CR8 is a novel and potent inhibitor of CDK with anticancer and neuroprotective effects. As a second-generation analog of Roscovitine, (R)-CR8 (CR8) inhibits CDK1/cyclin B (IC50=0.09 μM), CDK2/cyclin A (0.072 μM), CDK2/cyclin E (0.041 μM), CDK5/p25 (0.11 μM), CDK7/cyclin H (1.1 μM), CDK9/cyclin T (0.18 μM) and CK1δ/ε (0.4 μM).
Physicochemical Properties
| Molecular Formula | C24H29N7O |
| Molecular Weight | 431.53 |
| Exact Mass | 431.243 |
| CAS # | 294646-77-8 |
| Related CAS # | (S)-CR8;1084893-56-0;(R)-CR8 trihydrochloride;1786438-30-9 |
| PubChem CID | 10224714 |
| Appearance | White to off-white solid powder |
| Density | 1.3±0.1 g/cm3 |
| Boiling Point | 671.4±65.0 °C at 760 mmHg |
| Flash Point | 359.8±34.3 °C |
| Vapour Pressure | 0.0±2.2 mmHg at 25°C |
| Index of Refraction | 1.664 |
| LogP | 2.1 |
| Hydrogen Bond Donor Count | 3 |
| Hydrogen Bond Acceptor Count | 7 |
| Rotatable Bond Count | 9 |
| Heavy Atom Count | 32 |
| Complexity | 557 |
| Defined Atom Stereocenter Count | 1 |
| SMILES | CC[C@H](CO)NC1=NC(=C2C(=N1)N(C=N2)C(C)C)NCC3=CC=C(C=C3)C4=CC=CC=N4 |
| InChi Key | HOCBJBNQIQQQGT-LJQANCHMSA-N |
| InChi Code | InChI=1S/C24H29N7O/c1-4-19(14-32)28-24-29-22(21-23(30-24)31(15-27-21)16(2)3)26-13-17-8-10-18(11-9-17)20-7-5-6-12-25-20/h5-12,15-16,19,32H,4,13-14H2,1-3H3,(H2,26,28,29,30)/t19-/m1/s1 |
| Chemical Name | (2R)-2-[[9-propan-2-yl-6-[(4-pyridin-2-ylphenyl)methylamino]purin-2-yl]amino]butan-1-ol |
| Synonyms | CR 8 CR-8 CR8 |
| 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 | (R)-CR8 (CR8) (0.1-100 μM; 48 hours) is a strong inducer of apoptosis with an IC50 of 0.49 μM in SH-SY5Y cell line [1]. (R)-CR8 (0.25-10 μM) promotes dose-dependent cleavage of poly(ADP-ribose) polymerase (PARP) [1]. The CDK-bound version of (R)-CR8 possesses a solvent-exposed pyridyl moiety that stimulates complex formation between CDK12-cyclin K and the CUL4 adaptor protein DDB1, bypassing the need for substrate receptors and presenting to the cell cycle Protein K suffers ubiquitination and destruction [3]. |
| ln Vivo | (R)-CR8 (5 mg/Kg; intraperitoneal injection) significantly reduced the size of the lesion at 28 days in histological examination [2]. |
| Cell Assay |
Apoptosis analysis [1] Cell Types: SH-SY5Y Cell line Tested Concentrations: 0.1, 1, 10, 100 μM Incubation Duration: 24 hrs (hours) Experimental Results: Cell survival rate diminished in a dose-dependent manner. |
| Animal Protocol |
Animal/Disease Models: Adult (10 to 12 weeks old) male SD (SD (Sprague-Dawley)) rats (310 to 330 g) [2] Doses: ip Route of Administration: 5 mg/Kg Experimental Results: Results in a significant reduction in lesion size. |
| References |
[1]. CR8, a potent and selective, roscovitine-derived inhibitor of cyclin-dependent kinases. Oncogene. 2008 Oct 2;27(44):5797-807. [2]. CR8, a novel inhibitor of CDK, limits microglial activation, astrocytosis, neuronal loss, and neurologic dysfunction after experimental traumatic brain injury. J Cereb Blood Flow Metab. 2014 Mar;34(3):502-13. [3]. The CDK inhibitor CR8 acts as a molecular glue degrader that depletes cyclin K [published online ahead of print, 2020 Jun 3]. Nature. 2020;10.1038/s41586-020-2374-x. |
Solubility Data
| Solubility (In Vitro) | DMSO : ~50 mg/mL (~115.87 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 | 2.3173 mL | 11.5867 mL | 23.1734 mL | |
| 5 mM | 0.4635 mL | 2.3173 mL | 4.6347 mL | |
| 10 mM | 0.2317 mL | 1.1587 mL | 2.3173 mL |