Search

Cancer remains one of the leading causes of death, worldwide. In addition, the lack of efficacy and selectivity of chemotherapeutic agents for cancer cells is a challenge that needs to be addressed through the development of new drugs. Since aminosteroids are of interest in fighting cancer, our group previously reported antiproliferative activity on several cancer cell lines of two representatives, RM-133 and RM-581. To extend the structure-activity relationship study of aminosteroids, of which RM-133 (androstane) and RM-581 (estrane) are the main candidates, we performed the chemical synthesis and biological evaluation on lung (SHP-77), breast (T-47D) and prostate (DU-145, PC-3 and LAPC-4) cancer cells of four analogues of RM-581. We moved the functionalized side chain from position 2 of the androstane and estrane derivatives to incorporate it into a new chain located at position 17. Chemical synthesis took place in 2 steps from steroidal side-chain carboxylic acids, allowing to obtain 4 steroid derivatives with acceptable yields, which were fully characterized by nuclear magnetic resonance spectroscopy ( 1 H and 13 C NMR). After the evaluation of compounds 12-15, lower antiproliferative activities varying from 12 to 54%, 0-33% and 0-63% were observed for SHP-77, DU-145 and PC-3 cell lines, respectively, while higher activities varying from 33 to 62% and 45-84% were observed for T-47D and LAPC-4 cell lines, respectively, when tested at 10 µM. Overall, it was observed that these aminosteroids have a lower cytotoxic activity than that of RM-581 and, that moving the side chain from steroid position C2 to C17 is clearly detrimental for antiproliferative activity. However, this work has enabled us to expand our knowledge of the structural requirements to maintain the anticancer activity of aminosteroid derivatives., (Copyright © 2022 Elsevier Inc. All rights reserved.)

The total synthesis of (+)-03219A, a rare Δ 8,9 -pregnene isolated from the marine-derived Streptomyces sp. SCSIO 03219, is described that is based on a series of transformations that enable progression from epichlorohydrin to an ent -estrane, then conversion to a nat -androstane, and finally establishment of the natural product target. Key to the success of these studies was implementation of two rearrangement processes to formally invert the quaternary center at C13 and establish the C10 quaternary center.

The aminosteroid (AM) RM-581 is built around a mestranol backbone and has recently emerged as this family's lead candidate, showing in vitro and in vivo potency over different types of cancer, including high fatality pancreatic cancer. To extend the structure-activity relationships (SAR) to other estrane analogs, we synthesized a focused series of RM-581 derivatives at position C3 or C2 of its steroidal core. These new AM derivatives were first tested on a large selection of prostate, breast, pancreatic and ovarian cancer cell lines. The impact of these modifications on metabolic stability (human liver microsomes) was also measured. A SAR study revealed a fine regulation of anticancer activity related to the nature of the substituent. Indeed, the addition of potential prodrug groups like acetate, sulfamate or phosphate (compounds 8, 9 and 10) at C3 of the phenolic counterpart provided better antiproliferative activities than RM-581 in breast and pancreatic cancer cell types while maintaining activity in other cancer cell lines. Also, the phosphate group was highly beneficial on water solubility. However, the bulkier carbamate prodrugs 6 (N,N-dimethyl) and 7 (N,N-diethyl) were less active. Otherwise, carbon homologation (CH 2 ) at C2 (compound 33) was beneficial to metabolic stability and, in the meantime, this AM conserved the same anticancer activity as RM-581. However, the replacement of the hydroxy or methoxy at C3 by a hydrogen or an acetyl (compound 17 or 21b) was detrimental for anticancer activity, pointing to a crucial molecular interaction of the aromatic oxygen atom at this position. Overall, this work provided a better knowledge of the structural requirements to maintain RM-581's anticancer activity, and also identified minor structural modifications to increase both metabolic stability and water solubility, three important parameters of pharmacological development., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: RM, MP and DP have ownership interests on patent applications and patents related to this family of aminosteroid derivatives. JR declares no conflict of interest., (Copyright © 2019 Elsevier Masson SAS. All rights reserved.)

