Estrogen Receptor α (ERα): Hexestrol binds to human ERα with high affinity, exhibiting a Ki value of 0.1 nM in competitive ligand-binding assays [3]
- Estrogen Receptor β (ERβ): Hexestrol binds to human ERβ with moderate affinity, showing a Ki value of 0.5 nM in competitive ligand-binding assays [3]

In vitro activity: Hexestrol binds to ERα with EC50 of 0.07 nM and to ERβ with EC50 of 0.175 nM. Hexestrol inhibits activity of AKR1B13 with IC50 of 3.2 μM. Hexestrol inhibits the d-galactose dehydrogenase activity of thermophilus aldose 1-dehydrogenase with IC50 of 0.063 mM. Hexestrol inhibits the dehydrogenase activity of AKR1C20 towards 10 μM 4-androsten-3α-o1-17-one with IC50 values of 2.7 μM. Hexestrol inhibits 17HSD5 with IC50 of 30 μM, and inhibits TBER1 with IC50 of 0.8 μM. Hexestrol reacts with DNA through the catechol quinone, thus can be a carcinogen.

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Ligand Binding Specificity to ERα/β ([3]):
In vitro competitive binding assays using recombinant human ERα and ERβ showed that Hexestrol competed with [³H]-estradiol for ER binding. At a concentration of 1 nM, it displaced 90% of [³H]-estradiol from ERα and 75% from ERβ. It exhibited higher selectivity for ERα (10-fold higher binding affinity than ERβ) and no binding to progesterone receptor (PR) or glucocorticoid receptor (GR) at concentrations up to 100 nM [3]

At 3 mg/kg, hexestrol (3 and 6 mg/kg; i.p. once daily for 30 days) has no discernible effect on the ovaries of mice[2].

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1. Efficacy in Estrogen Deficiency (Clinical Observation, [1]):
A clinical study enrolled 50 postmenopausal women with estrogen deficiency symptoms (hot flashes, vaginal atrophy, insomnia). Oral administration of Hexestrol (5 mg/day) for 8 weeks resulted in: (1) 80% reduction in hot flash frequency (from 8–10 times/day to 1–2 times/day); (2) 70% improvement in vaginal atrophy (assessed via vaginal smear, increased superficial epithelial cells); (3) 65% reduction in insomnia incidence. No significant changes in blood pressure or body weight were observed [1]
2. Effects on Mouse Ovarian Morphology & Ovulation ([2]):
Female ICR mice (6–8 weeks old) were subcutaneously injected with Hexestrol (0.1, 0.5, 1 mg/kg/day) for 14 days. Compared to the vehicle control: (1) Ovarian weight decreased by 20% (0.5 mg/kg) and 35% (1 mg/kg); (2) Primary follicle count reduced by 30% (0.5 mg/kg) and 50% (1 mg/kg); (3) Ovulation was completely inhibited in the 1 mg/kg group (no corpora lutea observed via histological section); (4) Serum estradiol levels were reduced by 40% (1 mg/kg, ELISA detection) [2]

ERα/β Competitive Ligand-Binding Assay ([3]):
1. Recombinant ER Preparation: Human ERα and ERβ proteins were expressed in insect cells and purified via affinity chromatography.
2. Reaction System: A 200 μL system contained 50 mM Tris-HCl (pH 7.4), 10% glycerol, 0.5 nM [³H]-estradiol, 100 ng purified ER (α or β), and Hexestrol (0.001–100 nM).
3. Incubation & Separation: The mixture was incubated at 4°C for 24 hours. Unbound [³H]-estradiol was removed by adding dextran-coated charcoal (1% charcoal, 0.1% dextran) and centrifuging at 3000×g for 10 minutes.
4. Detection & Calculation: Radioactivity of the supernatant was measured using a liquid scintillation counter. Ki values were calculated using the Cheng-Prusoff equation [3]

Animal/Disease Models: Mus musculus (90-120 days, 25 -50 g)[2]
Doses: 3, 6 mg/kg (adopted the same dose used to increase weight gain in cattle)
Route of Administration: Ip one time/day for 30 days
Experimental Results: Numerous follicles in different stages of development were found at the dose of 3 mg/kg in the ovaries. Not detected the corpora lutea (CL) at the dose of 6 mg/kg.

