50-28-2Relevant articles and documents
ANDROGEN METABOLISM IN MALE AND FEMALE BREAST TISSUE
Perel, E.,Davis, S.,Killinger, D. W.
, p. 345 - 352 (1981)
Incubation studies have been carried out using normal breast tissue and breast tissue from patients with gynecomastia, mammary dysplasia and breast carcinoma to determine the pattern of androstenedione metabolism.All tissues formed estrone (E1) and testosterone (T) in all incubations.Estradiol (E2) was isolated in incubations of tissue from 1 of 6 patients with mammary dysplasia, 5 of 6 patients with gynecomastia and in all incubations with normal and carcinoma tissue.Estrone formation was lowest in mammary dysplasia and gynecomastia, and higher in apparently normal breast tissue.The greatest E1 formation was found in incubations with breast carcinoma tissue, although there was considerable variation within this tissue group.Estradiol formation was low in all tissues, with the highest conversion rates in carcinoma tissue.Testosterone formation in carcinoma tissue was greater than in mammary dysplasia or gynecomastia, but similar to apparently normal tissue.These results indicate that breast tissue from different pathological states varies in its capacity to aromatize androstenedione (A) to estrogenic products and to convert it to other androgens.They have also shown that the pattern of metabolism is distinctive for the nature of the pathological abnormality.
Mechanism of action of bolandiol (19-nortestosterone-3β,17β-diol), a unique anabolic steroid with androgenic, estrogenic, and progestational activities
Attardi, Barbara J.,Page, Stephanie T.,Hild, Sheri A.,Coss, Christopher C.,Matsumoto, Alvin M.
, p. 151 - 161 (2010)
Bolandiol is a synthetic anabolic steroid that increases lean body mass and bone mineral density without significant stimulation of sex accessory glands in castrate adult male rats. Since bolandiol suppresses gonadotropins and endogenous testosterone (T) production, we investigated its mechanism of action. We compared the potency of bolandiol in vitro and in vivo with T, 5α-dihydrotestosterone (DHT), 19-nortestosterone (19-NT) and estradiol (E2). Bolandiol bound with lower affinity to the recombinant rat androgen receptor (AR) than the other androgens and had low, but measurable, affinity for recombinant human progestin receptors (PR-A, PR-B), and estrogen receptors (ERα and β-1). Functional agonist activity was assessed in transcription assays mediated by AR, PR, or ER. Bolandiol was stimulatory in all these assays, but only 4-9% as potent as T, DHT, and 19-NT via AR, 1% as potent as progesterone via PR, and 3% and 1% as potent as E2 acting through ERα or ERβ, respectively. In immature castrate rats, bolandiol was equipotent to T in stimulating growth of the levator ani muscle but less potent than T in stimulating growth of the sex accessory glands. Bolandiol also stimulated uterine weight increases in immature female rats, which were partly blocked by ICI 182,780, but it was not aromatized in vitro by recombinant human aromatase. In contrast to T, stimulation of sex accessory gland weights by bolandiol was not inhibited by concomitant treatment with the dual 5α-reductase inhibitor dutasteride. As bolandiol exhibits tissue selectivity in vivo, it may act via AR, PR, and/or ER, utilize alternative signaling pathway(s) or transcriptional coregulators, and/or be metabolized to a more potent selective steroid.
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Whitman,Wintersteiner,Schwenk
, p. 789,794 (1937)
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INHIBITION OF ESTROGEN SYNTHESIS IN HUMAN BREAST TUMORS BY TESTOLOLACTONE AND BROMOANDROSTENEDIONE
Budnick, Rose Marie,Dao, Thomas L.
, p. 533 - 542 (1980)
The inhibition of aromatase enzyme in human breast tumors by Δ1-testololactone, testololactone, 6α-bromoandrostenedione, and 6β-bromoandrostenedione was investigated.Estrone and estradiol synthesis from androstenedione was reduced in 3 tumor incubations by the presence of 0.13 mmol Δ1-testololactone and testololactone. 6α- and 6β-bromoandrostenedione (2.0 μM) were also shown to block estrogen synthesis in 2 tumors.Furthermore, Lineweaver-Burk plots revealed that all 4 compounds are competitive inhibitors of androstenedione aromatization.An apparent Km of the aromatase enzyme for androstenedione of 0.08 μM and a Vmax of 23 pmol of estrone synthesized/g tumor/hr were determined for one human breast tumor specimen.These results demonstrate that these aromatase inhibitors may be useful for the treatment of breast cancer.