The high fatality and morbidity of pancreatic cancer have remained almost unchanged over the last decades and new clinical therapeutic tools are urgently needed. We determined the cytotoxic activity of aminosteroid derivatives RM-133 (androstane) and RM-581 (estrane) in three human pancreatic cancer cell lines (BxPC3, Hs766T and PANC-1). In PANC-1, a similar level of antiproliferative activity was observed for RM-581 and RM-133 (IC 50  = 3.9 and 4.3 μM, respectively), but RM-581 provided a higher selectivity index (SI = 12.8) for cancer cells over normal pancreatic cells than RM-133 (SI = 2.8). We also confirmed that RM-581 induces the same ER stress-apoptosis markers (BIP, CHOP and HERP) than RM-133 in PANC-1 cells, pointing out to a similar mechanism of action. Finally, these relevant in vitro results have been successfully translated in vivo by testing RM-581 using different doses (10-60 mg/kg/day) and modes of administration in PANC-1 xenograft models, which have led to tumor regression without any sign of toxicity in mice (animal weight, behavior and histology). Interestingly, RM-581 fully reduced the pancreatic tumor growth when administered orally in mice.

17β-Hydroxysteroid dehydrogenase type 1 (17β-HSD1) is a promising therapeutic target known to play a pivotal role in the progression of estrogen-dependent diseases such as breast cancer, and endometriosis. This enzyme is responsible for the last step in the biosynthesis of the most potent estrogen, estradiol (E2) and its inhibition would prevent the growth of estrogen-sensitive tumors. Based on molecular modeling with docking experiments, we identified two promising C3-oxiranyl/oxiranylmethyl-estrane derivatives that would bind competitively and irreversibly in the catalytic site of 17β-HSD1. They have been synthesized in a short and efficient route and their inhibitory activities over 17β-HSD1 have been assessed by an enzymatic assay. Compound 15, with an oxiranylmethyl group at position C3, was more likely to bind the catalytic site and showed an interesting, but weak, inhibitory activity with an IC 50 value of 1.3 µM (for the reduction of estrone into E2 in T-47D cells). Compound 11, with an oxiranyl at position C3, produced a lower inhibition rate, and the IC 50 value cannot be determined. When tested in estrogen-sensitive T-47D cells, both compounds were also slightly estrogenic, although much less than the estrogenic hormone E2., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Cytochrome P450 (CYP) 1B1 is involved in the bioactivation of procarcinogens and drug resistance. To obtain selective CYP1B1 inhibitors over CYP1A1, we synthesized four series of estrane derivatives: (1) 12 estrone (E1)- and 17β-estradiol (E2)-derivatives bearing a 3- or a 4-pyridinyl core at C2, C3, or C4, (2) eight estrane derivatives with different sulfur groups at C3, (3) 19 E1- and E2-derivatives bearing distinct aryls at C2, and (4) five D-ring derivatives. E2-derivatives were more active than oxidized E1-analogues, thus highlighting the key role of 17β-OH for interaction with CYP1B1. 2-(4-Fluorophenyl)-E2 was the best CYP1B1 inhibitor (IC 50 = 0.24 μM), with a selectivity index (SI) of 20 over CYP1A1. Furthermore, the addition of a C17α-ethynyl group as D-ring modification improved the selectivity index to 25 with only a slight loss of activity (IC 50 = 0.37 μM). Our docking results showed that these compounds fit better into the CYP1B1 binding site than that of CYP1A1.

The regioselective Cu(I)-catalyzed 1,3-dipolar cycloaddition of 3-methoxyestrane 17α- and 17β-azide epimers (3 and 5) with different terminal alkynes afforded novel 1,4-substituted triazolyl derivatives (8a-f and 11a-f). If the Ph3P in the classical CuAAC process was replaced by Et3N, the formation of small quantities of 5-iodotriazoles (9a-f and 11a-f) was observed. For the preparation of 5-iodo-1,2,3-triazoles (9a-f and 11a-f), an improved method was developed, directly from steroidal azides and terminal alkynes, in reactions mediated by CuI and ICl as iodinating agents. The antiproliferative activities of the structurally related triazoles were determined in vitro with the microculture tetrazolium assay on six malignant human cell lines of gynecological origin (HeLa, A2780, MCF7, MDA-MB-231, MDA-MB-361 and T47D). X-ray analysis revealed the presence of the iodo substituent on the 1,2,3-triazole ring., (Copyright © 2015 Elsevier Inc. All rights reserved.)

