Estradiol Derivatives Research Articles

High affinity 17α-substituted estradiol derivatives: Synthesis and evaluation of estrogen receptor agonist activity

We synthesized four derivatives of 17β-estradiol (E2) with an azide substitution on a 17α-side chain of varying length, namely 17α-(azidopropargyl)-3,17β-estradiol ( 5), its 17β-azido derivative (diazide 7), 17α-(5-azido-pent-1-ynyl)-3,17β-estradiol ( 6) and 17α-(azidopentyn-2-yl)-3,17β-estradiol ( 10). While most of the derivatives had low ( 7) or marginal ( 6 and 10) relative binding affinity (RBA) for both types of estrogen receptor (ERα and ERβ), the RBAα and RBAβ of 5 were practically identical to those of E2. The estrogenic activity of the derivatives was assessed using estrogen-responsive breast (MCF-7) and endometrial cancer (Ishikawa) cells. While 5 was a potent and effective inducer of alkaline phosphatase in Ishikawa cells and 7 was less potent but as effective as 5, 6 was marginally active and 10 was totally inactive in this respect. In the presence of 0.1 nM E2, however, 6 exhibited some ER antagonist activity at the highest concentration tested (1 μM). Similar results were obtained as regards the potency and efficacy of stimulation of MCF-7 cell proliferation and induction of luciferase gene expression in MCF-7:D5L cells, a clone stably transfected with an estrogen-responsive form of the gene. These data suggest that, while 5, 6, 7 and 10 interact with either type of ER in isolation, only 5 and 7 exhibit substantial ER agonist activity in the different estrogen-target cells examined, which could provide for photoaffinity labelling of the receptor in the cell as well as in isolation.

Inactivation of the Pure Antiestrogen Fulvestrant and Other Synthetic Estrogen Molecules by UDP-Glucuronosyltransferase 1A Enzymes Expressed in Breast Tissue

Fulvestrant (Faslodex) is administered by intramuscular injection and is converted into ketone, sulfate, sulfone and glucuronide metabolites. Glucuronidation, catalyzed by 18 members of the UDP-glucuronosyltransferase (UGT) enzyme family, plays a major role in the elimination of natural estrogens. The present study was aimed at identifying and characterizing human UGT enzymes involved in the glucuronidation of this antiestrogen as well as other synthetic estrogen derivatives with aliphatic chains on the E2 molecule. In contrast to E2, which is conjugated by UGT1A1, -1A3, -1A8, -1A10, and -2B7, fulvestrant is glucuronidated by UGT1A1, -1A3, -1A4, and -1A8. The four UGT1A-fulvestrant conjugating enzymes glucuronidate this substrate at position 3, whereas only UGT1A8 also produces fulvestrant-17-glucuronide. For E2, only UGT1A3 and UGT2B7 are capable to conjugate at 17-hydroxyposition. These observations indicate that addition of an aliphatic chain to the E2 molecule modifies the specificity of the UGT enzymes toward the C18 molecules. To further investigate the specificity of these enzymes, a series of E2 derivatives with aliphatic or phenyl chains at position 2, 7alpha, and 11beta was also tested for its conjugation with human UGT enzymes. It was observed that, in addition to UGT1A3, UGT1A1 and UGT1A8 also played important roles for the glucuronidation of these compounds. This suggests that the basic structure of E2 is one of the major determinants for the glucuronidation catalyzed by this group of enzymes. Considering the high level of UGT1A3 and -1A4 expression in the gastrointestinal tract and mammary gland, our results suggest that fulvestrant can be inactivated both in intestine and in its target tissue.

