Innovative C2-symmetric testosterone and androstenedione dimers: Design, synthesis, biological evaluation on prostate cancer cell lines and binding study to recombinant CYP3A4.

The synthesis of two isomeric testosterone dimers and an androstenedione dimer is reported. The design takes advantage of an efficient transformation of testosterone leading to the synthesis of the key diene, 7α-(buta-1,3-dienyl)-4-androsten-17ß-ol-3-one, through an elimination reaction. It was found that in some instances the same reaction led to partial epimerization of the 17ß-hydroxyl group into the 17α-hydroxyl group. The specific orientation of the hydroxyl function was confirmed by NMR spectroscopy. Capitalizing on this unforeseen side reaction, several dimers were assembled using an olefin metathesis reaction with Hoveyda-Grubbs catalyst. This led to the formation of two isomeric testosterone dimers with 17α-OH or 17ß-OH (14α and 14ß) as well as an androstenedione dimer (14). The new dimers and their respective precursors were tested on androgen-dependent (LNCaP) and androgen independent (PC3 and DU145) prostate cancer cells. It was discovered that the most active dimer was made of the natural hormone testosterone (14ß) with an average IC50 of 13.3 µM. In LNCaP cells, 14ß was ∼5 times more active than the antiandrogen drug cyproterone acetate (IC50 of 12.0 µM vs. 59.6 µM, respectively). At low concentrations (0.25-0.5 µM), 14α and 14ß were able to completely inhibit LNCaP cell growth induced by testosterone or dihydrotestosterone. Furthermore, cross-reactivity of androgen-based dimers with sterol-metabolizing cytochrome P450 3A4 was explored and the results are disclosed herein.

Synthesis of some steroidal mitocans of nanomolar cytotoxicity acting by apoptosis.

Several steroids (abiraterone, prednisone, testosterone, cholesterol) and the BCL-2 inhibitor bexarotene were used as starting materials to synthesize iperazinyl-spacered rhodamine B conjugates. The conjugates were screened for their cytotoxicity in SRB assays against several human tumor cell lines and found to be active in a low µM to nM range. The conjugate derived from testosterone held an EC50 = 59 nM against MCF-7 tumor cells and acted mainly by necrosis. The prednisone conjugate, however, was less cytotoxic but acted mainly by apoptosis and held a moderate selectivity against MCF-7 tumor cells.

ENDOCRINE HISTORY: The history of discovery, synthesis and development of testosterone for clinical use.

As the most important male hormone, testosterone has an impact on almost all organs and body functions. The biological effects of testosterone and the testes have been known since antiquity, long before testosterone was identified as the active agent. Practical applications of this knowledge were castration of males to produce obedient servants, for punishment, for preservation of the prepubertal soprano voice and even for treatment of diseases. Testes were used in organotherapy and transplanted as treatment for symptoms of hypogonadism on a large scale, although these practices had only placebo effects. In reaction to such malpractice in the first half of the 20th century science and the young pharmaceutical industry initiated the search for the male hormone. After several detours together with their teams in 1935, Ernst Laqueur (Amsterdam) isolated and Adolf Butenandt (Gdansk) as well as Leopold Ruzicka (Zürich) synthesized testosterone. Since then testosterone has been available for clinical use. However, when given orally, testosterone is inactivated in the liver, so that parenteral forms of administration or modifications of the molecule had to be found. Over 85 years the testosterone preparations have been slowly improved so that now physiological serum levels can be achieved.

Testosterone- and vitamin-grafted cellulose ethers for sustained release of camptothecin.

Camptothecin (CPT), a potent anticancer drug with known antiviral activity, is halted of clinical use. Few drug delivery systems of CPT are approved for therapy. Hereby, we propose the encapsulation of hydrophobic CPT in the inner core of cellulose nanoaggregates for sustained release with retaining of antiproliferative activity. Cellulose conjugates were synthesized by esterification of methyl cellulose, hydroxyethyl cellulose and (hydroxypropyl)methyl cellulose with testosterone, ergocalciferol and dl-α-tocopherol hemisuccinates. The degree of substitution attained ranged from 0.004 to 0.025 and no depolymerization was observed by size exclusion chromatography. ATR-FTIR and NMR spectroscopies confirmed grafting of testosterone and vitamins to celluloses. According to dynamic light scattering, it resulted in their self-assembly in aqueous medium as stable and slightly negatively charged nanoaggregates of 213 to 731 nm. Nanoaggregates formation was also assessed using transmission electron and atomic force microscopies. CPT was encapsulated in the cellulose nanoaggregates, achieving a content of 1.7-13.0 wt %. Sustained release of camptothecin over 150 h was observed in simulated physiological conditions. CPT-loaded cellulose nanoparticles appeared to be possible candidates for chemotherapy, according to observed cytotoxicity against MCF-7 cancer cells.

