Estramustine phosphate sodium

    WARNING: This product is for research use only, not for human or veterinary use.

MedKoo CAT#: 100310

CAS#: 52205-73-9 (Estramustine phosphate sodium), 2998-57-4 (Estramustine phosphoric acid)

Description: Estramustine phosphate sodium is a synthetic molecule that combines estradiol and nornitrogen mustard through a carbamate link. Estramustine and its major metabolite estramustine bind to microtubule-associated proteins (MAPs) and tubulin, thereby inhibiting microtubule dynamics and leading to anaphase arrest in a dose-dependent fashion. This agent also exhibits anti-androgenic effects. Check for active clinical trials or closed clinical trials using this agent. (NCI Thesaurus).

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Estramustine phosphate sodium, purity > 98%, is in stock. Current shipping out time is about 2 weeks after order is received. CoA, QC data and MSDS documents are available in one week after order is received.

Chemical Structure


Theoretical Analysis

MedKoo Cat#: 100310
Name: Estramustine phosphate sodium
CAS#: 52205-73-9 (Estramustine phosphate sodium), 2998-57-4 (Estramustine phosphoric acid)
Chemical Formula: C23H32Cl2NNa2O7P
Exact Mass:
Molecular Weight: 582.36
Elemental Analysis: C, 47.44; H, 5.54; Cl, 12.18; N, 2.41; Na, 7.90; O, 19.23; P, 5.32

Synonym: estramustine Phosphate; US brand name: Emcyt. Foreign brand name: Estracyt. Abbreviation: EM. Code names: Leo299; Ro 222296000.

IUPAC/Chemical Name: (8R,9S,13S,14S,17S)-13-methyl-17-(phosphonooxy)-7,8,9,11,12,13,14,15,16,17-decahydro-6H-cyclopenta[a]phenanthren-3-yl bis(2-chloroethyl)carbamate hydrate


InChi Code: InChI=1S/C23H32Cl2NO6P.H2O/c1-23-9-8-18-17-5-3-16(31-22(27)26(12-10-24)13-11-25)14-15(17)2-4-19(18)20(23)6-7-21(23)32-33(28,29)30;/h3,5,14,18-21H,2,4,6-13H2,1H3,(H2,28,29,30);1H2/t18-,19-,20+,21+,23+;/m1./s1

SMILES Code: O=C(OC1=CC=C2[C@@]3([H])CC[C@]4(C)[C@@H](OP(O)(O)=O)CC[C@@]4([H])[C@]3([H])CCC2=C1)N(CCCl)CCCl.[H]O[H]

Technical Data

Solid powder

>98% (or refer to the Certificate of Analysis)

Shipping Condition:
Shipped under ambient temperature as non-hazardous chemical. This product is stable enough for a few weeks during ordinary shipping and time spent in Customs.

Storage Condition:
Dry, dark and at 0 - 4 C for short term (days to weeks) or -20 C for long term (months to years).

Soluble in DMSO, not in water

Shelf Life:
>2 years if stored properly

Drug Formulation:
This drug may be formulated in DMSO

Stock Solution Storage:
0 - 4 C for short term (days to weeks), or -20 C for long term (months).

Harmonized System Code:

Additional Information

Estramustine phosphate sodium, an antineoplastic agent, is an off-white powder readily soluble in water. EMCYT Capsules are white and opaque, each containing estramustine phosphate sodium as the disodium salt monohydrate equivalent to 140 mg estramustine phosphate, for oral administration. Each capsule also contains magnesium stearate, silicon dioxide, sodium lauryl sulfate, and talc. Gelatin capsule shells contain the following pigment: titanium dioxide. Chemically, estramustine phosphate sodium is estra-1,3,5(10)-triene-3,17-diol(17β)-,3­ [bis(2-chloroethyl)carbamate] 17-(dihydrogen phosphate), disodium salt, monohydrate. It is also referred to as estradiol 3-[bis(2-chloroethyl)carbamate] 17-(dihydrogen phosphate), disodium salt, monohydrate. Estramustine phosphate sodium has an empiric formula of C23H30Cl2NNa2O6P•H2O, a calculated molecular weight of 582.4.
Estramustine phosphate (Figure 1) is a molecule combining estradiol and nornitrogen mustard by a carbamate link. The molecule is phosphorylated to make it water soluble.
Estramustine phosphate taken orally is readily dephosphorylated during absorption, and the major metabolites in plasma are estramustine (Figure 2), the estrone analog (Figure 3), estradiol, and estrone.
Prolonged treatment with estramustine phosphate produces elevated total plasma concentrations of estradiol that fall within ranges similar to the elevated estradiol levels found in prostatic cancer patients given conventional estradiol therapy. Estrogenic effects, as demonstrated by changes in circulating levels of steroids and pituitary hormones, are similar in patients treated with either estramustine phosphate or conventional estradiol. The metabolic urinary patterns of the estradiol moiety of estramustine phosphate and estradiol itself are very similar, although the metabolites derived from estramustine phosphate are excreted at a slower rate.