A simple, sensitive and low-cost method using CE coupled with glucose-β-CD interaction assisted ACN stacking technique has been developed for quantification of trace amlodipine in dog plasma. The plasma samples were extracted with methyl tert-butyl ether. The separation was performed at 25°C in a 31.2 cm × 75 μm fused-silica capillary with an applied voltage of 15 kV. The BGE was composed of 6.25 mM borate/25 mM phosphate (pH 2.5) and 5 mg/mL glucose-β-CD. The detection wavelength was 200 nm. Because CD could diminish the interaction between drugs and matrix, and derivation groups of CD play an important role in separation performance, the effects of β-CD, and its derivatives on the separation were studied at several concentrations (0, 2.5, 5.0, 10.0 mg/mL). In this study, organic solvent field-amplified sample stacking technique in combination with glucose-β-CD enhanced the sensitivity about 60-70 folds and glucose-β-CD could effectively improve the peak shape. All the validation data, such as accuracy, precision extraction recovery, and stability, were within the required limits. The calibration curve was linear for amlodipine from 1 to 200 ng/mL. The method developed was successfully applied to the pharmacokinetic studies of amlodipine besylate in beagle dogs., (© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A capillary chromatography system has been developed using a ternary mixed-solvents solution, i.e. water-hydrophilic/hydrophobic organic solvent mixture as a carrier solution. Here, we tried to carry out the chromatographic system on a microchip incorporating the open-tubular microchannels. A model analyte solution of isoluminol isothiocyanate (ILITC) and ILITC-labeled biomolecule was injected to the double T-junction part on the microchip. The analyte solution was delivered in the separation microchannel (40 μm deep, 100 μm wide, and 22 cm long) with the ternary water-ACN-ethyl acetate mixture carrier solution (3:8:4 volume ratio, the organic solvent rich or 15:3:2 volume ratio, the water-rich). The analyte, free-ILITC and labeled BSA mixture, was separated through the microchannel, where the carrier solvents were radially distributed in the separation channel generating inner and outer phases. The outer phase acts as a pseudo-stationary phase under laminar flow conditions in the system. The ILITC and the labeled BSA were eluted and detected with chemiluminescence reaction., (© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Ionic liquids 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim](+)[PF(6)](-)) and 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim](+)[BF(4)](-)) were found to promote an unusual Wagner-Meerwein rearrangement of steroidal 16α,17α-epoxides leading to unnatural 13-epi-18-nor-16-one derivatives as the main products. These compounds were isolated in good to excellent yields. 16α-Hydroxy-Δ(13)-18-norsteroids, the results of the usual rearrangement, were obtained as minor components of the reaction mixtures. The ionic liquid [bmim](+)[PF(6)](-) was shown to induce C-ring aromatization of 16α,17α-epoxyestranes due to the formation of HF, the hydrolysis product of [PF(6)](-). Increasing amounts of HF and [PO(2)F(2)](-) were detected by (19)F and (31)P NMR when the ionic liquid was reused. The structures of the steroidal products, 16-oxo-18-nor-13α-steroid derivatives, 16α-hydroxy-Δ(13)-18-norsteroids, and C-aromatic compounds were determined by two-dimensional NMR techniques and high-resolution mass spectrometry (HRMS). The ionic liquids were recirculated efficiently.

