Estradiol Derivatives Research Articles

Synthesis of 14ß-cyanomethyl derivatives of estradiol and the estimation of their antineoplastic activity in vitro

14s-Cyanomethyl derivatives of estrone and estradiol have been synthesized starting from 3-benzoyloxyestra-1,3,5(10),14,16-pentaen-17-yl acetate. A comparative study of their cytotoxicity in breast carcinoma ZR-75-1, cervix uteri carcinoma M-HeLa, uterus leiomyosarcoma SK-UT-1B, breast adenocarcinoma MCF-7, ovary teratocarcinoma PA-1, acute myelogenous leukemia KG-1, and Burkitt’s lymphoma Raji cells has been performed.

Derivatization of estrogens enhances specificity and sensitivity of analysis of human plasma and serum by liquid chromatography tandem mass spectrometry

Estrogens circulate at concentrations less than 20pg/mL in men and postmenopausal women, presenting analytical challenges. Quantitation by immunoassay is unreliable at these low concentrations. Liquid chromatography tandem mass spectrometry (LC–MS/MS) offers greater specificity and sometimes greater sensitivity, but ionization of estrogens is inefficient. Introduction of charged moieties may enhance ionization, but many such derivatives of estrogens generate non-specific product ions originating from the “reagent” group. Therefore an approach generating derivatives with product ions specific to individual estrogens was sought.Estrogens were extracted from human plasma and serum using solid phase extraction and derivatized using 2-fluoro-1-methylpyridinium-p-toluenesulfonate (FMP-TS). Electrospray in positive mode with multiple reaction monitoring using a QTrap 5500 mass spectrometer was used to quantify “FMP” derivatives of estrogens, following LC separation.Transitions for the FMP derivatives of estrone (E1) and estradiol (E2) were compound specific (m/z 362→238 and m/z 364→128, respectively). The limits of detection and quantitation were 0.2pg on-column and the method was linear from 1–400pg/sample. Measures of intra- and inter-assay variability, precision and accuracy were acceptable (<20%). The derivatives were stable over 24h at 10°C (7–9% degradation). Using this approach, E1 and E2, respectively were detected in human plasma and serum: pre-menopausal female serum (0.5mL) 135–473, 193–722pmol/L; male plasma (1mL) 25–111, 60–180pmol/L and post-menopausal female plasma (2mL), 22–78, 29–50pmol/L.Thus FMP derivatization, in conjunction with LC–MS/MS, is suitable for quantitative analysis of estrogens in low abundance in plasma and serum, offering advantages in specificity over immunoassay and existing MS techniques.

Effectiveness of 2-methoxyestradiol in alleviating angiogenesis induced by intracranial venous hypertension.

OBJECT Intracranial dural arteriovenous fistulas (DAVFs) are complex intracranial vascular malformations that can lead to hemorrhage. The authors recently found that chronic local hypoperfusion seems to be the main cause of angiogenesis in the dura mater, which leads to the formation of DAVFs. As a natural derivative of estradiol, 2-methoxyestradiol (2-ME) has an antiangiogenic effect and can be used safely in patients with advanced carcinoid tumors. This study was conducted to examine the antiangiogenic effects of 2-ME on a rat DAVF model. METHODS Male Sprague-Dawley rats (n = 72) were used in the experiments. Intracranial venous hypertension was induced for modeling, and 2-ME was used in the early or late stage for treatment. The effects were examined by immunohistochemistry, Western blot analysis, and quantitative real-time polymerase chain reaction assays. RESULTS 2-Methoxyestradiol significantly reduced angiogenesis in the dura in early- and late-intervention treatment groups, as proven by the results of immunohistochemical staining, Western blotting, real-time polymerase chain reaction assays, and microvessel density counts. The antiangiogenic effect even lasted for up to 2 weeks after 2-ME cessation. CONCLUSIONS These data collectively suggest that 2-ME can reduce the angiogenic effect caused by venous hypertension in a rat DAVF model, mainly by suppressing the inhibitor of differentiation 1 (ID-1) and hypoxia-inducible factor 1α (HIF-1α) pathways.