Thermodynamic Meerwein-Ponndorf-Verley reduction in the diastereoselective synthesis of 17α-estradiol
Ahmed, Gulzar,Nickisch, Klaus
, p. 1 - 4 (2016)
The synthesis of 17α-hydroxy steroids generally requires multiple synthetic manipulations. The synthesis of 17α-estradiol is no exception, as this process involves the protection and release of the 3-hydroxy functional group. The diastereoselective reduction of the 17-keto-steroid can be utilized to prepare 17α-hydroxy-steroids. Here, 17α-estradiol was synthesized from commercially available estrone under thermodynamic Meerwein-Ponndorf-Verley (MPV) conditions in a single step, followed by simple chromatographic separation over silica gel. The remaining mixture of unreacted estrone and estradiols was easily recycled through Oppenauer oxidation to estrone, with an overall yield of 68% 17α-estradiol.
Estramustine binding in rat, baboon and human prostate measured by high pressure liquid chromatography
Kirdani,Corrales,Hoisaeter,Karr,Murphy,Sandberg
, p. 471 - 484 (1981)
High pressure liquid chromatography (HPLC) was used to determine 3H-estramustine (estradiol-17β3N-bis-[2-chlorethyl] carbamate), 3H-17β-hydroxy-5α-androstan-3-one (3H-dihydrotestosterone or 3H-DHT), 3H-estradiol-17β (3H-E2) and 3H-3β-hydroxy-5-pregnen-20-one (3H-pregnenolone) binding in 50μl of cytosol utilizing a column which separates proteins in the molecular weight range of 2,000 to 70,000 daltons. The rat prostate contains a protein in considerable concentration and with the highest affinity for estramustine (375,000dpm 3H-estramustine per mg. cytosol protein) among the substances tested. Operationally, we have named this protein 'estramustine binding protein' (EBP), though it is very likely similar to other previously described prostatic proteins (e.g., α-protein, prostatein, prostatic binding protein). The sensitivity of the HPLC method disclosed EBP-like proteins, but in much lesser concentrations, in some of the other tissues tested. The concentration of these proteins in the human and baboon prostates was much lower (average for the baboon cranial lobe 4800dpm/mg cytosol protein, with a somewhat higher value for the caudal lobe) than that in the rat gland. The amount of the EBP-like protein was higher in prostatic cancer than in that of benign prostatic hypertrophy (BPH) (range 9350 - 25,900 vs. 2200 - 18,900 dpm/mg cytosol protein). In the human, the highest value was found in one normal prostate tested (106,000 dpm/mg) cytosol protein).
An environmentally friendly and cost effective synthesis of estradiol featuring two novel reagents: Si(0)/KF and PMHS/hexamethyldisiloxane/pTSA
Lim, Chongsoo,Evenson, Gerald N.,Perrault, William R.,Pearlman, Bruce A.
, p. 6417 - 6420 (2006)
Si(0)/KF is introduced as a strong, inexpensive, environmentally friendly, and safe reagent for 'dissolving metal'-type reduction. PMHS/hexamethyldisiloxane/pTSA is introduced as an inexpensive substitute for Et3SiH/TFA for 'ionic hydrogenation', where the hexamethyldisiloxane functions as a capping agent to block the oligomeric silicone by-product from cross-linking to a gel, rubber, or plastic. An environmentally friendly and cost effective synthesis of estradiol is described which showcases these new reagents.
Catalytic properties of pristine and defect-engineered Zr-MOF-808 metal organic frameworks
Mautschke,Drache,Senkovska,Kaskel,Llabrés Xamena
, p. 3610 - 3616 (2018)
Various defect-engineered Zr-trimesate MOF-808 compounds (DE-MOF-808) have been prepared by mixing the tricarboxylate ligands with dicarboxylate ligands; viz. isophthalate, pyridine-3,5-dicarboxylate, 5-hydroxy-isophthalate, or 5-amino-isophthalate. The resulting mixed-ligand compounds, MOF-808-X (X = IP, Pydc, OH or NH2) were all found to be highly crystalline and isostructural to the unmodified MOF-808. Pristine MOF-808 showed better catalytic performance than a UiO-66 reference compound for the Meerwein-Ponndorf-Verley (MPV) reduction of carbonyl compounds. This was attributed to a higher availability of coordinatively unsaturated Zr4+ sites (cus) in MOF-808 upon removal of formate ions. Meanwhile, cus in UiO-66 are only located at defect sites and are thus much less abundant. Further improvement of the catalytic activity of defect-engineered MOF-808-IP and MOF-808-Pydc was observed, which may be related with the occurrence of less crowded Zr4+ sites in DE-MOF-808. The wider pore structure of MOF-808 with respect to UiO-66 compounds translates into a sharp improvement of the activity for the MPV reduction of bulky substrates, as shown for estrone reduction to estradiol. Interestingly, MOF-808 produces a notable diastereoselectivity towards the elusive 17-α-hydroxy estradiol.