Nandrolone (19-nortestosterone) is an androgenic anabolic steroid illegally used as a growth-promoting agent in animal breeding and as a performance enhancer in athletics. Therefore, its use was officially banned in 1974 by the Medical Commission of the International Olympic Committee (IOC). Following nandrolone administration, the main metabolites in humans are 19-norandrosterone, 19-norethiocolanolone and 19-norepiandrosterone, and their presence in urine is the basis of detecting its abuse. The present work was undertaken to determine, in human urine, nandrolone metabolites (phase I and phase II) by developing and comparing multiresidue liquid chromatography/tandem mass spectrometry (LC/MS/MS) and gas chromatography/mass spectrometry (GC/MS) methods. A double extraction by solid-phase extraction (SPE) was necessary for the complete elimination of the interfering compounds. The proposed methods were also tested on a real positive sample, and they allow us to determine the conjugated/free fractions ratio reducing the risk of false positive or misleading results and they should allow laboratories involved in doping control analysis to monitor the illegal use of steroids. The advantages of LC/MS/MS over GC/MS (which is the technique mainly used) include the elimination of the hydrolysis and derivatization steps: it is known that during enzymatic hydrolysis several steroids can be converted into related compounds and deconjugation is not always 100% effective. The validation parameters for the two methods were similar (limit of quantification (LOQ) <1 ng/mL and percentage coefficient of variance (CV%) <16.4), and both were able to confirm unambiguously all the analytes, thus confirming the validity of both techniques., (Copyright 2010 John Wiley & Sons, Ltd.)

A simple and complete multiresidue method has been developed for the routine determination of 236 pesticides and degradation products, in meat based baby-food. This original approach combines a modified Quick Easy Cheap Effective Rugged and Safe (QuEChERS) sample preparation method using a triple partitioning extraction step with water/ACN/hexane and a system composed of GC with programmable temperature vaporization injector hyphenated to an IT-MS. Detection was performed in full scan mode, with one quantification ion and one identification ion. We firstly report here the hexane addition in the extraction step to eliminate a major part of lipophile co-extracts. Direct consequences were the increasing of method sensitivity and the diminishment of the frequency of maintenance of the analytical instrument. The recovery data were obtained by spiking blank samples at three concentration levels (10, 50 and 200 microg/kg) over five replicates, yielding average recoveries in the range 70-121% with a RSD evaluated between 2-15%. Linearity was fixed in the range of 10-300 microg/kg with determination coefficients (R2) superior or equal to 0.9814 for all target analytes. Best LODs and LOQs were established as 0.03 and 0.1 microg/kg, respectively. Total instrumental analysis of all molecules was carried out in less than 1 h.

CZE was assayed for the separation of carbamate pesticides susceptible to protonation (Pirimicarb, Carbendazim). Different electrophoretic media with high organic contents were explored, adequate separation and resolution being achieved when a BGE based on ACN with acetic acid in the presence of SDS as an ionic additive was used. With a view to increasing the sensitivity of the method, an in-capillary SPE step prior to the electrophoretic separation was developed. We employed a monolithic polymer formed in situ within the capillary as a medium for analyte retention. The synthesized monolithic bed exhibited high porosity and allowed samples to be loaded at flow rates of about 65 microL/min by applying a pressure of 12 bar. A 5-cm length of monolithic sorbent was used to preconcentrate the target analytes from aqueous samples. The analytes retained were eluted from the polymeric phase directly in the separation capillary with the same electrophoretic medium used for their further separation by CZE. For a 15-min preconcentration time, the in-line SPE-CZE approach proposed here permitted the determination of these pesticides in drinking water at a concentration level of 0.1 microg/L, as demanded by current EU legislation.

