Direct quantification of anorethidrani disuccinate and determination of sterol metabolites by chemical derivatization combined with LC-MS/MS: Application to a Phase I pharmacokinetic study in humans.

Anorethidrani disuccinate (ACP) is a domestically designed A-decarbonized steroid that is currently being investigated in Phase I clinical trials for the treatment of solid tumors. Only the parent drug exhibited antitumor activity; its sterol metabolite M2 showed obvious antiestrogenic effects. We have developed a rapid, sensitive, and robust liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the direct quantification of ACP and a chemical derivatization method that can be used to quantify M2 derivatized with glycidyl trimethyl ammonium chloride (GTMA). A simple protein precipitation procedure was performed to quantify ACP. Injections were obtained within 3.5 min on an Eclipse Plus Phenyl-Hexyl column (50 mm × 2.1 mm i.d., 1.8 µm) with gradient elution; the calibration curve was linear over the range of 2.00-8000 ng/mL. For quantification of M2 in plasma, analytes were extracted by protein precipitation and converted to their GTMA derivatives at 60 °C for 2 h at pH 12; the analytes and coelutants were separated on a Luna C8(2) column (50 mm × 2.0 mm i.d., 5.0 µm). The precision (RSD) and accuracy (RE) of the intra- and interday determinations were within 10%. The derivatization procedure is a novel method for sterol determination by LC-MS/MS. The results confirmed the usefulness of this method for characterizing the pharmacokinetic profiles of ACP and its major metabolite M2 in a Phase I pharmacokinetic study.

The synthesis of 4-chloro-17ß-hydroxymethyl-17α-methyl-18-norandrosta-4,13-diene-3α-ol - Proposed long term metabolite (M4) of oralturinabol.

4-Chloro-17ß-hydroxymethyl-17α-methyl-18-norandrosta-4,13-diene-3α-ol is one of proposed long term metabolites of oralturinabol (anabolic androgenic steroid restricted in sport). The synthesis of 4-chloro-17ß-hydroxymethyl-17α-methyl-18-norandrosta-4,13-diene-3α-ol was achieved. Isomerisation of configuration of 13-carbon was used for construction of 17ß-hydroxymethyl-17α-methyl fragment. The proposed route of synthesis allows to obtain 3ß-hydroxy isomer as well.

Predominant contributions of carboxylesterase 1 and 2 in hydrolysis of anordrin in humans.

1. Anordrin (2α, 17α-diethynyl-A-nor-5α-androstane-2ß, 17ß-diol diproprionate) is post-coital contraceptive drug that is on the market in China for more than 30 years. This study aims to elucidate enzymes involved in anordrin hydrolysis, and to evaluate the significant role of carboxylesterases in anordrin hydrolysis in humans. 2. Human liver and intestinal microsomes, recombinant human carboxylesterase were selected as enzyme sources. In human liver microsomes, intrinsic clearance was 684 ± 83 µL/min/mg protein, which was considerably higher than the value of intestine microsomes (94.6 ± 13.3 µL/min/mg protein). Carboxylesterase (CES) 1 has more contribution than CES2 in human liver. 3. Inhibition studies were performed using representative esterase inhibitors to confirm esterase isoforms involved in anordrin hydrolysis. Simvastatin strongly inhibited hydrolytic process of anordrin in liver and intestine microsomes, with IC50 values of 10.9 ± 0.1 and 6.94 ± 0.03 µM, respectively. 4. The present study investigated for the first time hydrolytic enzyme phenotypes of anordrin. Anordrin is predominantly catalyzed by CES1 and CES2 to generate the main active metabolite, anordiol. Moreover, anordrin and its metabolite anordiol can be altered by esterase inhibitors, such as simvastatin, upon exposure in vivo.

C-H Acetoxylation-Based Chemical Synthesis of 17 ß-Hydroxymethyl-17 α-methyl-18-norandrost-13-ene Steroids.

Palladium-catalyzed C-H acetoxylation has been proposed as a key transformation in the first chemical synthesis of steroids bearing a unique 17ß-hydroxymethyl-17α-methyl-18-nor-13-ene D-fragment. This C-H functionalization step was crucial for inverting the configuration at the quaternary stereocenter of a readily available synthetic intermediate. The developed approach was applied to prepare the metandienone metabolite needed as a reference substance in anti-doping analysis to control the abuse of this androgenic anabolic steroid.

Synthesis of novel 13α-18-norandrostane-ferrocene conjugates via homogeneous catalytic methods and their investigation on TRPV1 receptor activation.

