ARQ 621 (ARQ-621; ARQ621) is an allosteric Eg5 mitotic motor protein inhibitor with potential anticancer activity. Eg5 is overexpressed in many cancer tumors and is important for the dynamic organization of the mitotic spindle, thus has become an excellent target of anticancer therapeutics.

Physicochemical Properties

Molecular Formula	C28H24CL2FN5O2
Molecular Weight	552.43
Exact Mass	551.129
CAS #	1095253-39-6
Related CAS #	1095253-39-6
PubChem CID	25110841
Appearance	White to off-white solid powder
Density	1.3±0.1 g/cm3
Boiling Point	730.6±70.0 °C at 760 mmHg
Flash Point	395.7±35.7 °C
Vapour Pressure	0.0±2.4 mmHg at 25°C
Index of Refraction	1.638
LogP	4.18
Hydrogen Bond Donor Count	2
Hydrogen Bond Acceptor Count	6
Rotatable Bond Count	9
Heavy Atom Count	38
Complexity	920
Defined Atom Stereocenter Count	1
SMILES	C#CC[C@H](C1=NC2=C(C=CC(=C2)Cl)C(=O)N1NC3=CC=CC=C3)N(CCCN)C(=O)C4=C(C(=CC=C4)Cl)F
InChi Key	UPJSUQWHUVLLNW-XMMPIXPASA-N
InChi Code	InChI=1S/C28H24Cl2FN5O2/c1-2-8-24(35(16-7-15-32)27(37)21-11-6-12-22(30)25(21)31)26-33-23-17-18(29)13-14-20(23)28(38)36(26)34-19-9-4-3-5-10-19/h1,3-6,9-14,17,24,34H,7-8,15-16,32H2/t24-/m1/s1
Chemical Name	(R)-N-(3-aminopropyl)-3-chloro-N-(1-(7-chloro-4-oxo-3-(phenylamino)-3,4-dihydroquinazolin-2-yl)but-3-yn-1-yl)-2-fluorobenzamide
Synonyms	ARQ621; ARQ 621; ARQ-621
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 Note: This product requires protection from light (avoid light exposure) during transportation and storage.
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

ln Vitro	Eg5 is a putative anti-cancer target since over-expression of the protein results in genomic instability and tumor development in mice[1].
ln Vivo	ARQ 621, as a novel clinical stage drug candidate, inhibits a number of xenografts grown in athymic mice, such as pancreatic, breast, prostate, and ovarian carcinomas with no hematological changes. Furthermore, for ARQ 621, there is no envidence of bone marrow toxicity in pre-clinical mouse efficacy models or safety studies in rats and dogs.
Animal Protocol
References	[1]. First-in-human study with ARQ 621, a novel inhibitor of Eg5: Final results from the solid tumors cohort.J Clin Oncol. 2011, May (20): 3076-3076. [2]. Mapping Novel Metabolic Nodes Targeted by Anti-Cancer Drugs that Impair Triple-Negative Breast Cancer Pathogenicity. ACS Chem Biol. 2017 Apr 21;12(4):1133-1140.
Additional Infomation	Eg5 Kinesin-Related Motor Protein Inhibitor ARQ 621 is a small-molecule inhibitor of the kinesin-related motor protein Eg5 with potential antineoplastic activity. Eg5 kinesin-related motor protein inhibitor ARQ 621 selectively inhibits the activity of Eg5, which may result in mitotic disruption, apoptosis and cell death. The ATP-dependent Eg5 kinesin-related motor protein (also known as KIF11 or kinesin spindle protein-5) is a plus-end directed kinesin motor protein involved in the regulation of spindle dynamics, including assembly and maintenance, during mitosis.

Solubility Data

Solubility (In Vitro)

DMSO: 100 mg/mL (181.0 mM) Water:<1 mg/mL Ethanol:100 mg/mL (181.0 mM)

Solubility (In Vivo)

Note: Listed below are some common formulations that may be used to formulate products with low water solubility (e.g. < 1 mg/mL), you may test these formulations using a minute amount of products to avoid loss of samples. Injection Formulations (e.g. IP/IV/IM/SC) Injection Formulation 1: DMSO : Tween 80： Saline = 10 : 5 : 85 (i.e. 100 μL DMSO stock solution → 50 μL Tween 80 → 850 μL Saline) *Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH ₂ O to obtain a clear solution. Injection Formulation 2: DMSO : PEG300 ：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL DMSO → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline) Injection Formulation 3: DMSO : Corn oil = 10 : 90 (i.e. 100 μL DMSO → 900 μL Corn oil) Example: Take the Injection Formulation 3 (DMSO : Corn oil = 10 : 90) as an example, if 1 mL of 2.5 mg/mL working solution is to be prepared, you can take 100 μL 25 mg/mL DMSO stock solution and add to 900 μL corn oil, mix well to obtain a clear or suspension solution (2.5 mg/mL, ready for use in animals). Injection Formulation 4: DMSO : 20% SBE-β-CD in saline = 10 : 90 [i.e. 100 μL DMSO → 900 μL (20% SBE-β-CD in saline)] *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. Injection Formulation 5: 2-Hydroxypropyl-β-cyclodextrin : Saline = 50 : 50 (i.e. 500 μL 2-Hydroxypropyl-β-cyclodextrin → 500 μL Saline) Injection Formulation 6: DMSO : PEG300 : castor oil : Saline = 5 : 10 : 20 : 65 (i.e. 50 μL DMSO → 100 μLPEG300 → 200 μL castor oil → 650 μL Saline) Injection Formulation 7: Ethanol : Cremophor : Saline = 10： 10 : 80 (i.e. 100 μL Ethanol → 100 μL Cremophor → 800 μL Saline) Injection Formulation 8: Dissolve in Cremophor/Ethanol (50 : 50), then diluted by Saline Injection Formulation 9: EtOH : Corn oil = 10 : 90 (i.e. 100 μL EtOH → 900 μL Corn oil) Injection Formulation 10: EtOH : PEG300：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL EtOH → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline) Oral Formulations Oral Formulation 1: Suspend in 0.5% CMC Na (carboxymethylcellulose sodium) Oral Formulation 2: Suspend in 0.5% Carboxymethyl cellulose Example: Take the Oral Formulation 1 (Suspend in 0.5% CMC Na) as an example, if 100 mL of 2.5 mg/mL working solution is to be prepared, you can first prepare 0.5% CMC Na solution by measuring 0.5 g CMC Na and dissolve it in 100 mL ddH2O to obtain a clear solution; then add 250 mg of the product to 100 mL 0.5% CMC Na solution, to make the suspension solution (2.5 mg/mL, ready for use in animals). Oral Formulation 3: Dissolved in PEG400 Oral Formulation 4: Suspend in 0.2% Carboxymethyl cellulose Oral Formulation 5: Dissolve in 0.25% Tween 80 and 0.5% Carboxymethyl cellulose Oral Formulation 6: Mixing with food powders Note: Please be aware that the above formulations are for reference only. InvivoChem strongly recommends customers to read literature methods/protocols carefully before determining which formulation you should use for in vivo studies, as different compounds have different solubility properties and have to be formulated differently.  (Please use freshly prepared in vivo formulations for optimal results.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	1.8102 mL	9.0509 mL	18.1018 mL
	5 mM	0.3620 mL	1.8102 mL	3.6204 mL
	10 mM	0.1810 mL	0.9051 mL	1.8102 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.