ACN is an extremely poor hydrogen bond donor and therefore the anions dissolved in it are solvated mainly by other hydrogen bond donors (e.g. uncharged acids) possibly present in the solution. Under properly selected experimental conditions stabilization via hydrogen bonding can be used for separation in CE as has been demonstrated for uncharged acids by several authors. Electromigration based on heteroconjugation can be of importance, e.g. when aqueous separation medium cannot be used due to stability reasons. It also allows CE to be used as a tool for solution chemistry measurements, if the required physicochemical properties of the studied system are known or they can be predicted with sufficient accuracy by existing theories. In the present work we showed that also an uncharged base can stabilize an anion via hydrogen bonding in ACN. In the setup imidazole was chosen as a model base and acetate ion as complexing anion in equimolar acetic acid-acetate buffer. The resulted hydrogen-bonded imidazole-acetate complex (i.e. heteroconjugate) possesses a charge and can thus migrate in CE. It was shown that the studied complexation in ACN is sensitive to competition by other hydrogen bond donors such as water and methanol. On the other hand, acetone, which is a poor hydrogen bond donor, did not have much effect on the complexation. To take the effect of ionic strength on mobility into account, mobilities of the imidazole-acetate complex measured at various ionic strengths were corrected to zero ionic strength by the aid of conductivity equation. A fit of the 1:1 binding isotherm to the ionic strength corrected mobility versus acetate concentration data led to rather good correlation. However, x-reciprocal linear transformation of the binding isotherm showed nonlinearity, which could be partly explained by homoconjugation of acetic acid and acetate ion. Since the homoconjugation constant for acetic acid under present experimental conditions was not available, theoretical simulations were used to demonstrate the effects of homoconjugation. The possibility of multiple complexation of imidazole was discussed as well.

N,N'-Alkylmethylimidazolium cations have been separated in NACE when one of the N,N'-dialkylimidazolium salts (ionic liquids (ILs)) was used as an electrolyte additive to the organic solvent separation medium. The separated species were 1-methyl-, 1-ethyl-, 1-butyl-, 1-octyl-, 1-decyl-3-methylimidazolium and N-butyl-3-methylpyridinium cations and BGE composed of 1-ethyl-3-methylimidazolium ethylsulfate or 1-butyl-3-methylimidazolium trifluoroacetate [BMIm][FAcO] (A6; B2) diluted in ACN. It was demonstrated that contactless conductivity detection (CCD) may be applied to monitoring the separation process in nonaqueous separation media, allowing to use the UV light-absorbing imidazolium-based electrolyte additives. There could be marked three concentration regions of added ILs; at first ionic strength of BGE below 1-2 mM, and then the actual electrophoretic mobility of analytes rises from 0. At concentrations above 1-2 mM, the added IL facilitated separation. In concentration region of 1-20 mM, the actual electrophoretic mobility of analyzed imidazolium cations was increasing with decrease in separation medium ionic strength. At higher concentrations of BGE (above 30 mM), the conductivity of the separation media became too high for this detector. Some organic dyes were also successfully separated and detected by contactless conductivity detector in a 20 mM A6 separation electrolyte in ACN.

tert-Butyl hydroperoxide catalyzed by (5,10,15,20-tetramesitylporphyrinate) osmium(II) carbonyl [Os(TMP)CO] complex was found to be a highly efficient versatile oxidant for C-H carbons in steroid substrates. When reacted with representative steroids with an estrane, pregnane, 5beta-cholane, or 5alpha-cholestane structure, regioselective oxyfunctionalization and/or oxidative degradation occurred to give a variety of novel and uncommon derivatives in one step.

A new sample pretreatment approach in CE was developed for concurrent biological sample clean-up and the concentration of hydrophobic compounds based on the combination of ACN deproteinization with salting-out extraction. Further enhancement in concentration detection sensitivity was achieved by coupling (offline) salting-out extraction with an online CE sample enrichment technique known as "ACN stacking". By optimizing the pH of salting-out extraction, a number of model compounds (hydrophobic porphyrins with clinical significances), i.e. zinc-protoporphyrin, protoporphyrin, and coproporphyrin (CP) III and I, can be efficiently extracted from the aqueous sample into a smaller volume organic solvent (ACN) phase and an enrichment factor of ca. 100 can be obtained. The pressure injection of the enriched ACN phase (containing ca.1% NaCl) into the CE capillary at 10% capillary volume resulted in additional concentration of the various hydrophobic porphyrins, allowing for a combined enrichment factor of ca.1000 to be obtained. Calibration curves obtained for the determination of a pair of positional isomers with significant diagnostic value, urinary CPIII and CPI, were found to be linear between 10-300 ng/mL (with R2 = 0.999), and LODs (absorbance detection at 400 nm) were ca. 0.8 ng/mL (1.1 nmol/L of CPIII or CPI). Based on a single salting-out extraction, intraday precisions (nine consecutive injections) for both CPIII and CPI (at spiked concentrations of 10-300 ng/mL into urine) in terms of migration time and peak area were found to be within the range of 0.2-0.5 and 0.8-2.9%, respectively.