Synthesis, pharmacological evaluation and docking studies of progesterone and testosterone derivatives as anticancer agents.

Steroidal hormones progesterone and testosterone play a vital role in breast and prostate cancers. In this research, we have synthesized and characterized a total of thirty-one (31) new nitrogenous derivatives of progesterone and testosterone. The synthesized derivatives (1-31) were screened for their anti-cancer potential against MCF-7 and PC-3 cell lines of breast using MTT assay. The compounds 1-31exhibited significant inhibitory potentials against MCF-7 and PC-3 cell lines. In MCF-7 assay, compound 17 displayed IC50 value of 04 ±â€¯0.02 µM while compound 18 was leading in PC-3 assay with IC50 of 03.14 ±â€¯0.4 µM. Tamoxifen was used as positive control which exhibited an IC50of 0.12 ±â€¯0.03 and 0.26 ±â€¯0.01 µM against MCF-7 and PC-3 respectively. The compounds also showed good anti-inflammatory activity according to oxidative burst inhibition by chemiluminescence technique where ibuprofen was used as positive control with 73.2 ±â€¯1.4% ROS inhibition. The compounds showed the percent ROS inhibition between 23.2 ±â€¯0.2 and -3.2 ±â€¯4.1. The results of the compounds were compared with the positive control ibuprofen. Molecular docking correlations suggest that the compounds exerted their inhibitory activity by binding to the active of the enzyme.

Synthesis and structural elucidation of a dehydrochloromethyltestosterone metabolite.

The human urinary long-term metabolite "M3" (4-chloro-17ß-hydroxymethyl-17α-methyl-18-norandrost-13-en-3-ol) of the common doping agent DHCMT has thus far been detected via GC/MS-MS, creating ambiguities concerning its absolute configuration. Its structure was elucidated via the synthesis of all eight possible stereoisomers with 17ß-hydroxymethyl configuration. The highlights of the synthesis consist of a novel first generation approach to 4ß-chloro-5ß compounds as well as a divergent route which allows easy access to the remaining A-ring chlorohydrins.

Synthesis and basic evaluation of 7α-(3-[18F]fluoropropyl)-testosterone and 7α-(3-[18F]fluoropropyl)-dihydrotestosterone.

OBJECTIVE: 7α-Substituted androgen derivatives may have the potential to visualize androgen receptors with positron emission tomography. In the present study, we synthesized fluoropropyl derivatives of 7α-(3-[18F]fluoropropyl)-testosterone ([18F]7) and 7α-(3-[18F]fluoropropyl)-dihydrotestosterone ([18F]15), and characterized their in vitro binding, in vivo biodistribution, and performed blocking studies in mature androgen deprived male rats. METHODS: We synthesized [18F]7 and [18F]15. In vitro binding to recombinant rat AR ligand binding domain protein was determined using a competitive radiometric ligand-binding assay with the high-affinity synthetic androgen [17α-methyl-3H]-methyltrienolone ([3H]R1881). In vivo biodistribution was performed in mature male rats treated with diethylstilbestrol (chemical castration). A blocking study was performed by co-administration of dihydrotestosterone (36 µg/animal). RESULTS: 7α-(3-Fluoropropyl)-testosterone (7) and 7α-(3-fluoropropyl)-dihydrotestosterone (15) showed competitive binding to recombinant rat AR ligand binding domain protein. The IC50 value of 15 (13.0 ± 3.3 nM) was higher than 7 (47.8 ± 10.0 nM). In contrast to the AR binding affinity, the ventral prostate uptake of [18F]7 and [18F]15 at 2 h post-injection was similar (0.07 % injected dose/g of tissue). A blocking study indicated that specific binding of [18F]15 is observed in the ventral prostate. [18F]7 and [18F]15 showed moderate levels of bone uptake, which indicates moderate metabolic de-fluorination in rodents. CONCLUSION: [18F]15 is better than [18F]7 in terms of radiochemical yield, in vitro binding affinity, prostate specific binding and stability against in vivo metabolic de-fluorination. However, the net uptake level of [18F]15 in prostate might be insufficient for in vivo visualization. Although [18F]7 and [18F]15 improved in vivo stability against de-fluorination, other basic characterization data in rodents were not superior to the current standard tracer 16ß-[18F]fluoro-5α-dihydrotestosterone. It is also revealed that the shorter side chain length of 7α-[18F]fluoromethyl-dihydrotestosterone is superior to the longer three carbon chain in [18F]15, in terms of net prostate uptake and in vivo metabolic stability.