Design and Synthesis of Some Estradiol Derivatives Using an Estradioldicarbaldehyde as Chemical Tool

Design and Synthesis of Some Estradiol Derivatives Using an Estradioldicarbaldehyde as Chemical Tool

Expression Patterns of the chgH:rfp Transgene in Response to 17α-Ethinylestradiol (EE2) Exposure in Marine Medaka Oryzias dancena

The functional utility of a transgenic marine medaka Oryzias dancena strain carrying the red fluorescent protein (RFP) gene driven by an endogenous choriogenin H (chgH) promoter was evaluated for its ability to detect waterborne <TEX>$17{\alpha}$</TEX>-ethinylestradiol (EE2), a synthetic estrogen derivative. The chgH:rfp transgenic marine medaka larvae showed an age-dependent tendency in the efficiency of EE2-mediated transgene expression, in which transgenic larvae older than 6 days post-hatching displayed a more effective response in their transgene expression to EE2 than did younger hatchlings. During experimental exposures to high concentrations of EE2 (200 to 1,000 ng/L), the transgenic responses in the hatchlings were broadly dose- and duration-dependent. With exposures using lower doses of EE2 (25, 50 and 100 ng/L), EE2-induced transgenic RFP was also observed in the transgenic larvae, although the lower doses required exposure of longer duration. Under the EE2 exposure and microscope assay conditions used in our study, transgenic marine medaka larvae exhibited a similar degree of EE2-mediated RFP phenotype expression at various salinity levels (0, 15 and 30 ppt).

Synthesis and evaluation of 7α-(3-[18F]fluoropropyl) estradiol

IntroductionSeveral lines of evidence suggest that C-7α-substituted estradiol derivatives are well tolerated by estrogen receptor (ER). In line with this hypothesis, we are interested in the design and synthesis of C-7α-substituted estrogens as molecular probes to visualize ER function. MethodsWe have synthesized 7α-(3-[18F]fluoropropyl) estradiol (C3-7α-[18F]FES) as a potential radiopharmaceutical for ER imaging by positron emission tomography (PET). In vitro receptor binding and in vivo biodistribution and blocking studies in mature female mice, and in vivo metabolite analysis were carried out. Furthermore, in vivo ER-selective uptake was confirmed using ER-positive T-47D and ER-negative MDA-MB-231 tumor-bearing mice. We also compared the in vivo biodistribution of C3-7α-[18F]FES with 16α-[18F]FES. ResultsC3-7α-[18F]FES was produced in moderate yields (30.7%±15.1%, decay corrected) with specific activity of 32.0±18.1GBq/μmol (EOS). The in vitro binding affinity of C3-7α-FES to the ERα isoform was sufficient and equivalent to that of estradiol. C3-7α-[18F]FES showed selective uptake in ER-rich tissues, such as the uterus (4.7%ID/g±1.2%ID/g at 15minutes) and ovary (4.0%ID/g±1.0%ID/g at 5minutes). The tissue time activity curves of these organs showed reversible kinetics, indicating suitability for quantitative analysis. The highest contrast was obtained at 120minutes after injection of C3-7α-[18F]FES in the uterus (uterus/blood=18, uterus/muscle=17.3) and ovary (ovary/blood=6.3, ovary/muscle=6.0). However, the level of selective uptake of C3-7α-[18F]FES was significantly lower than that of 16α-[18F]FES. Most radioactivity in the uterus was detected in unchanged form, although peripherally C3-7α-[18F]FES was rapidly degraded to hydrophilic metabolites. In accordance with this peripheral metabolism, gradual increases in bone radioactivity were observed, indicating defluorination. Coinjection with estradiol dose-dependently inhibited C3-7α-[18F]FES uptake in the uterus and ovary. The in vivo IC50 values of estradiol in the uterus and ovary were 34.4 and 38.5nmol/kg, respectively. Furthermore, in vivo tumor uptake of C3-7α-[18F]FES was significantly higher (unpaired t test with Welch’s correction; p=0.015) in ER-positive T-47D tumors (2.3%ID/g±0.4%ID/g) than ER-negative MDA-MB-231 tumors (0.9%ID/g±0.1%ID/g). ConclusionsAlthough extensive metabolism was observed in rodents, C3-7α-[18F]FES showed promising results for quantitative analysis of ER density in vivo. However, the selective uptake of C3-7α-[18F]FES was lower than that of 16α-[18F]FES. Further optimizations and structure–activity relationship studies of the C-7α-substituted estradiol are needed.

