Domatinostat (formerly 4SC-202) is a novel, potent, and orally bioavailable benzamide-based Class I HDAC inhibitor with potential anticancer activity. It has IC50 values of 1.20 μM, 1.12 μM, and 0.57 μM for HDAC1, HDAC2, and HDAC3 inhibition, respectively. In order to cause an accumulation of highly acetylated histones, domatinostat/4SC-202 selectively binds to and inhibits class I HDACs.

Physicochemical Properties

Molecular Formula	C23H21N5O3S
Molecular Weight	447.51
Exact Mass	447.136
Elemental Analysis	C, 61.73; H, 4.73; N, 15.65; O, 10.73; S, 7.17
CAS #	910462-43-0
Related CAS #	1186222-89-8
PubChem CID	15985904
Appearance	White to khaki solid powder
Density	1.3±0.1 g/cm3
Index of Refraction	1.672
LogP	2.63
Hydrogen Bond Donor Count	2
Hydrogen Bond Acceptor Count	5
Rotatable Bond Count	6
Heavy Atom Count	32
Complexity	775
Defined Atom Stereocenter Count	0
SMILES	S(C1C=CC(C2C=NN(C)C=2)=CC=1)(N1C=CC(/C=C/C(=O)NC2C=CC=CC=2N)=C1)(=O)=O
InChi Key	PRXXYMVLYKJITB-IZZDOVSWSA-N
InChi Code	InChI=1S/C23H21N5O3S/c1-27-16-19(14-25-27)18-7-9-20(10-8-18)32(30,31)28-13-12-17(15-28)6-11-23(29)26-22-5-3-2-4-21(22)24/h2-16H,24H2,1H3,(H,26,29)/b11-6+
Chemical Name	(E)-N-(2-aminophenyl)-3-[1-[4-(1-methylpyrazol-4-yl)phenyl]sulfonylpyrrol-3-yl]prop-2-enamide
Synonyms	domatinostat; 4SC202; 4SC 202; 4SC-202
HS Tariff Code	2934.99.9001
Storage	Powder-20°C 3 years 4°C 2 years In solvent -80°C 6 months -20°C 1 month
Shipping Condition	Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Biological Activity

Targets	HDAC-3 ( IC50 = 0.57 μM ); HDAC-2 ( IC50 = 1.12 μM ); HDAC-1 ( IC50 = 1.2 μM ); HDAC-11 ( IC50 = 9.7 μM ); HDAC-5 ( IC50 = 11.3 μM ); HDAC-10 ( IC50 = 21 μM ); HDAC-9 ( IC50 = 50 μM )
ln Vitro	4SC-202 has an EC50 of 1.1 μM and causes hyperacetylation of histone H3 in HeLa cells. By interfering with the mitotic spindle's normal development and resulting in a collapsed spindle apparatus and multiple nucleation centers, 4SC-202 induces a G2/M cell cycle arrest. Furthermore, 4SC-202 exhibits a broad anti-proliferative activity with a mean IC50 of 0.7 μM against human cancer cell lines.[1]
ln Vivo	4SC-202 exhibits strong metabolic stability, low plasma clearance, and high oral bioavailability in vivo. In both the RKO27 colon carcinoma model and the A549 NSCLC xenograft, 4SC-202 (120 mg/kg p.o.) exhibits strong and noticeable anti-tumor activity.[1]
Cell Assay	Treatment with domatinostat (4SC-202 free base) tosylate has strong cytotoxic and proliferation-inhibitory effects on patient-derived primary HCC cells as well as established HCC cell lines (HepG2, HepB3, SMMC-7721). As a result of the activation of apoptosis signal-regulating kinase 1 (ASK1) induced by domatinostat (4SC-202 free base), it translocates to mitochondria and physically associates with Cyp-D.
Animal Protocol	A549 NSCLC xenograft model and RKO27 colon carcinoma model 120 mg/kg p.o.
References	[1]. 22nd EORTC-NCI-AACR symposium. 2010. Abstract # 178. [2]. Tumour Biol . 2016 Aug;37(8):10257-67.
Additional Infomation	4SC-202 has been used in trials studying the treatment of Advanced Hematologic Malignancies. Domatinostat is an orally bioavailable benzamide and inhibitor of human class I histone deacetylases (HDACs) isoenzymes 1, 2 and 3, with potential antineoplastic activity. Domatinostat selectively binds to and inhibits class I HDACs leading to an accumulation of highly acetylated histones. This may result in an induction of chromatin remodeling, the selective transcription of tumor suppressor genes, and the tumor suppressor protein-mediated inhibition of tumor cell division and eventually the induction of tumor cell apoptosis. This may inhibit tumor cell proliferation in susceptible tumor cells. HDACs, upregulated in many tumor types, are a class of enzymes that deacetylate chromatin histone proteins.

Solubility Data

Solubility (In Vitro)

DMSO: ~89 mg/mL (~198.9 mM) Water: <1 mg/mL Ethanol: <1 mg/mL

Solubility (In Vivo)

Solubility in Formulation 1: ≥ 2.5 mg/mL (5.59 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% 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 25.0 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. Solubility in Formulation 2: ≥ 2.5 mg/mL (5.59 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 25.0 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. Solubility in Formulation 3: 2% DMSO+30% PEG 300+5% Tween 80+ddH2O: 10 mg/mL  (Please use freshly prepared in vivo formulations for optimal results.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	2.2346 mL	11.1729 mL	22.3459 mL
	5 mM	0.4469 mL	2.2346 mL	4.4692 mL
	10 mM	0.2235 mL	1.1173 mL	2.2346 mL

*Note: Please select an appropriate solvent for the preparation of stock solution based on your experiment needs. For most products, DMSO can be used for preparing stock solutions (e.g. 5 mM, 10 mM, or 20 mM concentration); some products with high aqueous solubility may be dissolved in water directly. Solubility information is available at the above Solubility Data section. Once the stock solution is prepared, aliquot it to routine usage volumes and store at -20°C or -80°C. Avoid repeated freeze and thaw cycles.