Alternative QSAR models for selected estradiol and cytochrome P450 ligands: comparison between classical, spectroscopic, CoMFA and GRID/GOLPE methods

The performance of the spectroscopic EVA (eigenvalue) and EEVA (electronic eigenvalue) methods was tested with data sets applying coumarin 7-hydroxylation inhibitors (28 compounds) for cytochrome P450 mouse CYP2A5 and human CYP2A6 enzymes and 11β-, 16α-, and 17α-substituted estradiol derivatives (30 compounds) for the lamb uterine estrogen receptor, and compared with the performance of the classical Hansch-type, CoMFA and GRID/GOLPE methods. Besides the internal predictability, the external predictability of the models was tested with several randomized training and test sets to ensure the validity and reliability of the models. Partial least squares (PLS) regression was employed as a general statistical tool with the EVA and EEVA methods. Some supplementary models were also built using only one PLS component with McGowan's volumes (MgVol and MgVol2) as additional descriptors and employing multiple linear regression (MLR) as the modelling tool. In general, both the internal and external performance of the EVA model, and more especially the EEVA model, with one PLS component and MgVol parameters was satisfactory, being either as good as or clearly better than that of the Hansch-type, CoMFA and GRID/GOLPE models.

MTD—PLS: A PLS Variant of the Minimal Topologic Difference Method. Part 3. Mapping Interactions Between Estradiol Derivatives and the Alpha Estrogenic Receptor.

ChemInformVolume 36, Issue 49 Other Subjects MTD—PLS: A PLS Variant of the Minimal Topologic Difference Method. Part 3. Mapping Interactions Between Estradiol Derivatives and the Alpha Estrogenic Receptor. Ludovic Kurunczi, Ludovic Kurunczi Univ. Med. Pharm. “V. Babes”, RO-300041 Timisoara, Rom.Search for more papers by this authorEdward Seclaman, Edward Seclaman Univ. Med. Pharm. “V. Babes”, RO-300041 Timisoara, Rom.Search for more papers by this authorTudor I. Oprea, Tudor I. Oprea Univ. Med. Pharm. “V. Babes”, RO-300041 Timisoara, Rom.Search for more papers by this authorLuminita Crisan, Luminita Crisan Univ. Med. Pharm. “V. Babes”, RO-300041 Timisoara, Rom.Search for more papers by this authorZeno Simon, Zeno Simon Univ. Med. Pharm. “V. Babes”, RO-300041 Timisoara, Rom.Search for more papers by this author Ludovic Kurunczi, Ludovic Kurunczi Univ. Med. Pharm. “V. Babes”, RO-300041 Timisoara, Rom.Search for more papers by this authorEdward Seclaman, Edward Seclaman Univ. Med. Pharm. “V. Babes”, RO-300041 Timisoara, Rom.Search for more papers by this authorTudor I. Oprea, Tudor I. Oprea Univ. Med. Pharm. “V. Babes”, RO-300041 Timisoara, Rom.Search for more papers by this authorLuminita Crisan, Luminita Crisan Univ. Med. Pharm. “V. Babes”, RO-300041 Timisoara, Rom.Search for more papers by this authorZeno Simon, Zeno Simon Univ. Med. Pharm. “V. Babes”, RO-300041 Timisoara, Rom.Search for more papers by this author First published: 09 November 2005 https://doi.org/10.1002/chin.200549202AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume36, Issue49December 6, 2005 RelatedInformation

Synthesis of DTPA-attached estradiol derivative and determination of its radiopharmaceutical potential

An estrogen derivative, β-estradiol or 1,3,5,(10)-estratriene-3,17β-diol) attached to diethylenetriamine pentaacetic acid (DTPA) was synthesized in six experimental steps. At the end of these steps, a DTPA-attached estradiol derivative called deoxy-demethyl homoestradiolyl-diethylenetriamine-pentaacetic acid (ESTDTPA) was obtained. The synthesized compounds were labeled with 99mTc. Thin layer radio chromatography (TLRC) was used to determine radiochemical yields and stabilities.Structural investigations confirmed the structures. The labeling yield was satisfactory (about 95%), and 99mTc-ESTDPTA was stable in neutral medium at room temperature for 5 hours. Biodistribution studies were performed on normal and DMBA-induced, tumor bearing female Albino Wistar rats. The activity per gram tissue was calculated, and time-activity curves were plotted. ESTDTPA uptake by uterus reached a level of 20.73% dose/g, showing a maximum within 5 minutes after injection. Ovary and breast showed similar biodistribution profiles. The kidneys, which are the primary organs of metabolism and excretion of estrogen, showed a high 99mTc-ESTDTPA uptake. The imaging studies were performed on normal and tumor bearing female Albino Wistar rats using a Camstar XR/T gamma-camera. Gamma-scintigraphy studies showed that tumors could be well visualized in a few minutes and clearly differentiated from other organs, such as bladder and liver by 24 hours.

