Tacedinaline (GOE5549, PD123654, CI994; Acetyldinaline) is a potent, orally bioavailable and selective inhibitor of histone deacetylase 1/3 (HDAC1/3) with potential anticancer activity. It has IC50s of 0.9, 0.9, and 1.2 μM for HDAC1/2/3 inhibition, respectively.

Physicochemical Properties

Molecular Formula	C15H15N3O2
Molecular Weight	269.3
Exact Mass	269.116
Elemental Analysis	C, 66.90; H, 5.61; N, 15.60; O, 11.88
CAS #	112522-64-2
Related CAS #	112522-64-2
PubChem CID	2746
Appearance	Off-white solid powder
Density	1.3±0.1 g/cm3
Boiling Point	450.6±30.0 °C at 760 mmHg
Melting Point	242 °C(dec.)
Flash Point	226.3±24.6 °C
Vapour Pressure	0.0±1.1 mmHg at 25°C
Index of Refraction	1.707
LogP	0.96
Hydrogen Bond Donor Count	3
Hydrogen Bond Acceptor Count	3
Rotatable Bond Count	3
Heavy Atom Count	20
Complexity	351
Defined Atom Stereocenter Count	0
SMILES	O=C(C1C([H])=C([H])C(=C([H])C=1[H])N([H])C(C([H])([H])[H])=O)N([H])C1=C([H])C([H])=C([H])C([H])=C1N([H])[H]
InChi Key	VAZAPHZUAVEOMC-UHFFFAOYSA-N
InChi Code	InChI=1S/C15H15N3O2/c1-10(19)17-12-8-6-11(7-9-12)15(20)18-14-5-3-2-4-13(14)16/h2-9H,16H2,1H3,(H,17,19)(H,18,20)
Chemical Name	4-acetamido-N-(2-aminophenyl)benzamide
Synonyms	PD-123654; GOE-5549; Acetyldinaline; Tacedinaline; CI994; CI-994; CI 994; PD123654; PD-123654; PD 123654; N-acetyldinaline; Goe5549; Goe 5549
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	HD1 ( IC50 = 0.9 μM ); HD2 ( IC50 = 0.9 μM ); HD3 ( IC50 = 1.2 μM )
ln Vitro	In vitro activity: CI-994 (< 160 mM) exhibits cytostatic action in A-549 and LX-1 cells, along with an increase at the G0/G1 phase, a decrease at the S phase, and an increase in apoptosis.[2] With an IC50 of 7.4 μM, CI-994 inhibits LNCaP cell growth. CI-994 exhibits activity against multiple tumor cell lines, exhibiting higher cytotoxicity against solid tumors in comparison to leukemia and normal fibroblast cell lines.[4] With an IC50 of 2.5 μM, CI-994 suppresses the growth of rat leukemia BCLO cells.[5]
ln Vivo	CI-994 has exhibited antitumor activity against multiple tumor models, such as the human prostate tumor model LNCaP and the chemoresistant mouse pancreatic ductal carcinoma.[4]
Enzyme Assay	Tacedinaline, also known as N-acetyldinaline, has IC50 values of 0.9, 0.9, and 1.2 μM for recombinant HDAC 1, 2, and 3, respectively, making it an inhibitor of histone deacetylase (HDAC).
Cell Assay	The whole culture medium of RPMI 1640 medium, which includes 10% fetal bovine serum, 1% penicillin, and 1% streptomycin, is used to maintain LNCaP cell lines. 24-well plates are seeded with 2×104 cells, which are then incubated for one day at 37 °C in an incubator with 5% CO2. On days two and four, cultures are treated with CI-994 both alone and in combination. On days two and four, media are replaced and cells are cleaned. As a gauge of cell proliferation, mitochondrial metabolism is assessed by introducing 100 μL/well MTT (5 mg/mL in medium) and incubating it for two hours at 37 °C on Day 6. Dissolved crystals are placed in 500 μL of DMSO. At 560 nm, the absorbance is measured with a microplate reader. The percentage of cell proliferation is calculated from the absorbance data. Three duplicates of each assay are run.
Animal Protocol	Rats: Male rats are given single oral doses of acedinaline (CI-994) at 0, 10, 23, and 45 mg/kg to characterize its effects on lymphoid tissue.The rats are then killed up to 7 days after the last dose to assess the lymphoid tissue weights, bone marrow differentials, white blood cell differentials, and specific histopathology of the lymphoid tissue.
References	[1]. J Med Chem . 2007 Nov 15;50(23):5543-6. [2]. Oncol Res . 2005;15(1):39-48. [3].Bioorg Med Chem . 2008 Mar 15;16(6):3352-60. [4]. Invest New Drugs . 1996;14(4):349-56. [5]. Oncol Rep . 2008 Jun;19(6):1517-23.
Additional Infomation	Tacedinaline is a benzamide obtained by formal condensation of the carboxy group of 4-acetamidobenzoic acid with one of the amino groups of 1,2-phenylenediamine. An oral cytostatic drug with impressive differential activity against leukemic cells and normal stem-cells. Also used in combination therapy for selected tumors including non-smoll cell lung, pancreatic, breast, and colorectal cancers. It has a role as an EC 3.5.1.98 (histone deacetylase) inhibitor and an antineoplastic agent. It is a member of acetamides, a member of benzamides and a substituted aniline. It is functionally related to a 1,2-phenylenediamine. Tacedinaline has been used in trials studying the treatment of Lung Cancer, Multiple Myeloma, and Pancreatic Cancer. Acetyldinaline is under investigation in clinical trial NCT00005624 (CI-994 in Treating Patients With Advanced Myeloma). Tacedinaline is an orally bioavailable substituted benzamide derivative with potential antineoplastic activity. Tacedinaline inhibits histone deacetylation, which may result in histone hyperacetylation, followed by the induction of differentiation, the inhibition of cell proliferation, and apoptosis in susceptible tumor cell populations.

Solubility Data

Solubility (In Vitro)

DMSO: ~54 mg/mL (~200.5 mM) Water: <1 mg/mL Ethanol: <1 mg/mL

Solubility (In Vivo)

Solubility in Formulation 1: ≥ 2.5 mg/mL (9.28 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: 30% PEG400+0.5% Tween80+5% propylene glycol: 30mg/mL  (Please use freshly prepared in vivo formulations for optimal results.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	3.7133 mL	18.5667 mL	37.1333 mL
	5 mM	0.7427 mL	3.7133 mL	7.4267 mL
	10 mM	0.3713 mL	1.8567 mL	3.7133 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.