A CTD kinase inhibitor
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DRB

Item No. 10010302

Product Insert (PDF)Safety Data Sheet (SDS) (PDF)
Technical Information
Formal Name
5,6-dichloro-1-β-D-ribofuranosyl-1H-benzimidazole
CAS Number
53-85-0
Synonyms
  • Benzimidazole
  • NSC 401575
Molecular Formula
C12H12Cl2N2O4
Formula Weight
319.1
Purity
≥98%
Formulation (Request formulation change)
A crystalline solid
Solubility(Learn about Variance in Solubility)
DMF: 10 mg/mlDMF:PBS (pH 7.2) (1:2): 0.3 mg/mlDMSO: 10 mg/mlEthanol: 0.5 mg/ml
λmax
214 nm
SMILES
O[C@@H]1[C@H](O)[C@@H](CO)O[C@H]1N2C=NC3=C2C=C(Cl)C(Cl)=C3
InChi Code
InChI=1S/C12H12Cl2N2O4/c13-5-1-7-8(2-6(5)14)16(4-15-7)12-11(19)10(18)9(3-17)20-12/h1-2,4,9-12,17-19H,3H2/t9-,10-,11-,12-/m1/s1
InChi Key
XHSQDZXAVJRBMX-DDHJBXDOSA-N
Shipping & Storage Information
Storage
-20°C
Shipping
Room temperature in continental US; may vary elsewhere
Certificates of Analysis & Batch Specific Data

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    10 mg

    $35

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    50 mg

    $147

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    100 mg

    $258

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    250 mg

    $561

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    Product Description

    DRB is a nucleoside analog that inhibits several carboxyl-terminal domain (CTD) kinases including casein kinase II (IC50 range of 4-10 µM)1, Cdk7 (IC50 = ~20 µM)2,3, Cdk8 (IC50 = ~20 µM)3, and Cdk9 (IC50 = 3 µM).4 Through inhibition of certain CTD kinases, DRB inhibits an elongation step during RNA polymerase II transcription5,6, which can trigger p53-dependent apoptosis of human colon adenocarcinoma cells without inducing genotoxic stress to healthy cells.7 DRB can also inhibit HIV transcription (IC50 = ~4 µM) by targeting elongation enhanced by the HIV-encoded transactivator Tat.8

    WARNING This product is not for human or veterinary use.

    References & Product Citations
    Product Description References

    1. Zandomeni, R.O. Kinetics of inhibition by 5,6-dichloro-1-β-D-ribofuranosylbenzimidazole on calf thymus casein kinase II. Biochem. J. 262(2), 469-473 (1989).

    2. Yankulov, K., Yamashita, K., Roy, R., et al. The transcriptional elongation inhibitor 5,6-dichloro-1-β-D-ribofuranosylbenzimidazole inhibits transcription factor IIH-associated protein kinase. The Journal of Biological Chemisty 270(41), 23922-23925 (1995).

    3. Rickert, P., Corden, J.L., and Lees, E. Cyclin C/CDK8 and cyclin H/CDK7/p36 are biochemically distinct CTD kinases. Oncogene 18(4), 1093-1102 (1999).

    4. Schang, L.M. Cyclin-dependent kinases as cellular targets for antiviral drugs. J. Antimicrob. Chemother. 50(6), 779-792 (2002).

    5. Zandomeni, R., Zandomeni, M.C., Shugar, D., et al. Casein kinase type II is involved in the inhibition by 5,6-dichloro-1-β-D-ribofuranosylbenzimidazole of specific RNA polymerase II transcription. The Journal of Biological Chemisty 261(7), 3414-3419 (1986).

    6. Yamaguchi, Y., Wada, T., and Handa, H. Interplay between positive and negative elongation factors: drawing a new view of DRB. Genes Cells 3(1), 9-15 (1998).

    7. te Poele, R.H., Okorokov, A.L., and Joel, S.P. RNA synthesis block by 5,6-dichloro-1-β-D-ribofuranosylbenzimidazole (DRB) triggers p53-dependent apoptosis in human colon carcinoma cells. Oncogene 18(42), 5765-5772 (1999).

    8. Marciniak, R.A., and Sharp, P.A. HIV-1 tat protein promotes formation of more-processive elongation complexes. EMBO J. 10(13), 4189-4196 (1991).

    Product Citations

    Price, A.M., Steinbock, R.T., Di, C., et al. Adenovirus prevents dsRNA formation by promoting efficient splicing of viral RNA. Nucleic Acids Res. 50(3), 1201-1220 (2022).