ru-16117 ru-16117 ru-16117 is an estrogen medication which was investigated for the potential treatment of symptoms of estrogen deficiency such as hot flashes and osteoporosis in women but was never marketed. it was developed for use by mouth. ru-16117clinical dataother names11α-methoxyethinylestradiol; 11α-methoxy-17α-ethynylestradiol; 11α-methoxy-19-nor-17α-pregna-1,3,5(10)-trien-20-yne-3,17-diolroutes ofadministrationby mouthdrug classestrogen; estrogen etheridentifiers iupac name (8s,9s,11r,13s,14s,17r)-17-ethynyl-11-methoxy-13-methyl-7,8,9,11,12,14,15,16-octahydro-6h-cyclopentaphenanthrene-3,17-diol cas number61665-15-4pubchem cid66408chemspider59782comptox dashboard (epa)dtxsid60977244 chemical and physical dataformulac21h26o3molar mass326.436 g·mol−13d model (jsmol)interactive image smiles c12c(3(1cc2(c#c)o)ccc4=c3c=cc(=c4)o)oc inchi inchi=1s/c21h26o3/c1-4-21(23)10-9-17-16-7-5-13-11-14(22)6-8-15(13)19(16)18(24-3)12-20(17,21)2/h1,6,8,11,16-19,22-23h,5,7,9-10,12h2,2-3h3/t16-,17-,18+,19+,20-,21-/m0/s1key:mtmzziptqitgcy-qhocjjnxsa-n pharmacology pharmacodynamics ru-16117 is an estrogen, or an agonist of the estrogen receptor (er). in mouse uterine tissue, it shows about 5 to 13% of the affinity of estradiol for the er and about 1% of the estrogenic activity of estradiol. conversely, it shows no affinity for the androgen, progesterone, glucocorticoid, and mineralocorticoid receptors, nor any activities associated with interactions with these receptors. while the association rate of ru-16117 to the er is the same as that of moxestrol, it dissociates from the er extremely rapidly at rates of about three times faster than estradiol and about 20 times faster than moxestrol. this is similar to the case of estriol, which ru-16117 is described as sharing similarities with. ru-16117 is described as a weak or partial estrogen or a mixed estrogen/antiestrogen. it has been described as having highly active antiestrogenic activity with very weak uterotrophic activity. however, higher doses and/or prolonged administration of ru-16117 have been reported to induce equivalent estrogenic responses relative to estradiol and moxestrol. relative affinities (%) of ru-16117 and related steroids compoundprarergrmrshbgcbg estradiol2.67.91000.60.138.7<0.1 estriol ? ?15 ? ? ? ? ethinylestradiol15–251–31121–3<1 ? ? moxestrol (11β-meo-ee)0.8<0.1123.2<0.1<0.2<0.1 ru-16117 (11α-meo-ee)1–3<113<1<1 ? ? values are percentages (%). reference ligands (100%) were progesterone for the pr, testosterone for the ar, e2 for the er, dexa for the gr, aldosterone for the mr, dht for shbg, and cortisol for cbg. chemistry