Chromatographic Behaviour and Lipophilicity of Estradiol Derivatives

The retention behaviour of estradiol derivatives has been studied by HPLC on polar chemically bonded stationary phases: C3CN, DIOL and C3NH2, commercially available columns. The mobile phases used were: methanol-water and acetonitrile-water in various proportions. Reversed-phase chromatography occurred on polar chemically bonded stationary phases. Correlation between the retention constants of estradiol derivatives obtained on polar chemically bonded phases and log P calculated via different methods was examined too.

Synthesis and Estrogenic Activity Screening of Some 6,9‐Disubstituted Estradiol Derivatives.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Presence and estrogenicity of anthracene derivatives in coastal japanese waters

An analytical method was developed to measure levels of anthracene (ANT) and its derivative compounds 9,10-anthraquinone (ATQ) and eight hydroxy-anthraquinones (hATQs) in seawater from Tokyo Bay and Suruga Bay, Japan. The hATQs produced through photochemical reaction of ANT are known to be toxic. Seawater samples contained ANT at levels ranging from < 0.2 to 4.7 ng/L, ATQ from 3.9 to 200 ng/L, 1-hydroxyanthraquinone (1-hATQ) from < 0.9 to 5.3 ng/L, and 2-hATQ from 1.6 to 5.5 ng/L. The yeast two-hybrid system was also used to evaluate the estrogenic activity of these compounds. Estrogen agonist and antagonist tests with or without rat liver S9 were carried out. Some compounds showed estrogenic activity: The strongest (2-hydroxyanthraquinone) was of similar potency to p-nonylphenol. Concentrations of some estrogenic derivatives in the samples were higher than those of the parent ANT Polycyclic aromatic hydrocarbons (PAHs) such as ANT appear able to be transformed into toxic compounds in the environment when they are irradiated by sunlight, so it is important to monitor not only PAHs but also hydroxyl-PAH-quinones in the environment.

MTD−PLS: A PLS Variant of the Minimal Topologic Difference Method. III. Mapping Interactions between Estradiol Derivatives and the Alpha Estrogenic Receptor

A homogeneous collection of 45 estrogen agonist derivatives with relative binding affinities measured to the estrogen receptor from Ratus norvegicus was used. The quantitative structure-activity relationships were derived using an improved minimal topologic difference (MTD) method in a partial least-squares (PLS) variant. The spatially assigned analysis of fragment properties can provide receptor site maps, within the limits of the existing series. A steric misfit was found for the steroidal position 2; benefic hydrophobic and van der Waals (enhanced by high polarizability) interactions were found for the 17alpha-CH=CH-X group. MTD-PLS mapping results are confirmed by the experimentally derived estradiol-estrogen receptor binding site contacts (based on X-ray crystallography). Our results suggest that this MTD-PLS method can yield useful results for interactions with receptors of unknown 3D structure and, generally, for the steric rigidity of receptor sites.

