Toggle Nav

Pracinostat (SB939)

In stock
Catalog No.
Pan-HDAC inhibitor
Grouped product items
SizePriceStock Qty
10mM (in 1mL DMSO)
In stock
Evaluation Sample
In stock
In stock
In stock
In stock

Tel: +1-832-696-8203

Email: [email protected]

Worldwide Distributors

Pracinostat, also known as SB939, is a potent and orally available inhibitor of histone deacetylase (HDAC) with a relatively stronger selectivity (more than 1000-fold) for class I, class II and class IV HDACs rather than class III HDACs. Pracinostat potently suppresses proliferation in a wide range of cancer cell lines, including colon cancer, ovarian cancer, prostate carcinomas, acute myeloid leukaemia (AML) and B cell lymphoma. Recent study results have shown that SB939 induces the accumulation of acetylated histone H3 (AcH3) and acetylated α-tubulin and increases the expression of the cyclin dependent kinase inhibitor p21 in cancer cells.


Razak AR, Hotte SJ, Siu LL, Chen EX, Hirte HW, Powers J, Walsh W, Stayner LA, Laughlin A, Novotny-Diermayr V, Zhu J, Eisenhauer EA. Phase I clinical, pharmacokinetic and pharmacodynamic study of SB939, an oral histone deacetylase (HDAC) inhibitor, in patients with advanced solid tumours. Br J Cancer. 2011;104(5):756-762.

Product Citation

Chemical Properties

Physical AppearanceA solid
StorageStore at -20°C
Cas No.929016-96-6
SynonymsSB-939, SB 939
Solubility≥11.4 mg/mL in DMSO, ≥24.8 mg/mL in EtOH with ultrasonic, <2.5 mg/mL in H2O
Chemical Name(E)-3-[2-butyl-1-[2-(diethylamino)ethyl]benzimidazol-5-yl]-N-hydroxyprop-2-enamide
SDFDownload SDF
Shipping ConditionEvaluation sample solution : ship with blue ice.All other available size: ship with RT , or blue ice upon request
General tipsFor obtaining a higher solubility , please warm the tube at 37 ℃ and shake it in the ultrasonic bath for a while.Stock solution can be stored below -20℃ for several months.


Cell experiment:

Cell lines

Ovarian (A2780) , colon (HCT-116), and prostate (PC-3) cell lines

Preparation method

The solubility of this compound in DMSO is >10 mM. General tips for obtaining a higher concentration: Please warm the tube at 37 °C for 10 minutes and/or shake it in the ultrasonic bath for a while.Stock solution can be stored below -20°C for several months.

Reaction Conditions

96 h; IC50=0.48±0.21 μM (A2780), 0.48±0.27 μM (HCT-116), 0.34±0.06 μM (PC-3)


SB939 showed broad anti-proliferative activity against representative tumor cells from ovarian (A2780) , colon (HCT-116), and prostate (PC-3) with cellular IC50 values of 0.48±0.21, 0.48±0.27 and 0.34±0.06 μM, respectively.

Animal experiment:

Animal models

Athymic nude mice

Dosage form

200 mg/kg, 100 mg/kg, 50 mg/kg; oral taken.


SB939 was clearly toxic at the highest dose tested (200 mg/kg); however, at the MTD dose of 100 mg/kg and at 50mg/kg, it demonstrated very significant antitumor effects on day 21 with TGI = 90% (p < 0.001 ) and 66% ( p < 0.001), respectively, with acceptable body weight loss.

Other notes

Please test the solubility of all compounds indoor, and the actual solubility may slightly differ with the theoretical value. This is caused by an experimental system error and it is normal.


[1] Wang H, Yu N, Chen D, et al. Discovery of (2 E)-3-{2-butyl-1-[2-(diethylamino) ethyl]-1 H-benzimidazol-5-yl}-N-hydroxyacrylamide (SB939), an orally active histone deacetylase inhibitor with a superior preclinical profile[J]. Journal of medicinal chemistry, 2011, 54(13): 4694-4720.

Biological Activity

Description Pracinostat (SB939) is a potent inhibitor of HDAC with IC50 of 40-140 nM with exception for HDAC6.
IC50 49 nM 43 nM 56 nM 47 nM 70 nM 40 nM

Quality Control

Chemical structure

Pracinostat (SB939)

Related Biological Data

Pracinostat (SB939)

Related Biological Data

Pracinostat (SB939)

Related Biological Data

Pracinostat (SB939)

Related Biological Data

Pracinostat (SB939)

Research Update

1. Antimalarial activity of the anticancer histone deacetylase inhibitor SB939. Antimicrob Agents Chemother. 2012 Jul;56(7):3849-56. doi: 10.1128/AAC.00030-12. Epub 2012 Apr 16.
SB939 is a HDAC that potently inhibited the growth of multiple malarial parasites at different life stages.
2. Preclinical metabolism and disposition of SB939 (Pracinostat), an orally active histone deacetylase inhibitor, and prediction of human pharmacokinetics. Drug Metab Dispos. 2011 Dec;39(12):2219-32. doi: 10.1124/dmd.111.041558. Epub 2011 Aug 26.
The preclinical ADME properties of SB939, a orally active HDAC inhibitor primarily metabolized by CYP3A4 and CYP1A2 in human, have been characterized in human and animals, where observed ADME of SB939 in human were consistent with predication s by Simcyp and allometric scaling.
4. A phase I study of histone deacetylase inhibitor, pracinostat (SB939), in pediatric patients with refractory solid tumors: IND203 a trial of the NCIC IND program/C17 pediatric phase I consortium. Pediatr Blood Cancer. 2013 Nov;60(11):1868-74. doi: 10.1002/pbc.24694. Epub 2013 Jul 25.
With a RP2D of 60 mg po t.i.w. for 3 weeks every 4 weeks in adult patients, the toxicities, PKs and RP2D of SB939, an inhibitor of class 1/2/4 HDAC, have been investigated in children with refractory solid tumors.
5. Pharmacodynamic evaluation of the target efficacy of SB939, an oral HDAC inhibitor with selectivity for tumor tissue. Mol Cancer Ther. 2011 Jul;10(7):1207-17. doi: 10.1158/1535-7163.MCT-11-0044. Epub 2011 May 17.
SB939, an inhibitor of class 1/2/4 HDACs, exhibited favorable PKs and PDs in preclinical models leading to successful applications to patients, where SB939 dose- and time-dependently induced acH3 accumulation in cancerous tissues and leukemic bone marrow.