19-Norandrosterone (19-NA) is the major metabolite of the steroid nandrolone, one of the most commonly abused anabolic androgenic agents. 19-NA exists mainly as the glucuronide form in human urine. A candidate reference measurement procedure for 19-NA in urine involving isotope dilution coupled with liquid chromatography/tandem mass spectrometry (LC/MS/MS) has been developed and critically evaluated. The 19-NA glucuronide was enzymatically hydrolyzed, and the 19-NA along with its internal standard (deuterated 19-NA) was extracted from urine using liquid-liquid extraction prior to reversed-phase LC/MS/MS. The accuracy of the measurement of 19-NA was evaluated by a recovery study of added 19-NA. The recovery of the added 19-NA ranged from 99.1 to 101.4%. This method was applied to the determination of 19-NA in urine samples fortified with 19-NA glucuronide at three different concentrations (equivalent to 1, 2, and 10 ng/mL 19-NA). Excellent reproducibility was obtained with within-set coefficients of variation (CVs) ranging from 0.2 to 1.2%, and between-set CVs ranging from 0.1 to 0.5%. Excellent linearity was also obtained with correlation coefficients of all linear regression lines (measured intensity ratios vs mass ratios) ranging from 0.9997 to 0.9999. The detection limit for 19-NA at a signal-to-noise ratio of approximately 3 was 16 pg. The mean results of 19-NA yielded from hydrolysis of 19-NA glucuronide compared well with the theoretical values (calculated from the conversion of 19-NA glucuronide to 19-NA) with absolute relative differences ranging from 0.2 to 1.4%. This candidate reference measurement procedure for 19-NA in urine, which demonstrates good accuracy and precision and low susceptibility to interferences, can be used to provide an accuracy base to which routine methods for 19-NA can be compared and that will serve as a standard of higher order for measurement traceability.

The preparation of estrone derived benzothieno- and benzofurano fused steroids is described. Keystep is an intramolecular thienyl(/furyl)-ene-yne cyclization of 16-ethynyl-17-heterarylestra-1,3,5(10),16-tetraenes. The cyclization was carried out under Pt as well as under Ru catalysis.

Neurosteroids are potent blockers of neuronal low-voltage activated (T-type) Ca(2+) channels and potentiators of GABA(A) ligand-gated channels, but their effects in peripheral pain pathways have not been studied previously. To investigate potential analgesic effects and the ion channels involved, we tested the ability of locally injected 5alpha-reduced neurosteroids to modulate peripheral thermal nociception to radiant heat in adult rats in vivo and to modulate GABA(A) and T-type Ca(2+) channels in vitro. The steroid anesthetic alphaxalone (ALPX), the endogenous neurosteroid allopregnanolone (3alpha5alphaP), and a related compound ((3alpha,5alpha,17beta)-3-hydroxyandrostane-17-carbonitrile, (ACN)), induced potent, dose-dependent, enantioselective anti-nociception in vivo and modulation of both T-type Ca(2+) currents and GABA(A)-mediated currents in vitro. Analgesic effects of ALPX were incompletely antagonized by co-injections of the GABA(A) receptor antagonist bicuculline. The neurosteroid analogue ((3alpha,5alpha)-3-hydroxy-13,24-cyclo-18,21-dinorchol-22-en-24-ol (CDNC24), a compound with GABAergic but not T-type activity, was not analgesic. However, (3beta,5alpha,17beta)-17-hydroxyestrane-3-carbonitrile (ECN)), which has effects on T-type channels but not on GABA(A) receptors, also induced potent enantioselective peripheral anti-nociception. ECN increased pain thresholds less than ALPX, 3alpha5alphaP and ACN. However, when an ineffective dose of CDNC24 was combined with ECN, anti-nociceptive activity was greatly enhanced, and this effect was bicuculline-sensitive. These results strongly suggest that GABA(A) channels do not contribute to baseline pain transmission, but they can enhance anti-nociception mediated by blockade of T-type Ca(2+) channels. In conclusion, we demonstrate that potent peripheral analgesia induced by 5alpha-reduced neurosteroid is mediated in part by effects on T-type Ca(2+) channels. Our results also reveal a role of GABA-gated ion channels in peripheral nociceptive signaling.