13α-Steroid-ferrocene derivatives were synthesized via two reaction pathways starting from an unnatural 16-keto-18-nor-13α-steroid. The unnatural steroid was converted to ferrocene derivatives via copper-catalyzed azide-alkyne cycloaddition or palladium-catalyzed aminocarbonylation. 16-Azido- and 16-N-(prop-2-ynyl)-carboxamido-steroids were synthesized as starting materials for azide-alkyne cycloaddition with the appropriate ferrocene derivatives. Based on our earlier work, aminocarbonylation of 16-iodo-16-ene and 16-iodo-15-ene derivatives was studied with ferrocenylmethylamine. The new products were obtained in moderate to good yields and were characterized by (1)H and (13)C NMR, IR and MS. The solid state structure of the starting material 13α-18-norandrostan-16-one and two carboxamide products were determined by X-ray crystallography. Evidences were provided that the N-propargyl-carboxamide compound as well as its ferrocenylmethyltriazole derivative are able to decrease the activation of TRPV1 receptor on TRG neurons.

Hydrogen bonding between the 17beta-substituent of a neurosteroid and the GABA(A) receptor is not obligatory for channel potentiation.

BACKGROUND AND PURPOSE: Potentiating neurosteroids are some of the most efficacious modulators of the mammalian GABA(A) receptor. One of the crucial interactions may be between the C20 ketone group (D-ring substituent at C17) of the neurosteroid, and the N407 and Y410 residues in the M4 domain of the receptor. In this study, we examined the contribution of hydrogen bonding between 17beta-substituents on the steroid D-ring and the GABA(A) receptor to potentiation by neurosteroids. EXPERIMENTAL APPROACH: Whole-cell and single-channel recordings were made from HEK 293 cells transiently expressing wild-type and mutant alpha1beta2gamma2L GABA(A) receptors. KEY RESULTS: A steroid with a 17beta-carbonitrile group (3alpha5alpha18nor17betaCN) was a potent and efficacious potentiator of the GABA(A) receptor. Potentiation was also shown by a cyclosteroid in which C21 and the C18 methyl group of (3alpha,5alpha)-3-hydroxypregnan-20-one are connected within a six-membered ring containing a double bond as a hydrogen bond acceptor (3alpha5alphaCDNC12), a steroid containing a 17beta-ethyl group on the D-ring (3alpha5alpha17betaEt) and a steroid lacking a 17beta-substituent on the D-ring (3alpha5alpha17H). Single-channel kinetic analysis indicates that the kinetic mechanism of action is the same for the neurosteroid 3alpha5alphaP, 3alpha5alpha18nor17betaCN, 3alpha5alphaCDNC12, 3alpha5alpha17betaEt and 3alpha5alpha17H. Interestingly, 3alpha5alpha17betaEt, at up to 3 microM, was incapable of potentiating the alpha1N407A/Y410F double mutant receptor. CONCLUSIONS AND IMPLICATIONS: Hydrogen bonding between the steroid 17beta-substituent and the GABA(A) receptor is not a critical requirement for channel potentiation. The alpha1N407/Y410 residues are important for neurosteroid potentiation for reasons other than hydrogen bonding between steroid and receptor.

16-Cyano-13alpha-(5-methyl-1,3,4-oxadiazol-2-yl)-13,16-seco-17-norandrost-5-en-3beta-yl acetate.

In the title compound, C(23)H(31)N(3)O(3), the outer cyclohexane rings have chair conformations, while the central cyclohexene ring adopts a half-chair conformation. In the solid state, intra- and intermolecular C-H.N interactions are observed.

[The absolute configurations and biological activities of alpha- and beta-anordrins].

The molecular structures and absolute configurations of alpha- and beta-anordrins are reported. Animal experiments showed that pure alpha-epimer possessed high anti-implantation and anti-early pregnancy effects, but the pure beta-epimer exhibited very low effects at the same dose. MNDO program was applied for the optimization of the configurations of epimers to establish the isolated molecular configurations and calculate the quantum chemical indexes. The results showed that the configurations and the differences of action field in three-dimensions of alpha- and beta-epimer are probably the factors that the alpha-epimer exhibited biological activity.

Synthesis of C-6 fluoroandrogens: evaluation of ligands for tumor receptor imaging.