Optimisation and validation of a new analytical method for the determination of four natural and synthetic hormones using LC-ESI-MS/MS.

A rapid liquid chromatographic-tandem mass spectrometric method was developed for the simultaneous determination of four natural and synthetic hormone residues (progesterone, testosterone, trenbolone acetate and zeranol) in animal tissue samples. Sample preparation was optimised to minimise time and solvent consumption. Meat samples were mechanically homogenised and digested in a procedure that gave similar recoveries to those enzymatically hydrolysed by Helix pomatia. Efficient extraction was achieved using acidified acetonitrile (1% acetic acid). Chromatographic conditions were optimised to minimise matrix effects. Analytes were separated using a C18 column with gradient elution using ammonium formate solution in methanol (MeOH)/water (1:9) and MeOH mobile phases. Finally, residues were qualitatively and quantitatively determined by electrospray ionisation tandem mass spectrometry in multiple reaction monitoring mode. Different parameters for LC-MS/MS (e.g., declustering potential and collision energy) were optimised using API 6500QT; all analytes were measured using positive-mode electrospray ionisation (ESI+) except zeranol which was measured in negative mode (ESI-). Due to LC-MS/MS signal enhancement/suppression, the determination of hormones was based on matrix-matched standard calculations. The method was validated for the four hormones on meat samples at different fortification levels and showed accepted performance criteria according to European Commission Decision 2002/657/EC. Decision limits and detection capabilities were estimated for all analytes.

Cu (I) catalyzed alkyne-azide 1,3-dipolar cycloaddition (CuAAC): Synthesis of 17α-[1-(substituted phenyl)-1,2,3-triazol-4-yl]-19-nor-testosterone-17ß-yl acetates targeting progestational and antipro-liferative activities.

The progestational potency and selectivity of synthetic steroidal agonists can be enhanced by even larger chemical moieties at 17α-position of the steroid backbones. Hereby a series 5a-c and 6a-c of novel 17α-[1-(substituted phenyl)-1,2,3-triazol-4-yl]-19-nortestosterone-17ß-yl acetates were designed and synthesized using click chemistry approach searching progestogenic derivatives with potential anticancer activity. Compounds 5a,b and 6a,c have affected to different extents the three histopatho-logical parameters considered for evaluation of their progestational activity. The compounds 5a,b and 6a,c showed modifications in rat uterus at 35.7-34.8 nM levels with privileged endometrial thickening effect and least change of uterine weight relative to NEA at 52.9 nM level. Up to 40 mg/kg dose compounds 5b and 6c were non-toxic. Molecular docking of the ligands in PR showed in the majority of cases a conformational fitting into the active site different from that of the reference steroid NEA. Compound 6b revealed about 46.4% growth inhibition of CNS cancer SNB-75 cell line, 56% growth inhibition of renal cancer A498 cell line and 56.7% growth inhibition of prostate cancer PC-3 cell line which was mediated by cell cycle arrest. Drugability of the screened compounds showed tolerated results after being challenged to diverse physicochemical parameters.

The impact of testosterone, tibolone and black cohosh on purified mammary and placental 17ß-hydroxysteroid dehydrogenase type 1.