Estrogen A-ring structure and antioxidative effect on lipoproteins

The oxidative modification of lipoprotein particles is an important step in atherogenesis. Estrogens are known to be powerful antioxidants independently of their binding to the estrogen receptors and the hormonal functions. We explored the structural determinants for the antioxidant activity of a large number of estrogen derivatives ( n = 43) in an aqueous lipoprotein solution in vitro by monitoring formation of conjugated dienes. Our results indicate that estrogen derivatives with an unsubstituted A-ring phenolic hydroxyl group with one or two adjacent methoxy groups provide strongest antioxidant protection of low density lipoprotein (LDL) and high density lipoprotein (HDL). The electron donating methoxy groups may enhance the antioxidant effect by weakening the phenolic O H bond and providing stability to the formed phenoxyl radical. With some exceptions, compounds completely lacking unsubstituted hydroxyl groups in the A-ring exhibited no antioxidant effect, e.g. the most hydrophilic “tetrol” compound with three unsubstituted A-ring hydroxyl groups had no antioxidant effect. Moreover, additional hydroxyl groups in the B-, C- or D-ring seemed to weaken the antioxidant effect. Accordingly, both the presence of unsubstituted hydroxyl groups and adjacent substituents, as well as the lipophilicity of the derivatives determine the antioxidant activity of estrogen derivatives in aqueous lipoprotein solutions.

Synthesis and Evaluation of (17α,20Z)-21-(4-Substituted-phenyl)-19-norpregna-1,3,5(10),20-tetraene-3,17β-diols as Ligands for the Estrogen Receptor-α Hormone Binding Domain: Comparison with 20E-Isomers

As part of our ongoing program to develop probes for the hormone binding domain of the estrogen receptor-alpha (ERalpha), we prepared and evaluated a series of 17alpha,Z-(4-substituted-phenyl)vinyl estradiol derivatives. The results indicated that the relative binding affinities (RBAs) at 25 degrees C for the new compounds were significant (RBA = 9-57) although less than that of estradiol (RBA = 100) or of the parent unsubstituted phenylvinyl estradiol (RBA = 66). All of the Z-compounds were full agonists in the uterotrophic assay, indicating that the ligands formed estrogen-like complexes with the estrogen receptor-alpha hormone binding domain (ERalpha-HBD). Comparison of corresponding Z- and E-4-substituted phenylvinyl ligands complexed with the ERalpha-HBD indicated small but significant differences in binding modes that may account for the differing trends seen in the structure-activity relationships for the two series.

Direct enzyme immunoassay of fecal estrone derivatives in dairy cows

ABSTRACTThe present study was undertaken to develop a novel, practical and simple procedure for enzyme‐linked immunosorbent assay of fecal estrone derivatives (estrone, estrone sulfate and estrone glucuronide) in dairy cows. Fecal solution, prepared by mixing feces with borate buffer, was applied directly to wells without extraction, and incubated with anti‐estrone antibody and horseradish peroxidase‐labeled estrone. Estrone sulfate was used as the standard. The sensitivity of the assay was estimated as 0.15 ng/mL (0.6 ng/g). The intra‐assay and inter‐assay coefficients of variation were 5.3–8.1% and 13.4–15.7%, respectively. The recovery rate was 78–102%. Only 4 h were needed to complete an assay to measure fecal estrone derivative concentrations. A significant positive correlation was established between plasma estrone sulfate concentrations and fecal estrone sulfate equivalent concentrations. When fecal estrone sulfate equivalent concentrations were measured in pregnant dairy cows, a gradual increase from day 150 of pregnancy, and subsequent drastic increases from day 240 to calving date were observed. These results suggest that the direct enzyme immunoassay procedure developed in the present study is a practical and reliable method for measuring fecal estrone derivative concentrations.

