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

MedKoo CAT#: 201266

CAS#: 209783-80-2

Description: Entinostat, also known as MS-275 or SNDX-275, is a potent HDAC inhibitor with potential antineoplastic activity. Entinostat binds to and inhibits histone deacetylase, an enzyme that regulates chromatin structure and gene transcription. This agent appears to exert dose-dependent effects in human leukemia cells including cyclin-dependent kinase inhibitor 1A (p21/CIP1/WAF1)-dependent growth arrest and differentiation at low drug concentrations; a marked induction of reactive oxygen species (ROS); mitochondrial damage; caspase activation; and, at higher concentrations, apoptosis.

Chemical Structure

CAS# 209783-80-2

Theoretical Analysis

MedKoo Cat#: 201266
Name: Entinostat
CAS#: 209783-80-2
Chemical Formula: C21H20N4O3
Exact Mass: 376.15354
Molecular Weight: 376.41
Elemental Analysis: C, 67.01; H, 5.36; N, 14.88; O, 12.75

Price and Availability

Size Price Availability Quantity
100.0mg USD 150.0 Ready to ship
200.0mg USD 190.0 Ready to ship
500.0mg USD 350.0 2 Weeks
1.0g USD 650.0 2 Weeks
2.0g USD 950.0 2 Weeks
5.0g USD 2150.0 2 Weeks
10.0g USD 3650.0 2 weeks
20.0g USD 4950.0 2 weeks
10.0mM * 1 mL DMSO USD 190.0 2 Weeks
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Synonym: MS275; MS-275; MS 2275; SNDX275; SNDX-275; SNDX 275; Entinostat

IUPAC/Chemical Name: pyridin-3-ylmethyl 4-((2-aminophenyl)carbamoyl)benzylcarbamate.


InChi Code: InChI=1S/C21H20N4O3/c22-18-5-1-2-6-19(18)25-20(26)17-9-7-15(8-10-17)13-24-21(27)28-14-16-4-3-11-23-12-16/h1-12H,13-14,22H2,(H,24,27)(H,25,26)


Appearance: white off white solid powder

Purity: >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).

Solubility: 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: 2934.99.9001

Solubility Data

Solvent Max Conc. mg/mL Max Conc. mM
DMSO 30.0 79.7

Preparing Stock Solutions

The following data is based on the product molecular weight 376.41 Batch specific molecular weights may vary from batch to batch due to the degree of hydration, which will affect the solvent volumes required to prepare stock solutions.

Recalculate based on batch purity %
Concentration / Solvent Volume / Mass 1 mg 5 mg 10 mg
1 mM 1.15 mL 5.76 mL 11.51 mL
5 mM 0.23 mL 1.15 mL 2.3 mL
10 mM 0.12 mL 0.58 mL 1.15 mL
50 mM 0.02 mL 0.12 mL 0.23 mL

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1: Schech AJ, Shah P, Yu S, Sabnis GJ, Goloubeva O, Rosenblatt P, Kazi A, Chumsri S, Brodie A. Histone deacetylase inhibitor entinostat in combination with a retinoid downregulates HER2 and reduces the tumor initiating cell population in aromatase inhibitor-resistant breast cancer. Breast Cancer Res Treat. 2015 Jul 2. [Epub ahead of print] PubMed PMID: 26133921.

2: Ruiz R, Raez LE, Rolfo C. Entinostat (SNDX-275) for the treatment of non-small cell lung cancer. Expert Opin Investig Drugs. 2015 Aug;24(8):1101-9. doi: 10.1517/13543784.2015.1056779. Epub 2015 Jun 22. PubMed PMID: 26098363.

3: Schech A, Kazi A, Yu S, Shah P, Sabnis G. Histone Deacetylase Inhibitor Entinostat Inhibits Tumor-Initiating Cells in Triple-Negative Breast Cancer Cells. Mol Cancer Ther. 2015 Jun 2. [Epub ahead of print] PubMed PMID: 26037781.

4: Frys S, Simons Z, Hu Q, Barth MJ, Gu JJ, Mavis C, Skitzki J, Song L, Czuczman MS, Hernandez-Ilizaliturri FJ. Entinostat, a novel histone deacetylase inhibitor is active in B-cell lymphoma and enhances the anti-tumour activity of rituximab and chemotherapy agents. Br J Haematol. 2015 May;169(4):506-19. doi: 10.1111/bjh.13318. Epub 2015 Feb 23. PubMed PMID: 25712263.