CONTEXT: Mammary and placental 17ß-hydroxysteroid dehydrogenase type 1 (17ßHSD1). OBJECTIVE: To assess the impact of testosterone, tibolone, and black cohosh on purified mammary and placental 17ßHSD1. MATERIALS AND METHODS: 17ßHSD1 was purified from human mammary gland and placenta by column chromatography, its activity was monitored by a radioactive activity assay, and the degree of purification was determined by gel electrophoresis. Photometric cofactor transformation analysis was performed to assess 17ßHSD1 activity without or in presence of testosterone, tibolone and black cohosh. RESULTS: 17ßHSD1 from both sources displayed a comparable basal activity. Testosterone and tibolone metabolites inhibited purified mammary and placental 17ßHSD1 activity to a different extent, whereas black cohosh had no impact. DISCUSSION: Studies on purified enzymes reveal the individual action of drugs on local regulatory mechanisms thus helping to develop more targeted therapeutic intervention. CONCLUSION: Testosterone, tibolone and black cohosh display a beneficial effect on local mammary estrogen metabolism by not affecting or decreasing local estradiol exposure.

Mucor hiemalis mediated 14α-hydroxylation on steroids: in vivo and in vitro investigations of 14α-hydroxylase activity.

Transformation of testosterone and progesterone into synthetically challenging 14α-hydroxy derivatives was achieved by using fungal strain Mucor hiemalis. Prolonged incubation led to the formation of corresponding 6ß/7α,14α-dihydroxy metabolites. The position and stereochemistry of newly introduced hydroxyl group was determined by detailed spectroscopic analyses. The time course experiment indicated that fungal strain initiated transformation by hydroxylation at 14α-position followed by at 6ß- or 7α-positions. Studies using cell-free extracts suggest that the 14α-hydroxylase activity is NADPH dependent and belongs to the cytochrome P450 family.

Synthesis and bioconversions of formestane.

In an effort to generate new steroidal aromatase inhibitors, formestane (4-hydroxyandrost-4-ene-3,17-dione) (1) was biotransformed by Rhizopus oryzae to yield the known 4ß,5α-dihydroxyandrostane-3,17-dione as the major product (5) and bioconverted by Beauveria bassiana to afford the known reduced 4,17ß-dihydroxyandrost-4-en-3-one (6) and 3α,17ß-dihydroxy-5ß-androstan-4-one (7) and the new 4,11α,17ß-trihydroxyandrost-4-en-3-one (8). All the metabolites showed more potent activities than their parent congener in the aromatase and MCF-7 breast cancer assays. The bioactivities and structural elucidation of these metabolites as well as the semisynthesis of formestane (1) from testosterone (2) are reported herein.

First synthesis of separable isomeric testosterone dimers showing differential activities on prostate cancer cells.

The synthesis of two separable isomeric testosterone dimers is reported. The dimers are made from testosterone in a 5 step sequence and with 36% overall yield. The key dimerization step was performed using Hoveyda-Grubb's metathesis catalysts on 7alpha-allyltestosterone with 75% yield. The synthesis led to separable isomeric dimers (trans and cis, 2:1). X-ray diffraction crystallography, performed on monocrystal of the minor isomer, confirms the cis geometry of the double bound between the two testosterone units. MTT assays showed that the cis dimer has the highest activity against prostate cancer cell lines. The novel cis dimer is more active than the antiandrogen cyproterone acetate indicating the possible therapeutic value of this molecule.

Matrix effects on an antigen immobilized format for competitive enzyme immunoassay of salivary testosterone.

Matrix interferences in salivary testosterone enzyme immunoassays are important in the development of direct ELISA. An alternative format for sensitive enzyme immunoassay of testosterone was developed using immobilization of the antigen as part of a protein conjugate using oligoethylene glycol linker to project the antigen, with color development via enzyme labeled secondary antibody. This technique gave the required sensitivity for detection of testosterone from male saliva with a limit of detection (LOD) of 8.9 pg/mL (31 pmol/L). Application of the immunoassay directly in human saliva gave suppression of binding signals for the samples, indicating clear matrix interference with antibody binding. A wide variety of treatments were used in an attempt to overcome this effect, including use of both synthetic saliva and stripped human saliva for standard preparation, use of bovine serum albumin (BSA) to reduce non-specific binding of contaminants, pH adjustment of samples and/or standards and use of different antibodies. None of these techniques proved effective, causing either substantial suppression or enhancement of signal, and dilution was not possible because of the very low physiological concentrations. Complete removal of the saliva medium by chemical extraction was the only technique studied that could overcome this problem. These issues have not been explored previously for direct ELISA of salivary testosterone using alternative assay formats and have implications for the design of small molecule plate-based immunoassays in this medium.