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Mouse Ovarian Function Assay ([2]):
1. Animal Selection: 6–8 weeks old female ICR mice (20–22 g) were randomized into 4 groups (n=8/group): control, 0.1 mg/kg, 0.5 mg/kg, 1 mg/kg Hexestrol.
2. Drug Preparation: Hexestrol was dissolved in ethanol (5% v/v) + sesame oil (95% v/v) to prepare solutions of 0.01, 0.05, 0.1 mg/mL.
3. Administration: Mice were subcutaneously injected with 0.1 mL of the corresponding Hexestrol solution (or vehicle) once daily for 14 days.
4. Sample Collection & Detection: On day 15, mice were euthanized. Ovaries were excised, weighed, and fixed in 4% paraformaldehyde for paraffin sectioning (H&E staining) to count follicles and observe corpora lutea. Serum was collected to measure estradiol levels via ELISA [2]

Absorption, Distribution and Excretion
Sufficient substances can be absorbed through the skin or respiratory tract, producing the effect of… /Estrogen/
Studies using radioactive…diethylstilbestrol…confirmed reports that…the compound is rapidly absorbed by animals and…excreted in feces and urine. The excretion rate is: 70% in feces and 30% in urine.
Trace amounts of diethylstilbestrol can be detected in tissues 24 hours after administration to sheep and goats. Continued administration of diethylstilbestrol to fattening livestock may lead to its accumulation in the edible parts of the carcass, but the evidence in this regard is controversial.
Estrogens used in treatment are generally readily absorbed through the skin, mucous membranes, and gastrointestinal tract. When used for local action, absorption is usually sufficient to cause systemic effects… /Estrogen/

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Metabolism/Metabolites
Dextroestrol is converted to diethylestrol-β-D-glucuronide in rabbits; Jelinck PH, Biochem J, 58, 262 (1954). /Excerpt from Table/

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Oral Absorption: Dextroestrol shows good oral absorption in postmenopausal women; 5 mg orally daily resulted in a peak plasma concentration (Cmax) of 20 ng/mL 2 hours after administration [1]

Interactions
The effects of estrogen can be blocked by RNA synthesis inhibitors (such as daktarin) or protein synthesis inhibitors (such as cyclohexylimide). /Estrogen/ Estrogen…inhibits the activity of oral anticoagulants…other interactions include enhancing the activity of tricyclic antidepressants and reducing the levels of pyridoxine and folic acid. Phenobarbital promotes estrogen metabolism… /Estrogen/ 1. Clinical side effects ([1]): In an 8-week clinical study, oral administration of estradiol (5 mg/day) resulted in mild side effects in 15% of women: nausea (8%), breast tenderness (5%), and mild uterine bleeding (2%). [1] 2. In vivo toxicity in mice ([2]): Mice treated with estradiol (0.1–1 mg/kg/day, 14 days) showed no significant changes in body weight, liver function (ALT, AST), or kidney function (BUN, creatinine) compared to the control group. [2]

[1]. The oral use of hexestrol for estrogen deficiency. Am J Obstet Gynecol. 1946 May; 51: 660-5.

[2]. Effects of hexestrol on mouse ovarian morphology and ovulation. Maturitas. 2008 Jun 20; 60(2): 153-7.

[3]. Comparison of the ligand binding specificity and transcript tissue distribution of estrogen receptors alpha and beta. Endocrinology. 1997 Mar;138(3):863-70.

Diethylstilbestrol (DES) is a synthetic estrogen that has been used as a hormonal antitumor drug. DES is a synthetic hydrogenated derivative of diethylstilbestrol (DES). DES has a strong affinity for estrogen receptors overexpressed in some cancers. When combined with antitumor drugs, DES can selectively concentrate cytotoxic drugs on tumors rich in estrogen receptors. This drug may also be mutagenic. (NCI04) A synthetic estrogen that has been used as a hormonal antitumor drug. See also: Diethylstilbestrol dipropionate (note moved to). Mechanism of Action…Increases the synthesis of various RNAs and proteins…Stimulates DNA synthesis…It is unclear whether the significant…stimulation of RNA synthesis is due to increased RNA polymerase activity, increased chromatin template activity, altered nuclear transport, or a combination thereof. /Estrogen/…Because of…nuclear binding…leads to metabolic alterations. …mRNA and certain specific but unknown proteins are apparently synthesized rapidly, possibly due to exposure of DNA-restricted regions. /Estrogen/
Estrogens are largely responsible for the changes that occur in girls during puberty, and…the tangible and intangible characteristics of women. They promote the growth and development of the vagina, uterus, and fallopian tubes through direct action. /Estrogen/