Seven androgens, substituted with fluorine at C-6, were prepared as potential imaging agents for androgen receptor-positive prostate tumors and were evaluated in vitro in terms of their lipophilicity and their relative binding affinities (RBA, relative to R 1881 = 100) for the androgen receptor and for sex steroid binding protein. Introduction of a fluorine atom into the C-6 position of an androgen generally decreases binding affinity to the androgen receptor, except in the two cases: 6 alpha-fluoro-19-nor-testosterone (RBA = 41.6 versus 30.6 for the unsubstituted steroid) and 6 alpha-fluorotestosterone (RBA = 8.9 versus 6.6). Receptor binding of the C-6 fluoro-androgens is also stereospecific, showing higher binding affinities for the alpha-epimers compared to the corresponding beta-epimers (4:1-15:1). Binding affinity to sex steroid binding protein is the lowest with 19-nor-testosterone, which is also the least lipophilic androgen studied. Based on the binding properties of compounds in this series, 6 alpha-fluoro-19-nor-testosterone appears to have the most promise as a tumor imaging agent.

Developing a radioimmunoassay for anordrin: the synthesis of propionyl and hemisuccinyl esters of anordiol.

We describe the chemical synthesis of the 2 beta-propionate-17 beta- hemisuccinate and 2 beta-hemisuccinate-17 beta-propionate diesters of anordiol (2 alpha,17 alpha-diethynyl-A-nor-5 alpha-androstane-2 beta,17 beta-diol) and the method for coupling them to bovine serum albumin and Affi-gel 102, in order to prepare antibodies for radioimmunoassay of anordrin. In addition, we describe the chemical synthesis of the following derivatives: 2 beta-ol-17 beta-propionate, 2 beta-propionate-17 beta-ol, 2 beta-hemisuccinate-17 beta-ol, and 2 beta-ol-17 beta-hemisuccinate.

X-ray diffraction studies on the absolute configuration of alpha- and beta-anordrins.

The molecular structures and absolute configurations of alpha- and beta-anordrins are reported. Pure alpha- and beta-epimers were obtained with recrystallization and column chromatography combined with high-pressure liquid chromatography methods; they were identified by high-resolution infrared and mass spectra and 1H and 13C nuclear magnetic resonance. By single crystal x-ray diffraction analysis, the crystals of alpha- and beta-epimers were found to belong to the orthorhombic space groups P2(1)2(1)2(1) and P2(1)2(1)2, respectively. The molecular structures of these two epimers were determined. The absolute configurations were deduced by conformation analysis, 1H nuclear magnetic resonance, and comparison with the absolute configuration of the starting material. The absolute configurations of asymmetric centers of alpha- and beta-epimers were observed to be 2R, 5S, 8R, 9S, 10S, 13S, 14S, 17R, and 2S, 5S, 8R, 9S, 10S, 13S, 14S, 17R, respectively. These results were confirmed by the x-ray diffraction determination of the absolute configuration of 2 alpha,17 alpha-diethynyl-A-nor-5 alpha- androstane-2 beta, 17 beta-diol dichloroacetate.

[X-ray diffraction studies on the configuration of 2 xi, 17 alpha-diethynyl-2 xi, 17 beta-dihydroxy-A-nor-5 alpha-androstane alpha-epimer].

X-ray diffraction studies on the configuration of 2 xi, 17 alpha-diethynyl-2 xi, 17 beta-dihydroxy-A-nor-5 alpha-androstane "alpha-epimer" that possessed antifertility effect and estrogen activity were reported. Pure alpha-epimer was obtained by recrystallization and low pressure silica gel column chromatography combined with HPLC method. Its structure was identified by IR, MS, 1HNMR. The configuration was determined by single crystal X-ray diffraction analysis. The crystal of alpha-epimer belonged to orthorhombic, the space group was P222(1), with the following crystallographic parameters: a = 6.777 (2), b = 12.125 (4), c = 25.292 (8)A, V = 2078.5(1.2)A3, Z = 4. One thousand two hundred and thirty-five independent reflections with I greater than or equal to 3 sigma (I) were collected on a Nicolet R3M/E four-circle diffractometer by means of MoK alpha radiation. The structure was solved by direct method and refined by least square technique to a final discrepancy factor of R = 0.039. The molecule was shown to consist of the alpha-configuration of C2 and C17ethynyl groups. The absolute configuration was deduced by the absolute configuration of synthetic raw material, conformation analysis and the study of 1HNMR. The absolute configuration of asymmetric centers were 2R,5S,8R,9S,10S,13S,14S,17R.