Synthesis of 131I labeled estrone derivatives and biodistribution studies on rats

The aim of this study is to synthesize novel 131I labeled estrone derivatives that may have therapeutical potentials on Estrogen Receptor rich tumors. Two radiolabeled estrone derivatives, [131I]2-iodo-3-methoxy-estra-1,3,5-trien-17-one and [131I]4-iodo-3-methoxy-estra-1,3,5-trien-17-one were synthesized. Ether amino estrone derivatives were obtained from estrone in three steps by means of diazonium compounds. Tissue distribution studies exhibited receptor-mediated uptake in target organs in female Albino Wistar rats. Maximum uptakes for 2-iodo[131I]-3-methoxy-estrone are in stomach, pancreas, intestines and uterus. A similar biodistribution profile was obtained for 4-iodo[131I]-3-methoxy-estrone. However 2-iodo-3-methoxy-estra-1,3,5-trien-17-one has higher uptake in stomach, kidneys, pancreas, and intestines than 4-iodo-derivative.

Amperometric Detection of Estradiol and its Metabolites in Menstrual Women and the Urine of Pregnant Rabbits

A liquid chromatography method with electrochemical detection has been developed for the quantitative measurement for the five estrogen derivatives (estrone, estradiol, estriol, 2‐methoxyestrone, and ethinylestradiol) in human and rabbit urine. The detection cell consisting of a dual thin‐layer glassy carbon electrochemical signal was obtained with a supporting electrolyte containing 40% methanol–25% acetonitrile–35% phosphate buffer (pH 6.0) as the mobile phase. The method was applied for the determination of the four compounds in menstrual women and the urine of pregnant rabbits.

A Transmembrane Intracellular Estrogen Receptor Mediates Rapid Cell Signaling

The steroid hormone estrogen regulates many functionally unrelated processes in numerous tissues. Although it is traditionally thought to control transcriptional activation through the classical nuclear estrogen receptors, it also initiates many rapid nongenomic signaling events. We found that of all G protein-coupled receptors characterized to date, GPR30 is uniquely localized to the endoplasmic reticulum, where it specifically binds estrogen and fluorescent estrogen derivatives. Activating GPR30 by estrogen resulted in intracellular calcium mobilization and synthesis of phosphatidylinositol 3,4,5-trisphosphate in the nucleus. Thus, GPR30 represents an intracellular transmembrane estrogen receptor that may contribute to normal estrogen physiology as well as pathophysiology.

Synthesis and Estrogenic Activity Screening of Some 6,9-Disubstituted Estradiol Derivatives

Oxidation of estradiol dipropionate (1) with chromium(VI) oxide-3,5-dimethylpyrazole complex yielded 9α-hydroxy-6-oxoestra-1,3,5(10)-triene-3,17β-diyl dipropionate (2) and 6-oxoestra-1,3,5(10)-triene-3,17β-diyl dipropionate (3). Dehydration of compound 2 with phosphorus(V) oxide or acetic anhydride gave 6-oxoestra-1,3,5(10),9(11)-tetraene-3,17β-diyl dipropionate (5). Reduction of compounds 2 and 5 with sodium borohydride afforded 3,6β,9α-trihydroxyestra-1,3,5(10)-triene-17β-yl propionate (4) and 3,6β-dihydroxyestra-1,3,5(10),9(11)-tetraene-17β-yl propionate (6), respectively. The action of thionyl chloride on compound 2 yielded 6-hydroxyestra-1,3,5(10),6,8-pentaene-3,17β-diyl dipropionate (7). Biological tests in vivo of these compounds showed a moderate antiestrogenic activity of compound 4.

Semiempirical QSAR study and ligand receptor interaction of estrogens

Softness values E(n)+/+ of estrogen derivatives and softness values E(m)+/+ of receptor lysine, histidine, tyrosine and cysteine have been evaluated by Klopman equation. The required parameters for the solution of Klopman equation have been calculated with the help of PM3 method. The difference deltaE(nm)+/+ between E(n)+/+ and E(m)+/+ has been derived for QSAR study. The estrogen derivatives have been divided into four different sets on the basis of their structural similarities, and their biological activity taken from literature in terms of relative binding affinity (RBA). The QSAR study shows that, deltaE(nm)+/+ values provide good relationship with biological activity.