Lipid nanocarriers of a lipid-conjugated estrogenic derivative inhibit tumor growth and enhance cisplatin activity against triple-negative breast cancer: pharmacokinetic and efficacy evaluation.

Breast cancer is the leading cause of malignancies among women globally. The triple negative breast cancer (TNBC) subtype is the most difficult to treat and accounts for 15% of all cases. Targeted therapies have been developed for TNBC but come short of clinical translation due to acquired tumor resistance. An effective therapy against TNBC must combine properties of target specificity, efficient tumor killing, and translational relevance. The objective of this study was to formulate a nontoxic, cationic, lipid-conjugated estrogenic derivative (ESC8), with demonstrated anticancer activity, for oral delivery in mice bearing triple negative breast cancer (TNBC) as xenograft tumors. The in vitro cell viability, Caco-2 permeability, and cell cycle dynamics of ESC8-treated TNBC cells were investigated. ESC8 was formulated as liposomes, solid lipid nanoparticles (SLNs), and nanostructured lipid carriers (NLCs) and characterized for size, zeta potential, entrapment efficiency, size stability, and tumor biodistribution. Pharmacokinetic modeling of plasma concentration-time course data was carried out following intravenous and oral administration in Sprague-Dawley rats. In vivo efficacy investigation of ESC8-SLNC was carried out in Nu/Nu mice bearing MDA-MB-231 TNBC as xenograft tumors, and the molecular dynamics modulating tumor growth inhibition was analyzed by Western blot. In vitro ESC8 inhibited TNBC and non-TNBC cell viability with IC50 ranging from 1.81 to 3.33 μM. ESC8 was superior to tamoxifen and Cisplatin in inhibiting MDA-MB-231 cell viability; and at 2.0 μM ESC8 enhanced Cisplatin cytotoxicity 16-fold. Intravenous ESC8 (2.0 mg/kg) was eliminated at a rate of 0.048 ± 0.01 h(-1) with a half-life of 14.63 ± 2.95 h in rats. ESC8 was orally bioavailable (47.03%) as solid lipid nanoparticles (ESC8-SLN). ESC8-SLN (10 mg/kg/day, ×14 days, p.o.) inhibited breast tumor growth by 74% (P < 0.0001 vs control) in mice bearing MDA-MB-231 cells as xenografts; and when given in combination with Cisplatin (2.0 mg/kg/biweekly, ×2 weeks, IV), tumor growth was inhibited by 87% (P = 0.0002, vs ESC8-SLN; 10 mg/kg/day, ×14 days, p.o). ESC8-SLN tumor growth inhibition was associated with increased expression of p21 and Caspase-9; as well as by inhibition of EGFR, Slug, p-Akt1, Vimentin, NFkβ, and IKKγ. These results show the promise of ESC8 as an oral adjuvant or neoadjuvant against triple negative breast cancer.

A click approach to novel D-ring-substituted 16α-triazolylestrone derivatives and characterization of their antiproliferative properties.

A simple and efficient synthesis of novel, D-ring substituted estrone derivatives containing a 16α-triazolyl moiety is described. Two epimeric azido alcohols (16α-azido-17α-hydroxy and 16α-azido-17β-hydroxy) of estra-1,3,5(10)-triene-3-methyl ether were prepared, followed by copper(I)-catalyzed azide-alkyne cycloaddition with various terminal alkynes. The steroidal triazoles were obtained in high yields and their activities against three human cancer cell lines (HeLa, MCF7 and A431) were screened. The most effective analogs were submitted to additional experiments in order to characterize their antiproliferative properties. As evidenced by flow cytometry, the selected steroids induced a disturbance in the HeLa cell cycle in a concentration- and exposure-dependent manner, through an increase of the hypodiploid population (subG1) and a cell cycle arrest in the G2/M phase. A noncancerous human fibroblast cell line (MRC5) was used to determine the selectivities of these compounds. Fluorescent microscopy after Hoechst 33258 - propidium iodide (HOPI) double staining revealed nuclear condensation and disturbed cell membrane integrity. The enhanced activities of caspase-3 and caspase-9 without activation of caspase-8 in the treated cells indicated the activation of the intrinsic pathway of apoptosis. The levels of cell cycle regulators (CDK1, cyclin B1/B2 and cdc25B) were decreased and the ratio Bax/Bcl-2 was increased 24 h after the treatment of HeLa cells (determined at an mRNA level by means of an RT-PCR technique). Under the same conditions, two agents elicited substantially increased degrees of phosphorylation of stathmin, as evidenced by Western blotting. The presented results demonstrate that these steroids can be regarded as appropriate structural scaffolds for the design and synthesis of further steroid analogs as innovative drug candidates with good efficacy.