Potent aromatase inhibitors through fungal transformation of anti-cancer drug testolactone: An approach towards treatment of breast cancer
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Paragraph 0021, (2021/07/30)
Biotransformation of an aromatase inhibitor, testolactone (1), yielded five new metabolites, 7α-hydroxy-3-oxo-13,17-secoandrosta-1,4-dieno-17,13α-lactone (2), 7β-hydroxy-3-oxo-13,17-seco-5β-androsta-1-eno-17,13α-lactone (3), 3α,11β-dihydroxy-13,17-seco-5β-androsta-17,13α-lactone (4), 4β,5β-epoxy-3β-hydroxy-13,17-secoandrosta-1-eno-17,13α-lactone (5), and 4β,5β-epoxy-3α-hydroxy-13,17-secoandrosta-1-eno-17,13α-lactone (6). Aromatase (estrogen synthase) involves in the synthesis of estrogen, and promotes the growth of breast cancerous cells. It is a key target for the discovery of chemotherapeutic agents against ER+ (estrogen-positive) breast-cancers and several other diseases caused by overexpression of aromatase enzyme. Metabolites 3 (IC50=8.60±0.402 nM), and 4 (IC50=9.23±1.31 nM) were identified as potent inhibitors against human aromatase enzyme, in comparison to 1 (IC50=0.716±0.031 μM), and the standard aromatase inhibiting drug, exemestane (IC50=0.232±0.031 μM). Derivatives 2 (IC50=11.68±0.73 μM), 5 (IC50=10.37±0.50 μM) and 6 (IC50=0.82±0.059 μM) have also a good inhibition against aromatase enzyme. Therefore, metabolites 2-6 have the potential to serve as therapeutic agents against diseases caused by aromatase enzyme, including breast cancer.
One-Step Chemo-, Regio- and Stereoselective Reduction of Ketosteroids to Hydroxysteroids over Zr-Containing MOF-808 Metal-Organic Frameworks
Llabrés i Xamena, F. X.,Mautschke, H.-H.
, p. 10766 - 10775 (2021/06/15)
Zr-containing MOF-808 is a very promising heterogeneous catalyst for the selective reduction of ketosteroids to the corresponding hydroxysteroids through a Meerwein-Ponndorf-Verley (MPV) reaction. Interestingly, the process leads to the diastereoselective synthesis of elusive 17α-hydroxy derivatives in one step, whereas most chemical and biological transformations produce the 17β-OH compounds, or they require several additional steps to convert 17β-OH into 17α-OH by inverting the configuration of the 17 center. Moreover, MOF-808 is found to be stable and reusable; it is also chemoselective (only keto groups are reduced, even in the presence of other reducible groups such as C=C bonds) and regioselective (in 3,17-diketosteroids only the keto group in position 17 is reduced, while the 3-keto group remains almost intact). The kinetic rate constant and thermodynamic parameters of estrone reduction to estradiol have been obtained by a detailed temperature-dependent kinetic analysis. The results evidence a major contribution of the entropic term, thus suggesting that the diastereoselectivity of the process is controlled by the confinement of the reaction inside the MOF cavities, where the Zr4+ active sites are located.
Chiral Imidazo[1,5- a]pyridine-Oxazolines: A Versatile Family of NHC Ligands for the Highly Enantioselective Hydrosilylation of Ketones
Chinna Ayya Swamy,Varenikov, Andrii,Ruiter, Graham De
supporting information, p. 247 - 257 (2020/02/04)
Herein we report the synthesis and application of a versatile class of N-heterocyclic carbene ligands based on an imidazo[1,5-a]pyridine-3-ylidine backbone that is fused to a chiral oxazoline auxiliary. The key step in the synthesis of these ligands involves the installation of the oxazoline functionality via a microwave-assisted condensation of a cyano-azolium salt with a wide variety of 2-amino alcohols. The resulting chiral bidentate NHC-oxazoline ligands form stable complexes with rhodium(I) that are efficient catalysts for the enantioselective hydrosilylation of structurally diverse ketones. The corresponding secondary alcohols are isolated in good yields (typically >90%) with good to excellent enantioselectivities (80-93% ee). The reported hydrosilylation occurs at ambient temperatures (40 °C), with excellent functional group tolerability. Even ketones bearing heterocyclic substituents (e.g., pyridine or thiophene) or complex organic architectures are hydrosilylated efficiently, which is discussed further in this report.