Retention behaviour of estradiol derivatives in reversed phase HPLC

Retention behaviour ofestradiol derivatives has been studied by the reversed phase HPLC. LiChrosorb RP-18 column end eluents consisting of methanol respectively aceto-nitrile and water in various proportions, were used. It was shown that there is a linear relationship between the retention constant and the volume fraction of organic component in the mobile phase. The slopes and intercepts of lines are in agreement with the polarity of derivatives studied. Considerable effect on the chromatographic behaviour exerted the type and position of substituents in the molecule of estradiol derivative. Results obtained in these investigations are compared with results of the same derivatives obtained in previous investigations on octadecyl silica gel in TLC with eluent methanol-water in various proportions.

QSAR study of estrogens with the help of PM3‐based descriptors

AbstractQuantum chemical descriptors (ϵHOMO, ϵLUMO, absolute hardness, global softness, chemical potential, and electronegativity) and energy descriptors (Qmin, ΔH, ET, and EE) based QSAR study of estrogen derivatives was made with the help of PM3 calculations on WinMOPAC 7.21 software. The observed RBA values of estrogens were taken from the literature. QSAR models were made using different quantum chemical and energy descriptors with the help of multiple linear regression analysis. Regression models indicate that absolute hardness in combination with different energy descriptors provide better correlation between observed relative binding affinity (RBA) and predicted relative binding affinity (PA). Regression models for other quantum chemical descriptors with energy descriptors are not as clear as in the case of absolute hardness. Hardness provides a better picture due to the maximum hardness principle and can be used as a QSAR model for predicting the biological activity of any compound. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005

Gender as a Prognostic Factor in CLL. Biological Pointers to the Improved Outcome of Women.

Gender is not widely regarded as a prognostic indicator in CLL. However, the combined data from three MRC randomised trials, CLL1, 2 and 3, and two observational studies for patients with Binet stage A, CLL2A and 3A, over a period of 20 years (1978-1998) totalling 2370 patients, showed a significant survival advantage for women (2p<0.0001). Cox regression analysis of the three randomised trials showed that gender, age, stage and response to therapy were independent prognostic variables. The response to treatment for women was also better than for men receiving the same therapies. The LRF CLL4 randomised trial, which started in 1999 shows the same trend. Preliminary results in 444 patients Binet stages A progressive, B and C showed the same CR/Nod.PR for both sexes (43.5%) but a higher PR rate in women (45%) vs men (36.5%) and a lower proportion of women non-responders to first line therapy (11.5% vs 20%). A number of laboratory investigations in CLL4, which included FISH analysis with five probes, VH mutational status, CD38 and ZAP-70 expression by flow cytometry, showed differences between the sexes, which were significant for 17p and 11q deletions combined and CD38, always in favour of women, as shown in Tables 1 and 2.The clinical and laboratory results suggest that CLL is biologically more benign in women. Women have a lower incidence of CLL, an overall higher incidence of stage A (41.7%) than men (27.3%) in CLL 1, 2, 2A, 3 and 3A and respond better to treatment in all the trials. These differences may be underlined by a higher proportion of 13q del as sole abnormality, a lower proportion of 17p (p53 locus) and 11q deletions and lower levels of CD38. Data on VH mutations and ZAP-70 point in the same direction but the number of cases studied is still small. An additional factor that may play a role in the better outcome for women relates to the effect of oestrogen derivatives which are known to target selectively superoxide dismutase and induce cell kill (Huang et al, Nature 407, 390, 2000).Table 1: FISH analysis by gender (Dohner hierarchical model)Abnormality17p del11q delTrisomy 1213q delOthersMen (286)12%19%10%34%25%Women (94)7%13%11%44%25%p value**0.052* = Combined p value < 0.05 (Chi-Square test)Table 2: Other biological markersCD38 negative (<30%)VH mutatedZAP-70 negativeMen173/335 (52% )51/149 (34%)94/192 (49%)Women68/100 (68%)23/52 (44%)42/68 (62 %)p value<0.005NS0.07