Synthesis of 5,10-seco analogs of testosterone.

A number of 5,10-seco analogs of testosterone has been synthesized starting from products of the radical oxidation of 3beta,17beta-diacetoxy-5alpha-androstan-5alpha-ol. The obtained compounds possess a flexible 10-membered ring with substituents (O, -OH) at C-3 and C-5. Similar derivatives with an (E)- and (Z)-Delta(1(10))-double bond have been prepared also. X-ray analysis and a combination of NMR experiments have been used for their structure elucidation and conformation analysis.

Synthesis of 7alpha-(fluoromethyl)dihydrotestosterone and 7alpha-(fluoromethyl)nortestosterone, structurally paired androgens designed to probe the role of sex hormone binding globulin in imaging androgen receptors in prostate tumors by positron emission tomography.

Although prostate cancer growth is regulated by androgens through the androgen receptor (AR), in vitro assays of AR levels in prostate tumors have limited prognostic value. This might be improved by direct measurement of tumor AR in vivo using positron emission tomography (PET) imaging with fluorine-18-labeled androgens. Most AR PET imaging agents have been designed to limit steroid binding to serum proteins, but there is evidence that binding to sex hormone binding globulin (SHBG) might enhance tumor uptake. To probe the role of SHBG in prostate tumor uptake of PET imaging agents, we have synthesized two fluoro steroids, 7alpha-(fluoromethyl)dihydrotestosterone (7alpha-FM-DHT) and 7alpha-(fluoromethyl)nortestosterone (7alpha-FM-norT), by a route amenable to their labeling with [18F]fluoride ion. Both compounds have high affinity for AR, but 7alpha-FM-norT has much lower affinity for SHBG. Thus, these two fluoro steroids are well matched in terms of their site of fluorine labeling, similarity of structure, and equivalent AR binding affinity-but contrasting SHBG binding-and therefore can be used as agents for evaluating the role of SHBG binding in the target tissue uptake of AR PET imaging agents in humans.

Metabolism of 4-hydroxyandrostenedione and 4-hydroxytestosterone: Mass spectrometric identification of urinary metabolites.

4-Hydroxyandrost-4-ene-3,17-dione is a second generation, irreversible aromatase inhibitor and commonly used as anti breast cancer medication for postmenopausal women. 4-Hydroxytestosterone is advertised as anabolic steroid and does not have any therapeutic indication. Both substances are prohibited in sports by the World Anti-Doping Agency, and, due to a considerable increase of structurally related steroids with anabolic effects offered via the internet, the metabolism of two representative candidates was investigated. Excretion studies were conducted with oral applications of 100mg of 4-hydroxyandrostenedione or 200mg of 4-hydroxytestosterone to healthy male volunteers. Urine samples were analyzed for metabolic products using conventional gas chromatography-mass spectrometry approaches, and the identification of urinary metabolites was based on reference substances, which were synthesized and structurally characterized by nuclear magnetic resonance spectroscopy and high resolution/high accuracy mass spectrometry. Identified phase-I as well as phase-II metabolites were identical for both substances. Regarding phase-I metabolism 4-hydroxyandrostenedione (1) and its reduction products 3beta-hydroxy-5alpha-androstane-4,17-dione (2) and 3alpha-hydroxy-5beta-androstane-4,17-dione (3) were detected. Further reductive conversion led to all possible isomers of 3xi,4xi-dihydroxy-5xi-androstan-17-one (4, 6-11) except 3alpha,4alpha-dihydroxy-5beta-androstan-17-one (5). Out of the 17beta-hydroxylated analogs 4-hydroxytestosterone (18), 3beta,17beta-dihydroxy-5alpha-androstan-4-one (19), 3alpha,17beta-dihydroxy-5beta-androstan-4-one (20), 5alpha-androstane-3beta,4beta,17beta-triol (21), 5alpha-androstane-3alpha,4beta,17beta-triol (26) and 5alpha-androstane-3alpha,4alpha,17beta-triol (28) were identified in the post administration urine specimens. Furthermore 4-hydroxyandrosta-4,6-diene-3,17-dione (29) and 4-hydroxyandrosta-1,4-diene-3,17-dione (30) were determined as oxidation products. Conjugation was diverse and included glucuronidation and sulfatation.