ChemInform Abstract: Interaction of 16‐Hydroxymethylidene Derivatives of Androstane and Estrone with Thiohydrazides of Oxamic Acids.

AbstractThe title reaction leads to thiohydrazones which cyclize in situ in refluxing AcOH furnishing thiadiazole derivatives (IV) and (V) in good yield.

Chemometric estimation of the retention behavior of selected estradiol derivatives

Quantitative structure-retention relationship (QSRR) analysis has been performed in order to correlate the retention of selected estradiol derivatives with their calculated molecular lipophilicity. The lipophilicity descriptors were derived computationally and most important were selected. Linear regression (LR) Wad used for model establishing. Statistical quality of the generated models was determined by standard statistical and crossvalidation statistical parameters. Statistically significant and physically meaningful models were obtained. The prediction results are very well correlated with the experimentally observed data. Given predictive ability of the established models indicates that they could be used for predicting the chromatographic behavior of the similar molecules in normal-phase high-performance thin-layer chromatography.

Improved profiling of estrogen metabolites by orbitrap LC/MS

Estrogen metabolites are important biomarkers to evaluate cancer risks and metabolic diseases. Due to their low physiological levels, a sensitive and accurate method is required, especially for the quantitation of unconjugated forms of endogenous steroids and their metabolites in humans. Here, we evaluated various derivatives of estrogens for improved analysis by orbitrap LC/MS in human serum samples. A new chemical derivatization reagent was applied modifying phenolic steroids to form 1-methylimidazole-2-sulfonyl adducts. The method significantly improves the sensitivity 2–100 fold by full scan MS and targeted selected ion monitoring MS over other derivatization methods including, dansyl, picolinoyl, and pyridine-3-sulfonyl products.

Cycloaddition of oestrogen-like molecules on fullerene: theoretical approach

The [2+2] cycloaddition reaction between a double bond from a fullerene and an oestrogen or similar organic derivative has been studied in the scheme of the ab initio atom-centred density matrix propagation molecular dynamics model. The reaction was simulated considering vacuum, a little polar medium (butyric acid) and a strong polar medium (water). The results are completely different with the change of environments; some leading to an unidentified broken species without identification, whereas others produced a defined organic complex. The reaction stages have been analysed here and possible applications for medicine are achieved.

Influence of the rigidity of the steroid core in the structure of chiral dopants on the temperature dependence of cholesteric short pitch

New chiral compounds of the steroid type, namely, 3-alkanoyl- and 3-alkyl derivatives of 16-arylidene estrone, were synthesized and exhibited high helical twisting power (HTP) in nematic liquid crystals E63 and LC-1289. The peculiarities of the molecular structure of chiral compounds (CCs) and their high degree of chirality were discussed. Quite small concentrations of chiral compounds in both nematic solvents were needed to obtain a short-pitch cholesteric helical macrostructure with the selective light reflection in the visible range of the spectrum. The insignificant temperature dependence of the maximum wavelength of the selective light reflection obtained on the whole cholesteric range for all studied liquid crystalline (LC) systems could be related to relatively rigid molecular structure of the chiral compounds. The cholesteric LC mixtures comprising 3-alkanoyl- and 3-alkyl derivatives of 16-arylidene estrone were characterized by the phase stability and the stability of reflective characteristics in time that makes it possible to consider this series of dopants as appropriate for development of bistable cholesteric reflective LC displays.

