Clomestrone

Chemical compound

Clomestrone
Clinical data

Trade names	Arterolo, Atheran, Colesterel, Iposclerone, Liprotene, Persclerol
Other names	SC-8246; 16α-Chloroestrone 3-methyl ether; 16α-Chloro-3-methoxyestra-1,3,5(10)-trien-17-one
Routes of administration	By mouth
Drug class	Estrogen; Estrogen ether
Identifiers
IUPAC name (8R,9S,13S,14S,16R)-16-chloro-3-methoxy-13-methyl-7,8,9,11,12,14,15,16-octahydro-6H-cyclopenta[a]phenanthren-17-one
CAS Number	4091-75-2
PubChem CID	107501
ChemSpider	96732
UNII	P1L5F7667L
CompTox Dashboard (EPA)	DTXSID50878418
ECHA InfoCard	100.021.669
Chemical and physical data
Formula	C₁₉H₂₃ClO₂
Molar mass	318.84 g·mol⁻¹
3D model (JSmol)	Interactive image
SMILES CC12CCC3C(C1CC(C2=O)Cl)CCC4=C3C=CC(=C4)OC
InChI InChI=1S/C19H23ClO2/c1-19-8-7-14-13-6-4-12(22-2)9-11(13)3-5-15(14)16(19)10-17(20)18(19)21/h4,6,9,14-17H,3,5,7-8,10H2,1-2H3/t14-,15-,16+,17-,19+/m1/s1 Key:UQIPVSBPFZSWGD-ILYVXUQDSA-N

Clomestrone (brand names Arterolo, Atheran, Colesterel, Iposclerone, Liprotene, Persclerol, others; former developmental code name SC-8246), also known as 16α-chloroestrone 3-methyl ether, is a synthetic, steroidal, weak estrogen derived from estrone and used as an anticholesterolemic agent in the treatment of atherosclerosis.^[1]^[2] It is said to have beneficial effects on serum lipid profiles while producing minimal feminization, though some estrogenic side effects, including breast tenderness, loss of libido, and fatigue or avolition, were observed in most patients in clinical studies.^[3]^[4] The drug is a close analogue of mytatrienediol, and the two estrogens have similar drug profiles.^[5] Clomestrone was described in the literature in 1958 and introduced for medical use shortly thereafter.^[1]

References

^ ^a ^b J. Elks (14 November 2014). The Dictionary of Drugs: Chemical Data: Chemical Data, Structures and Bibliographies. Springer. pp. 297–298. ISBN 978-1-4757-2085-3.
^ Gregory Pincus (22 October 2013). Hormones and Atherosclerosis: Proceedings of the Conference Held in Brighton, Utah, March 11-14, 1958. Elsevier Science. pp. 253–374. ISBN 978-1-4832-7064-7.
^ RIVIN AU (1959). "SC 8246, a new estrogen analog: lipoprotein effects with minimal feminization". Metab. Clin. Exp. 8: 704–8. PMID 14437693. SC-8246 (16-alpha chlorestrone 3-methyl ether) was administered for periods of six to twelve months to 20 male survivors of acute myocardial infarction ranging in age from 30 to 63 years. A significant decrease in serum cholesterol concentration occurred in only 6 of 13 patients with an initial cholesterol level above 250 mg. per 100 ml., and there was no change in the other 7. Of 7 initial cholesterol levels below 250 mg. per 100 ml., no level decreased, 3 increased, and 4 were unchanged. In 9 of 11 patients with an initial alpha:beta lipoprotein ratio of less than 20 per cent, a significant increase occurred, but no change in the other 2. Among 9 subjects with a ratio initially above 20 per cent, a further increase occurred in 8 while taking the drug. This estrogen appeared to have an advantage in terms of lessening side-effects. Mild breast tenderness or gynecomastia occurred in 15 of the 17 patients with a "favorable" lipoprotein change. When the dosage was reduced to 5 mg. daily or every other day, the lipoprotein effect in 8 of them could be sustained while the breast changes disappeared. Libido disappeared from 2 patients and was diminished in 1 other. Other side-effects were nausea in 1 patient, loss of ambition in 5, and itching or dryness of the skin in 4.
^ WINSOR T, FISHER EK, PAYNE JH (1959). "A method for the study of peripheral arteriosclerosis". J Am Geriatr Soc. 7 (2): 167–74. doi:10.1111/j.1532-5415.1959.tb01062.x. PMID 13630690. S2CID 46048052.
^ Cancer Chemotherapy Abstracts. Information Resources Press. January 1960. p. 143.

