prostate cancer. The goal of this review is to elucidate the molecular functions of the androgen receptor and its role in prostate cancer. Initially the function of the androgen receptor...
Characteristics of acyl-coenzyme A (acyl-CoA):steroid acyltransferase from the digestive gland of the oyster Crassostrea virginica were determined by using estradiol (E2) and dehydroepiandrosterone (DHEA) as substrates. The apparent K m and V max values for esterification of E2 with the six fatty acid acyl-CoAs tested (C20:4, C18:2, C18:1, C16:1, C18:0, and C16:0) were in...
Plasma concentrations of dehydroepiandrosterone (DHEA), 5-androstene-3β,17β-diol (AED), and 17β-estradiol (E2) in dairy cows and heifers and AED binding to uterine cytosolic estrogen receptor (ER) were studied. Plasma samples were collected from the subcutaneous abdominal (SA) and jugular (J) veins of heifers and cows in the non-pregnant state and at 15-45, 90-120, 180-210, and 250-280 days of pregnancy...
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