The combined use of different mass spectrometric ionization methods and MS/MS techniques provide the possibility to differentiate between stereoisomers or epimers. In this paper the mass spectral decomposition of 11alpha- and 11beta-substituted estrans was studied. Distinctive stereochemical effects have been observed in their fast atom bombardment product ion spectra. In the electron ionisation (EI) mode, the 5alpha- and 5beta-hydroxylated compounds showed significant differences in the abundance of water elimination. Mass spectrometry has proved to be an effective tool when stereoisomer steroids are compared.

The title compound, C21H24FN2O2+.Cl-.C3H8O, is a potential drug designed as a hybrid compound with antihypertensive, antioxidant and beta-adrenolytic activity. The cation contains nearly planar benzofuran and fluorophenyl ring systems, as well as a piperazine ring adopting an almost perfect chair conformation. The benzofuran and piperazine moieties are connected by an ethyl chain, the moieties forming a dihedral angle of 163.12 (13) degrees. In the crystal structure, ions and propanol solvent molecules are linked via N-H...Cl and O-H...Cl bonds into linear (010) chains.

In the title compound, C21H25N3O, the six-membered ring that is fused to two other six-membered rings in the estrane moiety adopts an envelope conformation. The compound shows intermolecular hydrogen bonding of the amine group to an N atom of the pyrimidine moiety, as well as weak intermolecular interactions involving H atoms in the hydrophobic residue of the molecule.

In the title compound, C(24)H(31)NO(2), ring B adopts a conformation between the boat and twisted-boat forms. This conformation best accommodates adverse intramolecular H.H interactions between the H atoms of the 7beta-substituent and the two nearest ring H atoms. The tilt angle between rings A and D is 28.6 (1) degrees.

The preparation of a steroidal heterocycle linked to the tripeptide Cys-Gly-Cys is described. Initially, an estrane-derived steroidal heterocycle containing an aminopyrimidine ring fused to the 16,17-position of the steroidal nucleus was synthesized. Thereafter, protected amino acids were coupled iteratively by the DCC method, commencing at the amino group of the aminopyrimidine unit.

D-Homo derivatives in the androstane and estrane series, 12-19, were synthesized by a fragmentation-cyclization reaction of 16-oximino-17-hydroxy-17-substituted derivatives 3-9, or by cyclization of the corresponding D-seco derivatives 20-26. The structures were confirmed by X-ray analysis of compounds 12 and 16. Preliminary assessment of inhibitory effects of D-homo derivatives from androstane series towards aromatase, 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD), 17 alpha-hydroxylase/C17-20 lyase (P450c17) and 17 beta-HSD indicated much lower inhibitory potential compared to previously tested activity of another type of D-modified steroids, namely D-seco derivatives. Also, assessment of potential antiestrogenic activity of derivatives from estrane series showed absence of such an activity.

The retention constants (RM) of a series of estrane and secoestrane derivatives are experimentally determined on C18-modified silica gel layers with methanol-water mobile phases of various concentrations. The slopes (m) and intercepts (RMW) of the linear relationships between RM and the volume fraction of methanol are calculated. Both constants increase when the retention of compounds increases, and there is a linear dependence between them indicating their additivity; they represent the sums of particular retention contributions of skeleton and substituents. The contributions, particularly the retention fragmental constants, are calculated by combining the linear relationships RM/log P, RM/m, and RMW/log P. The log P values of the compounds and skeleton were calculated using Rekker's fragmental constants.