Estrogens and antiestrogens

Estrogens

ERTooltip Estrogen receptor agonists	Steroidal: Alfatradiol Certain androgens/anabolic steroids (e.g., testosterone, testosterone esters, methyltestosterone, metandienone, nandrolone esters) (via estrogenic metabolites) Certain progestins (e.g., norethisterone, noretynodrel, etynodiol diacetate, tibolone) Clomestrone Cloxestradiol acetate Conjugated estriol Conjugated estrogens Epiestriol Epimestrol Esterified estrogens Estetrol^† Estradiol Estradiol esters (e.g., estradiol acetate, estradiol benzoate, estradiol cypionate, estradiol enanthate, estradiol undecylate, estradiol valerate, polyestradiol phosphate, estradiol ester mixtures (Climacteron)) Estramustine phosphate Estriol Estriol esters (e.g., estriol succinate, polyestriol phosphate) Estrogenic substances Estrone Estrone esters Estrone sulfate Estropipate (piperazine estrone sulfate) Ethinylestradiol^# Ethinylestradiol sulfonate Hydroxyestrone diacetate Mestranol Methylestradiol Moxestrol Nilestriol Prasterone (dehydroepiandrosterone; DHEA) Prasterone enanthate Prasterone sulfate Promestriene Quinestradol Quinestrol Nonsteroidal: Benzestrol Bifluranol Chlorotrianisene Dienestrol Dienestrol diacetate Diethylstilbestrol (stilbestrol) Diethylstilbestrol esters/ethers Dimestrol (diethylstilbestrol dimethyl ether) Fosfestrol (diethylstilbestrol diphosphate) Mestilbol (diethylstilbestrol monomethyl ether) Doisynoestrol (fenocycline) Hexestrol Hexestrol esters Methallenestril Methestrol (promethestrol) Methestrol dipropionate (promethestrol dipropionate) Paroxypropione Quadrosilan Triphenylbromoethylene Triphenylchloroethylene Zeranol
Progonadotropins	Antiandrogens (e.g., bicalutamide) GnRH agonists (e.g., GnRH (gonadorelin), leuprorelin) Gonadotropins (e.g., FSHTooltip follicle-stimulating hormone, LHTooltip luteinizing hormone)

ERTooltip Estrogen receptor agonists

Steroidal: Alfatradiol
Certain androgens/anabolic steroids (e.g., testosterone, testosterone esters, methyltestosterone, metandienone, nandrolone esters) (via estrogenic metabolites)
Certain progestins (e.g., norethisterone, noretynodrel, etynodiol diacetate, tibolone)
Clomestrone
Cloxestradiol acetate
Conjugated estriol
Conjugated estrogens
Epiestriol
Epimestrol
Esterified estrogens
Estetrol^†
Estradiol
Estradiol esters (e.g., estradiol acetate, estradiol benzoate, estradiol cypionate, estradiol enanthate, estradiol undecylate, estradiol valerate, polyestradiol phosphate, estradiol ester mixtures (Climacteron))
Estramustine phosphate
Estriol
Estriol esters (e.g., estriol succinate, polyestriol phosphate)
Estrogenic substances
Estrone
Estrone esters
- Estrone sulfate
- Estropipate (piperazine estrone sulfate)
Ethinylestradiol^#
- Ethinylestradiol sulfonate
Hydroxyestrone diacetate
Mestranol
Methylestradiol
Moxestrol
Nilestriol
Prasterone (dehydroepiandrosterone; DHEA)
- Prasterone enanthate
- Prasterone sulfate
Promestriene
Quinestradol
Quinestrol

