New 11 beta-aryl-substituted steroids exhibit both progestational and antiprogestational activity

First synthesis and characterization for the stereoisomers of Ulipristal acetate

The three stereoisomers, 11α,17α-isomer I, 11α,17β-isomer II and 11β,17β-isomer III are related substances of the selective progesterone receptor modulator Ulipristal acetate. Herein, we presented an efficient and practical synthesis approach to deliver these three stereoisomers for the first time, and also confirmed the structure of the key intermediate 5a by single-crystal X-ray analysis. Our research will be of immense help for organic chemists to study the impurity profile of Ulipristal acetate.

Synthesis and biological evaluation of 11' imidazolyl antiprogestins and mesoprogestins

Antiprogestins with a 4' para imidazolylphenyl moiety were synthesized and their biochemical interactions with the progesterone and glucocorticoid receptor were investigated. Depending on the substitution pattern at the 17 position partial progesterone receptor (PR)-agonistic derivatives like compounds EC339 and EC336 or pure antagonists like compound EC317 were obtained. EC317 was investigated in vivo and found to be significantly more potent than RU 486 in cycling and pregnant guinea pigs. For testing the biological action progesterone receptor modulators (PRM), guinea pigs appears as a specific model when compare to pregnant human uterus. This model correlates to human conditions such as softening and widening of the cervix, the elevation of the uterine responsiveness to prostaglandins and oxytocin, and finally to induction of labor. The use of non-pregnant guinea pigs permitted the simultaneous assessment of PR-agonistic and PR-antagonistic properties and their physiological interactions with uterine and vaginal environment. These can histologically be presumed from the presence of estrogen or progesterone dominance in the genital tract tissues. The ovarian histology indicated the effects on ovulation. Corpora lutea in guinea pigs further reflects inhibitory effects of the progesterone-dependent uterine prostaglandin secretion. PRMs are initially synthesized as analogues of RU 486. They represent a heterogeneous group of compounds with different ratios of PR-agonistic and-antagonistic properties. PR-agonistic properties may be essential for uterine anti-proliferative effects. In various clinical studies these were also attributed to RU 486 or Ulipristal [1,2]. Adjusted PR-agonistic PRMs (EC312, EC313) [3] may be more effective in achieving a mitotically resting endometrium and superior uterine tumor inhibition. For the use in termination of pregnancy, progesterone-inhibitory effects are essentially needed. Even minor PR-agonistic properties compromise the therapeutic goals. Pure PR-antagonists, as EC317, clearly exceeded the gold standard RU 486 with respect to labor inducing effects. Mechanistically it is surprising that both types of compound may be potent inhibitors of ovulation.

A new and efficient method for the synthesis of Ulipristal acetate

In this study, we describe another new and efficient route for preparing Ulipristal acetate. The 1,4-addition compound 5 was greatly improved after the starting material ketone 1 was underwent epoxidation, cyanation, hydroxyl group protection and Grignard addition. The synthetic procedure is only 6 steps and the total yield is about 27.4%, which is much suitable for industrial process.

A simple and convenient synthetic route to Ulipristal acetate

We set out to describe a new and efficient route for preparing Ulipristal acetate with a good yield. The selected epoxidization conditions gave out 80% of 5α,10α-epoxide 2a in the two diastereoisomers which greatly improved the yield of 11β-substituted isomer 4a. And phenyl-sulfinyl compound 6 was synthesized from ketone 5 directly treated with phenylsulfenyl chloride in the presence of triethylamine. These synthetic procedures is only 8 steps, less than currently reported in the literature, but more suitable for industrial process.

Synthesis and antiprogestational properties of novel 17-fluorinated steroids

Progesterone receptor (PR) plays a key role in reproductive functions, and compounds that inhibit progesterone action (antiprogestins) have potential use in the treatment of estrogen- and progesterone-dependent diseases, including uterine leiomyomas and breast cancer. In the present study, we chemically synthesized novel 17-fluorinated steroids and evaluated the cytotoxicity profiles of these compounds in T47D breast cancer cells compared to the activity of known antiprogestins, including ZK230 211, RU-486, CDB2914, CDB4124 and ORG33628. We analyzed in vitro receptor-binding assays and PR-transactivation assays to establish the antiprogestational activity of these molecules. The representative antiprogestin EC304 was found to inhibit in vitro tumorigenicity in a dose-dependent fashion in T47D cells by a colony formation assay at 1 and 10nM concentrations. The potent in vivo antiprogestational activity of EC304 was also demonstrated in an antinidation assay for the interruption of early pregnancy in rats. The strong antiprogestational activity and absence of antiglucocorticoid activity in EC compounds may demonstrate their utility in the treatment of leiomyoma, endometriosis and breast cancer.