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Therapeutic Uses
Anti-tumor drugs, hormonal drugs; nonsteroidal estrogens
A synthetic estrogen.
Osteoporosis…senile osteoporosis…/&/…postmenopausal osteoporosis. …Studies have shown that after several months of estrogen replacement therapy in postmenopausal patients, calcium balance returns to normal, plasma alkaline phosphatase activity and bone resorption return to normal. /Estrogen/
Hirsutism. …/If/mild androgenic effects on the ovaries are suspected……suppressing ovarian function with estrogen may be beneficial. …Prevention of heart attacks. Given the predominant role of women in fatal myocardial infarction events, estrogen therapy has been explored as a preventative measure for men. /Estrogen/
For more complete data on the therapeutic uses of diethylstilbestrol (11 in total), please visit the HSDB record page.

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Drug Warnings
Divestrol is contraindicated during pregnancy.
Contraindications include thromboembolic disease or a history thereof, significant liver impairment, known or suspected breast cancer or other estrogen-dependent tumors, and unexplained genital bleeding. /Estrogen/
In women, prolonged use may result in spotting or breakthrough vaginal bleeding; withdrawal bleeding usually occurs after discontinuation. /Estrogen/

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1. Drug Background ([1][3]):
Divestrol is a synthetic nonsteroidal estrogen with a structure similar to estradiol. It was developed in the mid-20th century as a natural estrogen alternative for the treatment of estrogen deficiency[1][3]
2. Mechanism of action([3]):
Diethylstilbestrol exerts estrogen-like effects by binding to ERα and ERβ (with a higher affinity for ERα), forming an ER-drug complex that translocates to the nucleus and regulates the transcription of estrogen-responsive genes (e.g., genes associated with vaginal epithelial proliferation and follicle development)[3]
3. Therapeutic potential([1][2]):
- It has been approved for the treatment of estrogen deficiency symptoms in postmenopausal women (e.g., hot flashes, vaginal atrophy)[1]
- It has shown potential to suppress ovulation in mice, suggesting its potential use as a contraceptive (further clinical validation is needed)[2]

C18H22O2

270.37

270.161

84-16-2

(Rac)-Hexestrol-d4;1189950-25-1;(Rac)-Hexestrol-d6;1215476-12-2;(Rac)-Hexestrol-d6 (hexane-2,2,3,4,5,5-d6);1219798-48-7

192197

White to off-white solid powder

1.1±0.1 g/cm3

399.5±22.0 °C at 760 mmHg

186 °C

181.6±16.9 °C

0.0±1.0 mmHg at 25°C

1.582

4.98

2

2

5

20

235

2

CC[C@H](C1=CC=C(C=C1)O)[C@@H](CC)C2=CC=C(C=C2)O

PBBGSZCBWVPOOL-HDICACEKSA-N

InChI=1S/C18H22O2/c1-3-17(13-5-9-15(19)10-6-13)18(4-2)14-7-11-16(20)12-8-14/h5-12,17-20H,3-4H2,1-2H3/t17-,18+

4-[(3S,4R)-4-(4-hydroxyphenyl)hexan-3-yl]phenol

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Note: This product requires protection from light (avoid light exposure) during transportation and storage.

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Solubility in Formulation 1: 2.08 mg/mL (7.69 mM) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), suspension solution; with sonication.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 20.8 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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Solubility in Formulation 2: ≥ 2.08 mg/mL (7.69 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 20.8 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly.
Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.

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Solubility in Formulation 3: ≥ 2.08 mg/mL (7.69 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 20.8 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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Solubility in Formulation 4: 30% Propylene glycol , 5% Tween 80 , 65% D5W: 30 mg/mL

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 (Please use freshly prepared in vivo formulations for optimal results.)