Progonadotropins

Antiandrogens (e.g., bicalutamide)
GnRH agonists (e.g., GnRH (gonadorelin), leuprorelin)
Gonadotropins (e.g., FSHTooltip follicle-stimulating hormone, LHTooltip luteinizing hormone)

Antiestrogens

ERTooltip Estrogen receptor antagonists (incl. SERMsTooltip selective estrogen receptor modulators/SERDsTooltip selective estrogen receptor downregulators)	Acolbifene^† Anordrin Bazedoxifene Broparestrol Clomifene^# Cyclofenil Enclomifene^† Epitiostanol Lasofoxifene Mepitiostane Ormeloxifene Ospemifene Raloxifene Tamoxifen^# Toremifene Exclusively antagonistic: Elacestrant Fulvestrant Noncompetitive inhibitors: Trilostane
Aromatase inhibitors	First-generation: Aminoglutethimide Testolactone Second-generation: Fadrozole Formestane Third-generation: Anastrozole Exemestane Letrozole
Antigonadotropins	Androgens/anabolic steroids (e.g., testosterone, testosterone esters, nandrolone esters, oxandrolone, fluoxymesterone) D₂ receptor antagonists (prolactin releasers) (e.g., domperidone, metoclopramide, risperidone, haloperidol, chlorpromazine, sulpiride) GnRH agonists (e.g., leuprorelin, goserelin) GnRH antagonists (e.g., cetrorelix, elagolix) Progestogens (e.g., chlormadinone acetate, cyproterone acetate, gestonorone caproate, hydroxyprogesterone caproate, medroxyprogesterone acetate, megestrol acetate)
Others	Mixed mechanism of action: Danazol Gestrinone Androstenedione immunogens: Androvax (androstenedione albumin) Ovandrotone albumin (Fecundin)

^#WHO-EM
^‡Withdrawn from market
Clinical trials:
- ^†Phase III
- ^§Never to phase III

See also: Estrogen receptor modulators; Androgens and antiandrogens; Progestogens and antiprogestogens; List of estrogens