Synthesis and biological evaluation of partially fluorinated antiprogestins and mesoprogestins

A series of antiprogestins have been synthesized by partially fluorinating the steroid molecule in positions relevant for receptor binding. By introducing fluorine at the exo-methylene of the 17 spirofuran ring, we obtained partial agonists (mesoprogestins) with significant applications for antiproliferative and antiovulatory treatment strategies in gynecological therapy such as uterine fibroids, endometriosis and heavy menstrual bleeding. Compared to the standard drug RU486, our synthesized compounds exhibited considerable dissociation between antiprogestational and antiglucocorticoid PR receptors. Furthermore, our studies have shown that pure antiprogestins can be generated by partially fluorinating the 17 propenyl and propynl group or by substituting the 4' acetyl phenyl group in the 11 position using trifluromethyl group.

Synthesis and identification of novel 11beta-aryl-4',5'-dihydrospiro[estra-4,9-diene-17beta,4'-oxazole] analogs with dissociated antiprogesterone activities

A series of novel 11beta-aryl-4',5'-dihydrospiro[estra-4,9-diene-17beta,4'-oxazole] analogs have been evaluated for their antagonist hormonal properties using the T47D cell-based alkaline phosphatase assay and the A549 cell-based functional assay. Some of the compounds showed highly potent, and more selective antiprogestational activity against antiglucocorticoid activity than mifepristone (RU 486).

Novel phosphorus-containing 17beta-side chain mifepristone analogues as progesterone receptor antagonists

A novel series of steroidal compounds were designed and synthesized with various phosphorus-containing groups on the 17beta-side chain as progesterone receptor antagonists. The structure-activity relationships of these compounds are discussed. Selected compounds were tested in an rat progesterone-sensitive assay. Some of these compounds are more potent than mifepristone, with a better selectivity profile in differentiating progesterone receptor from glucocorticoid receptor.

New progesterone receptor antagonists: phosphorus-containing 11beta-aryl-substituted steroids

A new series of phosphorus-containing 11beta-aryl-substituted steroids have been synthesized in an eight-step sequence involving a palladium-catalyzed coupling reaction to introduce a phosphorus group onto the aromatic ring. The compounds were evaluated for progesterone receptor (PR) antagonist activity in a T47D cell-based assay and for glucocorticoid receptor (GR) antagonist activity in an A549 cell-based assay. The structure-activity relationships of these compounds are discussed. Selected compounds were tested in vivo in a rat complement C3 assay.

Selective progesterone receptor modulator development and use in the treatment of leiomyomata and endometriosis

Selective progesterone receptor modulators (SPRMs) represent a new class of progesterone receptor ligands. SPRMs exert clinically relevant tissue-selective progesterone agonist, antagonist, or mixed agonist/antagonist effects on various progesterone target tissues in vivo. Asoprisnil (J867) is the first SPRM to reach an advanced stage of clinical development for the treatment of symptomatic uterine fibroids and endometriosis. Asoprisnil belongs to the class of 11beta-benzaldoxime-substituted estratrienes that exhibit partial progesterone agonist/antagonist effects with high progesterone receptor specificity in animals and humans. Asoprisnil has no antiglucocorticoid activity in humans at therapeutic doses. It exhibits endometrial antiproliferative effects on the endometrium and breast in primates. Unlike progesterone antagonists, asoprisnil does not induce labor in relevant models of pregnancy and parturition. It induces amenorrhea primarily by targeting the endometrium. In human subjects with uterine fibroids, asoprisnil suppressed both the duration and intensity of uterine bleeding in a dose-dependent manner and reduced tumor volume in the absence of estrogen deprivation. In subjects with endometriosis, asoprisnil was effective in reducing nonmenstrual pain and dysmenorrhea. Asoprisnil may, therefore, provide a novel, tissue-selective approach to control endometriosis-related pain. SPRMs have the potential to become a novel treatment of uterine fibroids and endometriosis.

Flavonoids can block PSA production by breast and prostate cancer cell lines

BACKGROUND

Prostatic carcinoma is the most commonly diagnosed cancer and the second leading cause of cancer death of North American men. Combined androgen blockade (CAB) is one treatment option for prostate cancer, using estrogen agonists, luteinizing hormone-releasing hormone (LHRH) agonists and non-steroidal anti-androgens such as nilutamide and cyproterone acetate. Since many of these drugs have serious side effects, many patients are searching for "natural" alternatives or complements to traditional therapy. These include phytoestrogens found in soy and other plant foods. Such compounds have only started to be evaluated for potential androgen-blocking activity. Inhibition of production of androgen-regulated proteins, including prostate-specific antigen (PSA), is one indicator of androgen blocking.

METHODS

The ability of 72 flavonoids and related compounds to inhibit PSA production in a breast cancer cell line, BT-474, and a prostate cancer cell line (PC-3), transfected with the human androgen receptor cDNA, PC-3(AR)(2) was examined.

RESULTS

Twenty-two of the 72 flavonoids tested were found to significantly block PSA production by the BT-474 cell line at the highest tested concentration (10(-5) mol/l), with 17 of these compounds inhibiting production of PSA in the PC-3(AR)(2) cells as well.

CONCLUSIONS

That several flavonoids may significantly block production of this androgen-regulated protein. It will be worthwhile to examine these compounds as possible candidates for prostate cancer prevention or management.