Antihormonal potential of selected D-homo and D-seco estratriene derivatives

Since many estrogen derivatives exhibit anti-hormone or enzyme inhibition potential, a large number of steroidal derivatives have been synthesised from appropriate precursors, in order to obtain potential therapeutics for the treatment of hormone-dependent cancers. In molecular docking studies, based on X-ray crystallographic analysis, selected D-homo and D-seco estratriene derivatives were predicted to bind strongly to estrogen receptor α (ERα), aromatase and 17,20 lyase, suggesting they could be good starting compounds for antihormonal studies. Test results in vivo suggest that these compounds do not possess estrogenic activity, while some of them showed weak anti-estrogenic properties. In vitro anti-aromatase and anti-lyase assays showed partial inhibition of these two enzymes, while some compounds activated aromatase. Aromatase activators are capable of promoting estrogen synthesis for treatment of pathological conditions caused by estrogen depletion, e.g. osteopenia or osteoporosis.

Synthesis, Biological Evaluation and the Rationalisation of the Inhibitory Activity of a Range of Sulfonate Derivatives of Estrone (E1) in the Design of Reversible Inhibitors of Estrone Sulfatase (ES)

Synthesis, Biological Evaluation and the Rationalisation of the Inhibitory Activity of a Range of Sulfonate Derivatives of Estrone (E1) in the Design of Reversible Inhibitors of Estrone Sulfatase (ES)

Novel 99mTc-labelled estrogen derivative as potential agent for estrogen receptors imaging

Novel 99mTc-labelled estrogen derivative as potential agent for estrogen receptors imaging

Biodistribution of 99mTc–2-aminoestrone-3-methyl ether as a potential radiotracer for inflammation imaging

Estrogens may have pro- and anti-inflammatory properties depending on the situation and the involved tissue. 2-Aminoestrone-3-methyl ether as an estrogenic derivative was prepared with a yield of 55 % and well characterized. 99mTc–2-aminoestrone-3-methyl ether radiotracer was synthesized to study its inflammatory binding specificity as a novel selective radiopharmaceutical for inflammation imaging. In-vivo biodistribution study of 99mTc–2-amino estrone-3-methyl ether complex in both bacterial infection and sterile inflammation showed high and rapid accumulation of 99mTc–2-aminoestrone-3-methyl ether complex at the site of sterile inflammation compared to bacterial infection sites (target-to-non target ratio equal to 4.12 ± 0.02). This high biological accumulation in inflamed cells suggests that 99mTc–2-aminoestrone-3-methyl ether complex may be suitable as a potential selective radiotracer able to image inflammatory sites.

Synthesis of an Estradiol Derivative with an Adenosine-phosphate Mimic Linked at Position 16&amp;#946;

Synthesis of an Estradiol Derivative with an Adenosine-phosphate Mimic Linked at Position 16&amp;#946;

Oligosaccharide shells as a decisive factor for moderate and strong ionic interactions of dendritic poly(ethylene imine) scaffolds under shear forces.

For better understanding and improving the non-covalent interactions of dendritic core-shell, we evaluated the interactions of hyperbranched poly(ethylene imine) (PEI) decorated with various oligosaccharide shells with water-soluble B vitamins, an estradiol derivative and pantoprazole. Depending on the different properties of the analyte molecules, dendritic core-shell glyco architectures showed (very) weak, moderate and strong interactions with the analyte molecules. Thus, ionic interactions are the strongest driving force for the formation of host-guest complexes. The core-shell glyco architecture is a necessary prerequisite for stable analyte/PEI complexes; the pure hyperbranched PEI did not show any sufficiently strong interactions with neutral, cationic or anionic analytes under the shear forces applied during ultrafiltration of pure aqueous solution without an adjusted pH. Thus, only robust non-covalent interactions between analytes and the dendritic polyamine scaffold of the glycopolymer structure survive this separation step and allow isolation of stable host-guest complexes in aqueous solution.

Cover Picture: Selective Bromination of sp3 CH Bonds by Organophotoredox Catalysis (Asian J. Org. Chem. 4/2014)

The classical nature of bromination of alkanes and photoredox chemistry is signified by the greyscale in the background photo. In contrast, the brighter choice of color highlights the renaissance of photoredox chemistry. In particular, Choon Hong Tan and co-workers report a photoredox bromination which uses an organic dye as photoredox catalyst in their Full Paper on page 536 ff. Selective bromination of sclareolide and estrone derivatives was demonstrated. A radical relay to generate the CH-abstracting species from morpholine was proposed through experimental and computational studies. Photo credit: Chan Ke Min.