Estrogen receptor modulators

ERTooltip Estrogen receptor

Agonists	Steroidal: 2-Hydroxyestradiol 2-Hydroxyestrone 3-Methyl-19-methyleneandrosta-3,5-dien-17β-ol 3α-Androstanediol 3α,5α-Dihydrolevonorgestrel 3β,5α-Dihydrolevonorgestrel 3α-Hydroxytibolone 3β-Hydroxytibolone 3β-Androstanediol 4-Androstenediol 4-Androstenedione 4-Fluoroestradiol 4-Hydroxyestradiol 4-Hydroxyestrone 4-Methoxyestradiol 4-Methoxyestrone 5-Androstenediol 7-Oxo-DHEA 7α-Hydroxy-DHEA 7α-Methylestradiol 7β-Hydroxyepiandrosterone 8,9-Dehydroestradiol 8,9-Dehydroestrone 8β-VE2 10β,17β-Dihydroxyestra-1,4-dien-3-one (DHED) 11β-Chloromethylestradiol 11β-Methoxyestradiol 15α-Hydroxyestradiol 16-Ketoestradiol 16-Ketoestrone 16α-Fluoroestradiol 16α-Hydroxy-DHEA 16α-Hydroxyestrone 16α-Iodoestradiol 16α-LE2 16β-Hydroxyestrone 16β,17α-Epiestriol (16β-hydroxy-17α-estradiol) 17α-Estradiol (alfatradiol) 17α-Dihydroequilenin 17α-Dihydroequilin 17α-Epiestriol (16α-hydroxy-17α-estradiol) 17α-Ethynyl-3α-androstanediol 17α-Ethynyl-3β-androstanediol 17β-Dihydroequilenin 17β-Dihydroequilin 17β-Methyl-17α-dihydroequilenin Abiraterone Abiraterone acetate Alestramustine Almestrone Anabolic steroids (e.g., testosterone and esters, methyltestosterone, metandienone (methandrostenolone), nandrolone and esters, many others; via estrogenic metabolites) Atrimustine Bolandiol Bolandiol dipropionate Butolame Clomestrone Cloxestradiol Cloxestradiol acetate Conjugated estriol Conjugated estrogens Cyclodiol Cyclotriol DHEA DHEA-S ent-Estradiol Epiestriol (16β-epiestriol, 16β-hydroxy-17β-estradiol) Epimestrol Equilenin Equilin ERA-63 (ORG-37663) Esterified estrogens Estetrol Estradiol Estradiol esters Lipoidal estradiol Polyestradiol phosphate Estramustine Estramustine phosphate Estrapronicate Estrazinol Estriol Estriol esters Polyestriol phosphate Estrofurate Estrogenic substances Estromustine Estrone Estrone esters Estrone methyl ether Estropipate Etamestrol (eptamestrol) Ethinylandrostenediol Ethandrostate Ethinylestradiol Ethinylestradiol 3-benzoate Ethinylestradiol sulfonate Ethinylestriol Ethylestradiol Etynodiol Etynodiol diacetate Hexolame Hippulin Hydroxyestrone diacetate Lynestrenol Lynestrenol phenylpropionate Mestranol Methylestradiol Moxestrol Mytatrienediol Nilestriol Norethisterone Noretynodrel Orestrate Pentolame Prodiame Prolame Promestriene RU-16117 Quinestradol Quinestrol Tibolone Nonsteroidal: (R,R)-THC (S,S)-THC 2,8-DHHHC β-LGND1 β-LGND2 (GTx-878) AC-186 Allenestrol Allenolic acid Benzestrol Bifluranol Bisdehydrodoisynolic acid Butestrol Carbestrol D-15414 DCW234 Diarylpropionitrile Dienestrol Dienestrol diacetate Diethylstilbestrol Diethylstilbestrol esters Dimestrol (dianisylhexene) Dimethylstilbestrol Doisynoestrol (fenocycline) Doisynolic acid Efavirenz Elacestrant ERB-196 (WAY-202196) Erteberel (SERBA-1, LY-500307) Estrobin (DBE) Fenestrel FERb 033 Fosfestrol (diethylstilbestrol diphosphate) Furostilbestrol (diethylstilbestrol difuroate) GTx-758 Hexestrol Hexestrol esters ICI-85966 (Stilbostat) M2613 meso-Butestrol meso-Hexestrol Mestilbol Methallenestril Methestrol Methestrol dipropionate Paroxypropione Pentafluranol Phenestrol Prinaberel (ERB-041, WAY-202041) Propylpyrazoletriol Quadrosilan SC-3296 SC-4289 SERBA-2 SKF-82,958 Terfluranol Triphenylbromoethylene Triphenylchloroethylene Triphenyliodoethylene Triphenylmethylethylene (triphenylpropene) WAY-166818 WAY-169916 WAY-200070 WAY-204688 (SIM-688) WAY-214156 Unknown/unsorted: ERB-26 ERA-45 ERB-79 ZK-283197 Xenoestrogens: Anise-related (e.g., anethole, anol, dianethole, dianol, photoanethole) Chalconoids (e.g., isoliquiritigenin, phloretin, phlorizin (phloridzin), wedelolactone) Coumestans (e.g., coumestrol, psoralidin) Flavonoids (incl. 7,8-DHF, 8-prenylnaringenin, apigenin, baicalein, baicalin, biochanin A, calycosin, catechin, daidzein, daidzin, ECG, EGCG, epicatechin, equol, formononetin, glabrene, glabridin, genistein, genistin, glycitein, kaempferol, liquiritigenin, mirificin, myricetin, naringenin, penduletin, pinocembrin, prunetin, puerarin, quercetin, tectoridin, tectorigenin) Lavender oil Lignans (e.g., enterodiol, enterolactone, nyasol (cis-hinokiresinol)) Metalloestrogens (e.g., cadmium) Pesticides (e.g., alternariol, dieldrin, endosulfan, fenarimol, HPTE, methiocarb, methoxychlor, triclocarban, triclosan) Phytosteroids (e.g., digitoxin (digitalis), diosgenin, guggulsterone) Phytosterols (e.g., β-sitosterol, campesterol, stigmasterol) Resorcylic acid lactones (e.g., zearalanone, α-zearalenol, β-zearalenol, zearalenone, zeranol (α-zearalanol), taleranol (teranol, β-zearalanol)) Steroid-like (e.g., deoxymiroestrol, miroestrol) Stilbenoids (e.g., resveratrol, rhaponticin) Synthetic xenoestrogens (e.g., alkylphenols, bisphenols (e.g., BPA, BPF, BPS), DDT, parabens, PBBs, PHBA, phthalates, PCBs) Others (e.g., agnuside, rotundifuran)
Mixed (SERMsTooltip Selective estrogen receptor modulators)	2-Phenylbenzofuran 2-Phenylbenzothiophene 4'-Hydroxynorendoxifen 27-Hydroxycholesterol Acefluranol Acolbifene Afimoxifene Anordiol Anordrin Arzoxifene Bazedoxifene Brilanestrant Broparestrol Camizestrant Chlorotrianisene Clomifene Clomifenoxide CN-55945-27 Cyclofenil D-15413 Desmethylchlorotrianisene Droloxifene Enclomifene Endoxifen Etacstil (GW-5638, DPC-974) Ethamoxytriphetol (MER-25) Femarelle Fispemifene GW-7604 ICI-55548 Idoxifene Lasofoxifene Levormeloxifene LN-1643 LN-2299 LY-117018 Menerba Miproxifene Miproxifene phosphate MRL-37 Nafoxidine Nitromifene NNC 45-0095 NNC 45-0320 NNC 45-0781 NNC 45-1506 Ormeloxifene Ospemifene Panomifene Pipendoxifene Promensil Raloxifene Rimostil (P-081) Spironolactone SS1010 Tamoxifen TAS-108 (SR-16234) Toremifene Trioxifene TZE-5323 U-11555A U-11634 Y-134 Zindoxifene Zuclomifene
Antagonists	(R,R)-THC 7β-Hydroxy-DHEA Chloroindazole Cytestrol acetate EM-800 (SCH-57050) Epitiostanol ERA-90 ERB-88 Fulvestrant (ICI-182780) Glyceollins (I, II, III, IV) ICI-164384 MDL-101906 Mepitiostane Methylepitiostanol Methylpiperidinopyrazole MIBE Oxabicycloheptene sulfonate Phenytoin PHTPP Prochloraz RU-39411 RU-58668 SS1020 TAS-108 (SR-16234) ZB716 ZK-164015 ZK-191703 Coregulator-binding modulators: ERX-11 Noncompetitive inhibitors: Trilostane

GPERTooltip G protein-coupled estrogen receptor

Agonists	2-Methoxyestradiol 7β-Hydroxyepiandrosterone Afimoxifene (4-hydroxytamoxifen) Aldosterone Atrazine Bisphenol A Daidzein DDT (p,p'-DDT, o',p'-DDE) Diarylpropionitrile Equol Estradiol Ethinylestradiol Fulvestrant (ICI-182780) G-1 Genistein GPER-L1 GPER-L2 Hydroxytyrosol Kepone Niacin Niacinamide Nonylphenol Oleuropein PCBs (2,2',5'-PCB-4-OH) Propylpyrazoletriol Quercetin Raloxifene Resveratrol STX Tamoxifen Tectoridin
Antagonists	CCL18 Estriol G-15 G-36 MIBE
Unknown	Diethylstilbestrol Zearalenone

See also: Receptor/signaling modulators; Estrogens and antiestrogens; Androgen receptor modulators; Progesterone receptor modulators; List of estrogens