5: Vendetti FP, Topper M, Huang P, Dobromilskaya I, Easwaran H, Wrangle J, Baylin SB, Poirier JT, Rudin CM. Evaluation of azacitidine and entinostat as sensitization agents to cytotoxic chemotherapy in preclinical models of non-small cell lung cancer. Oncotarget. 2015 Jan 1;6(1):56-70. PubMed PMID: 25474141; PubMed Central PMCID: PMC4381578.

6: Ngamphaiboon N, Dy GK, Ma WW, Zhao Y, Reungwetwattana T, DePaolo D, Ding Y, Brady W, Fetterly G, Adjei AA. A phase I study of the histone deacetylase (HDAC) inhibitor entinostat, in combination with sorafenib in patients with advanced solid tumors. Invest New Drugs. 2015 Feb;33(1):225-32. doi: 10.1007/s10637-014-0174-6. Epub 2014 Nov 5. PubMed PMID: 25371323.

7: Lee J, Bartholomeusz C, Mansour O, Humphries J, Hortobagyi GN, Ordentlich P, Ueno NT. A class I histone deacetylase inhibitor, entinostat, enhances lapatinib efficacy in HER2-overexpressing breast cancer cells through FOXO3-mediated Bim1 expression. Breast Cancer Res Treat. 2014 Jul;146(2):259-72. doi: 10.1007/s10549-014-3014-7. Epub 2014 Jun 12. PubMed PMID: 24916181; PubMed Central PMCID: PMC4119423.

8: Yang X, Zhang Q, Chen M, Hu L. Pharmacokinetic interaction of entinostat and lapatinib following single and co-oral administration in rats. Xenobiotica. 2014 Nov;44(11):1009-13. doi: 10.3109/00498254.2014.919431. Epub 2014 May 16. PubMed PMID: 24831712.

9: Tellez CS, Grimes MJ, Picchi MA, Liu Y, March TH, Reed MD, Oganesian A, Taverna P, Belinsky SA. SGI-110 and entinostat therapy reduces lung tumor burden and reprograms the epigenome. Int J Cancer. 2014 Nov 1;135(9):2223-31. doi: 10.1002/ijc.28865. Epub 2014 Apr 5. PubMed PMID: 24668305.

10: Prebet T, Sun Z, Figueroa ME, Ketterling R, Melnick A, Greenberg PL, Herman J, Juckett M, Smith MR, Malick L, Paietta E, Czader M, Litzow M, Gabrilove J, Erba HP, Gore SD, Tallman MS. Prolonged administration of azacitidine with or without entinostat for myelodysplastic syndrome and acute myeloid leukemia with myelodysplasia-related changes: results of the US Leukemia Intergroup trial E1905. J Clin Oncol. 2014 Apr 20;32(12):1242-8. doi: 10.1200/JCO.2013.50.3102. Epub 2014 Mar 24. PubMed PMID: 24663049; PubMed Central PMCID: PMC3986386.


100.0mg / USD 150.0

Additional Information

Entinostat inhibits class I HDAC1 and HDAC3 with IC50 of 0.51 μM and 1.7 μM, respectively.  Entinostat  preferentially inhibits cell proliferation/survival and inactivates downstream signaling in erbB2-overexpressing compared with basal breast cancer cells. Entinostat  reduces the levels of both erbB2 and erbB3, as well as significantly decreases P-erbB2, P-erbB3, P-Akt, and P-MAPK in erbB2-overexpressing cells. Additionally, Entinostat promotes apoptosis and induces cell cycle arrest predominantly at G(1) phase in erbB2-overexpressing cells, whereas Entinostat  mainly induces G(2)-M arrest in basal breast cancer cells. The cellular bias of Entinostat  is shown to be related partly to the levels of erbB3 expression that directly impact the ability of Entinostat  to inhibit proliferation/survival of the erbB2-overexpressing breast cancer cells. These findings show that Entinostat may be developed as a novel therapeutic agent to treat breast cancers with coexpression of both erbB2 and erbB3. see http://www.ncbi.nlm.nih.gov/pubmed/19826038.
Entinostat is an orally bioavailable, selective, class I histone deacetylase (HDAC) inhibitor. Entinostat is currently being investigated in randomized, Phase 2 clinical studies in combination with the aromatase inhibitor, exemestane, for the treatment of metastatic or locally advanced ER+ breast cancer; in combination with erlotinib in advanced non-small-cell lung cancer, and in combination with azacitidine in myelodysplastic syndrome. Phase 2 single arm studies in non-small cell lung cancer and colorectal cancer, also are being conducted in combination with azacitidine; and a Phase 2 in Hodgkin's lymphoma is ongoing with single agent entinostat. Entinostat's long half-life allows for weekly or every-other-week oral dosing.