KF21213 binds selectively to the adenosine A2A receptor with Ki of 3.0 nM.

Physicochemical Properties

Molecular Formula	C19H22N4O3
Molecular Weight	354.40298
Exact Mass	354.169
CAS #	155271-17-3
PubChem CID	6448866
Appearance	Typically exists as solid at room temperature
Density	1.24g/cm3
Boiling Point	583ºC at 760mmHg
Flash Point	306.4ºC
Vapour Pressure	1.4E-13mmHg at 25°C
Index of Refraction	1.612
LogP	1.766
Hydrogen Bond Donor Count	0
Hydrogen Bond Acceptor Count	4
Rotatable Bond Count	3
Heavy Atom Count	26
Complexity	595
Defined Atom Stereocenter Count	0
SMILES	N1(C)C2=C(N(C)C(=O)N(C)C2=O)N=C1/C=C/C1=CC=C(OC)C(C)=C1C
InChi Key	SDHWMROLJYZHCX-CSKARUKUSA-N
InChi Code	InChI=1S/C19H22N4O3/c1-11-12(2)14(26-6)9-7-13(11)8-10-15-20-17-16(21(15)3)18(24)23(5)19(25)22(17)4/h7-10H,1-6H3/b10-8+
Chemical Name	8-[(E)-2-(4-methoxy-2,3-dimethylphenyl)ethenyl]-1,3,7-trimethylpurine-2,6-dione
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

ln Vitro	[11C]KF21213 acts as a PET ligand for mapping adenosine A2A receptors in the central nervous system (CNS). KF21213 possesses significant affinity for the adenosine A2A receptor in vitro (Ki=3.0 nM) and very low affinity for the A1 receptor (Ki>10,000 nM) [1].
ln Vivo	The first fifteen minutes saw a steady increase in the striatal absorption of [11C]KF21213, which subsequently declined. Following injection, cortical and cerebellar uptake quickly decreased. Their concentrations match those found in the blood. As a result, during the course of 60 minutes (N=4), the striatal-to-cortical and striatal-to-cerebellar uptake ratios increased to 8.6±1.6 and 10.5±2.1, respectively. While the striatal activity level of [11C]KF18446 immediately declined, the striatal activity level of [11C]KF21213 stayed steady for the first five minutes and then gradually reduced over time. For both ligands, cerebellar activity rapidly dropped. Uptake from striatum to cerebellum: While the ratio of [11C]KF18446 increased during the first 10 minutes and was constant (1.4± 0.3, N=3, during 25–35 minutes), the ratio of [11C]KF21213 increased steadily over 50–60 minutes to 2.4 6 0.5 (N 5 3) [1].
References	[1]. Wang WF, et al. Carbon-11-labeled KF21213: a highly selective ligand for mapping CNS adenosine A(2A) receptors with positron emission tomography. Nucl Med Biol. 2000 Aug;27(6):541-6

Solubility Data

Solubility (In Vitro)

May dissolve in DMSO (in most cases), if not, try other solvents such as H2O, Ethanol, or DMF with a minute amount of products to avoid loss of samples

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	2.8217 mL	14.1084 mL	28.2167 mL
	5 mM	0.5643 mL	2.8217 mL	5.6433 mL
	10 mM	0.2822 mL	1.4108 mL	2.8217 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.