1: Matsumoto K, Tanaka N, Hayakawa N, Ezaki T, Suzuki K, Maeda T, Ninomiya A, Nakamura S. Efficacy of estramustine phosphate sodium hydrate (EMP) monotherapy in castration-resistant prostate cancer patients: report of 102 cases and review of literature. Med Oncol. 2013 Dec;30(4):717. doi: 10.1007/s12032-013-0717-2. Epub 2013 Sep 5. PubMed PMID: 24005812.

2: Koie T, Ohyama C, Yamamoto H, Hatakeyama S, Yoneyama T, Hashimoto Y, Kamimura N. Safety and effectiveness of neoadjuvant luteinizing hormone-releasing hormone agonist plus low-dose estramustine phosphate in high-risk prostate cancer: a prospective single-arm study. Prostate Cancer Prostatic Dis. 2012 Dec;15(4):397-401. doi: 10.1038/pcan.2012.29. Epub 2012 Aug 14. PubMed PMID: 22890389.

3: Minato A, Fujimoto N, Kubo T, Harada S, Akasaka S, Matsumoto T. Efficacy of estramustine phosphate according to risk classification of castration-resistant prostate cancer. Med Oncol. 2012 Dec;29(4):2895-900. doi: 10.1007/s12032-012-0178-z. Epub 2012 Feb 10. PubMed PMID: 22323054.

4: Narita S, Tsuchiya N, Kumazawa T, Maita S, Numakura K, Obara T, Tsuruta H, Saito M, Inoue T, Horikawa Y, Satoh S, Nanjyo H, Habuchi T. Short-term clinicopathological outcome of neoadjuvant chemohormonal therapy comprising complete androgen blockade, followed by treatment with docetaxel and estramustine phosphate before radical prostatectomy in Japanese patients with high-risk localized prostate cancer. World J Surg Oncol. 2012 Jan 4;10:1. doi: 10.1186/1477-7819-10-1. PubMed PMID: 22214417; PubMed Central PMCID: PMC3267659.

5: Ravery V, Fizazi K, Oudard S, Drouet L, Eymard JC, Culine S, Gravis G, Hennequin C, Zerbib M. The use of estramustine phosphate in the modern management of advanced prostate cancer. BJU Int. 2011 Dec;108(11):1782-6. doi: 10.1111/j.1464-410X.2011.10201.x. Epub 2011 Jul 14. Review. PubMed PMID: 21756277.

6: Narita S, Tsuchiya N, Yuasa T, Maita S, Obara T, Numakura K, Tsuruta H, Saito M, Inoue T, Horikawa Y, Satoh S, Habuchi T. Outcome, clinical prognostic factors and genetic predictors of adverse reactions of intermittent combination chemotherapy with docetaxel, estramustine phosphate and carboplatin for castration-resistant prostate cancer. Int J Clin Oncol. 2012 Jun;17(3):204-11. doi: 10.1007/s10147-011-0275-6. Epub 2011 Jun 25. PubMed PMID: 21706123.

7: Hirayama Y, Ito Y, Kanamaru T, Sonoda T, Aoyama M, Nakamura N, Kawamura M. [A case of castration-refractory prostate cancer showing marked decrease of serum PSA level after zoledronic acid treatment with estramustine phosphate and prednisolone]. Gan To Kagaku Ryoho. 2011 Mar;38(3):485-7. Japanese. PubMed PMID: 21403461.

8: Scott LM, Chen L, Daniel KG, Brooks WH, Guida WC, Lawrence HR, Sebti SM, Lawrence NJ, Wu J. Shp2 protein tyrosine phosphatase inhibitor activity of estramustine phosphate and its triterpenoid analogs. Bioorg Med Chem Lett. 2011 Jan 15;21(2):730-3. doi: 10.1016/j.bmcl.2010.11.117. Epub 2010 Dec 4. PubMed PMID: 21193311; PubMed Central PMCID: PMC3034307.

9: Higashioka M, Yamaguchi E, Takatori S, Tanaka M, Kyoi T. [Effect of the 5-HT3 receptor antagonist granisetron on estramustine phosphate sodium (Estracyt)-induced emesis in ferrets]. Hinyokika Kiyo. 2010 Jul;56(7):361-5. Japanese. PubMed PMID: 20724808.

10: Nakagami Y, Ohori M, Sakamoto N, Koga S, Hamada R, Hatano T, Tachibana M. Safety and efficacy of docetaxel, estramustine phosphate and hydrocortisone in hormone-refractory prostate cancer patients. Int J Urol. 2010 Jul;17(7):629-34. doi: 10.1111/j.1442-2042.2010.02544.x. Epub 2010 Apr 26. PubMed PMID: 20438593.