The article reviews the progress in the chemistry of the steroids that was published between January and December, 2000. The reactions and partial syntheses of estrogens, androgens, pregnanes, cholic acid derivatives, cholestanes and vitamin D analogues are covered. There are 169 references.

Progestogens are commonly used in hormone replacement therapy, normally as opponents of estrogen to protect the endometrium from hyperplasia and cancer. While these benefits of endometrial protection are well recognized, the data related to the effect of progestogens on breast tissue and the cardiovascular system are conflicting. It has been demonstrated that, according to the type of progestogen used, and the dose and duration of its application, a predominant proliferative effect may be observed in human breast cells. As far as breast cancer is concerned, most epidemiological studies suggest no difference in risk between therapy with estrogens alone or estrogens combined with progestogens, but recent data do indicate an increased risk with combined therapy. When the cardiovascular risk factors are considered, some progestogen molecules with a higher androgenic potency than others attenuate the beneficial effects of estrogens on both the lipid profile and vasomotion. On the other hand, the epidemiological data on primary prevention do not suggest any negative effect of the progestogens administered together with estrogens on cardiovascular morbidity or mortality. Recent results have questioned the cardioprotective effect of hormone replacement therapy in women with established coronary heart disease. It has been suggested that the lack of a secondary preventive effect by hormone replacement therapy may be due to the progestogens selected. The effect on osteoporosis is also the subject of debate, with some progestogens having a neutral effect on bone mineral density and others producing a marked improvement. Awareness of the classic contraindications of hormone replacement therapy and selection of molecules devoid of estrogenic, androgenic or glucocorticoid effect should allow greater use of the progestogens without any major drawback.

Steroids, in addition to regulating gene expression, directly affect a variety of ion channels. We examined the action of steroids on human embryonic kidney 293 cells stably transfected to express rat alpha4beta2 neuronal nicotinic receptors. Each steroid that was tested inhibited acetylcholine responses from these receptors, with slow kinetics requiring seconds for block to develop and recover. The action of one steroid [3alpha,5alpha, 17beta-3-hydroxyandrostane-17-carbonitrile (ACN)] was studied in detail. Block showed enantioselectivity, with an IC(50) value of 1.5 microM for ACN and 4.5 microM for the enantiomer. Inhibition curves had Hill slopes larger than 1, indicating more than one binding site per receptor. Block did not require intracellular compounds containing high-energy phosphate bonds and was not affected by analogs of GTP, suggesting that the mechanism does not require the activation of second messengers. Block did not appear to be strongly selective between open and closed channel states or to involve changes in desensitization. A comparison of different steroids showed that a beta-orientation of groups at the 17 position produced more block than alpha-orientated diastereomers. The stereochemistry at the 3 and 5 positions was less influential for block of alpha4beta2 nicotinic receptors, despite its importance for potentiation of gamma-aminobutyric acid(A) receptors. The ability of steroids to block neuronal nicotinic receptors correlated with their ability to produce anesthesia in Xenopus tadpoles, but the concentrations required for inhibition are generally greater. Similarly, the concentrations of endogenous neurosteroids required to inhibit receptors are larger than estimates of brain concentrations.

Reaction of 3,9 alpha, 17 beta-trihydroxyestra-1,3,5(10)-trien-11-one 17-acetate 3-methyl ether (3) with N3H-BF3 etherate leads mainly to lactam (4) along with the N-azido compound (5) as a minor product. Under similar conditions, 3,17 beta-dihydroxyestra-1,3,5(10)-trien-6-one 17-acetate 3-methyl ether gives lactam (12) and the tetrazole derivative (9). Similar reaction of the diacetate (8) gives only the tetrazole derivative (11). Compounds 4, 6, and 10 prevent implantation in rats at 5-, 10-, and 5-mg/kg doses, respectively. Compounds 4, 6, 9, and 10 show significant estrogenic activity at the respective contraceptive doses.