TAS-108 citrate

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MedKoo CAT#: 202840

CAS#: 229634-98-4

Description: TAS-108, also known as SR16234, is a synthetic, antiestrogenic steroidal compound with potential antitumor activity. TAS-108 binds to and inhibits estrogenic receptor alpha (ERa), mainly expressed in the mammary gland and uterus and upregulated in estrogen-dependent tumors. Blockage of ERa by TAS-108 prevents the binding and effects of estrogen and may lead to an inhibition of estrogen-dependent cancer cell proliferation. TAS-108 also is a partial agonist of the estrogenic receptor beta (ERb), expressed in many tissues including the central nervous system, urogenital tract, bone and cardiovascular system, thereby exerting a positive effect on these tissues.

Price and Availability

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Pricing updated 2020-06-02. Prices are subject to change without notice.

TAS-108 is not in stock, but may be available through custom synthesis. For cost-effective reason, minimum 1 gram order is requested. The product will be characterized by NMR, HPLC and MS analysis. Purity (HPLC) is usually >98%. CoA, QC data, MSDS will be provided when product is successfully made. The estimated lead time is 2-3 months. Please send email to sales@medkoo.com to inquire quote.

Chemical Structure


Theoretical Analysis

MedKoo Cat#: 202840
Name: TAS-108 citrate
CAS#: 229634-98-4
Chemical Formula: C39H55NO10
Exact Mass:
Molecular Weight: 697.85
Elemental Analysis: C, 78.37; H, 9.37; N, 2.77; O, 9.49

Related CAS #: 229634-98-4 (citrate)   229634-97-3 (free base)  

Synonym: TAS108, TAS-108, TAS108, SR16234, SR 16234, SR-16234

IUPAC/Chemical Name: (7R,8S,9S,13R,14S,17R)-17-(2-(4-((diethylamino)methyl)-2-methoxyphenoxy)ethyl)-7,13-dimethyl-7,8,9,11,12,13,14,15,16,17-decahydro-6H-cyclopenta[a]phenanthren-3-ol 2-hydroxypropane-1,2,3-tricarboxylate


InChi Code: InChI=1S/C33H47NO3.C6H8O7/c1-6-34(7-2)21-23-8-13-30(31(19-23)36-5)37-17-15-25-9-12-29-32-22(3)18-24-20-26(35)10-11-27(24)28(32)14-16-33(25,29)4;7-3(8)1-6(13,5(11)12)2-4(9)10/h8,10-11,13,19-20,22,25,28-29,32,35H,6-7,9,12,14-18,21H2,1-5H3;13H,1-2H2,(H,7,8)(H,9,10)(H,11,12)/t22-,25-,28-,29+,32-,33-;/m1./s1

SMILES Code: OC1=CC=C2[C@@]3([H])CC[C@]4(C)[C@@H](CCOC5=CC=C(C=C5OC)CN(CC)CC)CC[C@@]4([H])[C@]3([H])[C@H](C)CC2=C1.O=C(CC(C(O)=O)(O)CC(O)=O)O

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).

HS Tariff Code:


1: Inaji H, Iwata H, Nakayama T, Yamamoto N, Sato Y, Tokuda Y, Aogi K, Saji S, Watanabe K, Saito T, Yoshida M, Sato N, Saeki T, Takatsuka Y, Kuranami M, Yamashita H, Kikuchi A, Tabei T, Ikeda T, Noguchi S. Randomized phase II study of three doses of oral TAS-108 in postmenopausal patients with metastatic breast cancer. Cancer Sci. 2012 Sep;103(9):1708-13. doi: 10.1111/j.1349-7006.2012.02354.x. Epub 2012 Jul 16. PubMed PMID: 22676245.

2: Buzdar A, Vogel C, Schwartzberg L, Garin A, Perez A, Ingle J, Houghton M, Zergebel C, Kimball B. Randomized double-blind phase 2 trial of 3 doses of TAS-108 in patients with advanced or metastatic postmenopausal breast cancer. Cancer. 2012 Jul 1;118(13):3244-53. doi: 10.1002/cncr.26419. Epub 2011 Nov 1. PubMed PMID: 22045595.

3: Kumagai Y, Fujita T, Ozaki M, Yokota S, Maeda M, Shida M, Otani Y, Yamaya H, Tsuruta H. Safety, tolerability and pharmacokinetics of TAS-108, a novel anti-oestrogen, in healthy post-menopausal Japanese women: a phase I single oral dose study. Basic Clin Pharmacol Toxicol. 2009 May;104(5):352-9. doi: 10.1111/j.1742-7843.2008.00373.x. PubMed PMID: 19175362.

4: Saeki T, Noguchi S, Aogi K, Inaji H, Tabei T, Ikeda T. Evaluation of the safety and tolerability of oral TAS-108 in postmenopausal patients with metastatic breast cancer. Ann Oncol. 2009 May;20(5):868-73. doi: 10.1093/annonc/mdn714. Epub 2009 Jan 15. PubMed PMID: 19150935.

5: Yamaya H, Saeki M, Yoshida K, Shibata J, Yano S, Sato Y, Takao A, Shindo T, Buzdar AU, Nagayama S. Distribution of (7alpha)-21-[4-[(diethylamino) methyl]-2-methoxyphenoxy]-7-methyl-19-norpregna-1,3,5(10)-trien-3-ol-20-[14C]2-hy droxy-1,2,3-propanetricarboxylate ([14C]TAS-108) and its metabolites after single oral administration to rats bearing 7,12-dimethylbenz(alpha)anthracene-induced mammary tumor. Drug Metab Dispos. 2006 Feb;34(2):331-8. Epub 2005 Nov 18. PubMed PMID: 16299166.

6: Yamaya H, Yoshida K, Kuritani J, Yonezawa J, Tsuda M, Shindo T, Nagayama S, Buzdar AU. Safety, tolerability, and pharmacokinetics of TAS-108 in normal healthy post-menopausal female subjects: a phase I study on single oral dose. J Clin Pharm Ther. 2005 Oct;30(5):459-70. Erratum in: J Clin Pharm Ther. 2006 Apr;31(2):204. Yonezawa, JI [corrected to Yonezawa, J]. PubMed PMID: 16164493.

7: Buzdar AU. TAS-108: a novel steroidal antiestrogen. Clin Cancer Res. 2005 Jan 15;11(2 Pt 2):906s-8s. Review. PubMed PMID: 15701885.

8: Yamamoto Y, Shibata J, Yonekura K, Sato K, Hashimoto A, Aoyagi Y, Wierzba K, Yano S, Asao T, Buzdar AU, Terada T. TAS-108, a novel oral steroidal antiestrogenic agent, is a pure antagonist on estrogen receptor alpha and a partial agonist on estrogen receptor beta with low uterotrophic effect. Clin Cancer Res. 2005 Jan 1;11(1):315-22. PubMed PMID: 15671561.

9: Blakely LJ, Buzdar A, Chang HY, Frye D, Theriault R, Valero V, Rivera E, Booser D, Kuritani J, Tsuda M. A phase I and pharmacokinetic study of TAS-108 in postmenopausal female patients with locally advanced, locally recurrent inoperable, or progressive metastatic breast cancer. Clin Cancer Res. 2004 Aug 15;10(16):5425-31. PubMed PMID: 15328180.