Synthesis and evaluation for uterotrophic and antiimplantation activities of 2-substituted estradiol derivatives

Synthesis and biological evaluation of some novel 4H-benzopyran-4-one derivatives as nonsteroidal antiestrogens

The preparation and characterization of some novel 2- and 3-substituted-7-methoxy-4H-1-benzopyran-4-one are presented. The synthesized compounds were evaluated for their uterotrophic, antiuterotrophic and antiimplantation activities in mature female albino rats. 3-Benzyl-7-methoxy-4H-1-benzopyran-4-one (14) showed the highest uterotrophic activity (87%) based on dry uterine weight gain. The antifertility activity, as assessed by the post-coital antiimplantation activity test, was of weak potency for most compounds (14-29%). Among the products, the 2-(4'-methoxyphenyl)-7-methoxy-4H-1-benzopyran-4-one (19) exhibited the highest antiestrogenic activity of 65%. It also elicited 31% of the uterotrophic activity of estradiol.

Synthesis, uterotrophic, and antiuterotrophic activities of some estradiol derivatives containing thiadiazole, thiazoline, and thiazolidinone moieties

The effect of structural modification on the biological activity of hormones has been studied on five novel series of estradiol analogs bearing a variety of substituents at the 2-position of the steroidal nucleus. The synthesized compounds include 2-[2-(5-substituted amino-1,3,4-thiadiazol-2-yl)vinyl]estradiol 17 beta-acetate 5-9, 2-aroylmethylestradiols 10-12, 2-[2-aryl-2-(substituted thiocarbamoylhydrazono)ethyl]estradiols 13-18 and their cyclic thiazoline 19-24, and thiazolidinone derivatives 25-30. Among the products, the p-hydroxybenzolmethylestradiol 12 exhibited the highest antiestrogenic activity of 63%. It also elicited 34% of the uterotrophic activity of estradiol.

Novel steroidal 1,4-diketones and pyridazine derivatives as potential antiestrogens

A series of steroidal 1,4-diketone derivatives was synthesized by acid-catalyzed condensation of 2-acetylestradiol-17 beta-acetate with substituted phenylglyoxals. Conversion of the products into the corresponding pyridazine derivatives was achieved by reaction with hydrazine hydrate. The synthesized compounds were evaluated for their uterotrophic, antiuterotrophic, and antifertility activities in mature female albino rats. Among the compounds tested, the phenyl 2, p-bromophenyl 3, and p-methoxyphenyl 5 diketone derivatives displayed uterotrophic activity of 72%, 72%, and 91%, respectively. The gradation of antiestrogenic activity was assessed in vivo by the inhibition of the estrone-stimulated uterine growth. Compounds 2-5 showed moderate antiestrogenic activity of 53-56%. None of the tested compounds elicited antifertility activity as assessed by the post-coital antiimplantation activity test.

4',17-dioxo-5'H-estra-1(10),4-dieno[3,2-b]furan: synthesis, binding affinity to the estrogen receptor, uterotrophic and antiimplantation activities

4',17-Dioxo-5'H-estra-1(10),4-dieno[3,2-b]furan (3) has been prepared by several routes starting from 2-bromoacetylestrone (2). Performance of the reaction with thiourea at elevated temperature provided compound 3 in good yield. When other reagents such as thiosemicarbazide, morpholine, sodium hydroxide or sodium hydride were treated with 2-bromoacetylestrone at room temperature, the furano derivative 3 was also obtained as the sole product. This new type of structural modification provided an estrogen nucleus deprived of the 3-hydroxyl function which was previously thought to be an essential requisite for binding to the estrogen receptor (ER). When evaluated in vitro for binding to the ER and in vivo for uterotrophic and antifertility activities, the furano derivative 3 was capable of inhibiting [3H]E2 binding by 16% while still eliciting high uterotrophic (99%) and postcoital antiimplantation (100%) activities relative to estradiol.