A dye and derivative of glutamate with diverse biological activities
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Chicago Sky Blue 6B

Item No. 31542

Product Insert (PDF)Safety Data Sheet (SDS) (PDF)
Technical Information
Formal Name
6,6′-[(3,3′-dimethoxy[1,1′-biphenyl]-4,4′-diyl)bis(2,1-diazenediyl)]bis[4-amino-5-hydroxy-1,3-naphthalenedisulfonic acid, tetrasodium salt
CAS Number
2610-05-1
Synonyms
  • Chicago Skye Blue 6B
  • C.I. 24410
  • CSB6B
  • NCI 9617
  • Pontamine Sky Blue
Molecular Formula
C34H24N6O16S4 • 4Na
Formula Weight
992.8
Purity
≥90%
Formulation (Request formulation change)
A crystalline solid
Solubility(Learn about Variance in Solubility)
PBS (pH 7.2): 10 mg/ml
λmax
319, 608 nm
SMILES
COC1=CC(C2=CC=C(C(OC)=C2)/N=N/C(C=CC3=C(S([O-])(=O)=O)C=C4S([O-])(=O)=O)=C(O)C3=C4N)=CC=C1/N=N/C(C=CC5=C(S([O-])(=O)=O)C=C6S([O-])(=O)=O)=C(C5=C6N)O.[Na+].[Na+].[Na+].[Na+]
InChi Code
InChI=1S/C34H28N6O16S4.4Na/c1-55-23-11-15(3-7-19(23)37-39-21-9-5-17-25(57(43,44)45)13-27(59(49,50)51)31(35)29(17)33(21)41)16-4-8-20(24(12-16)56-2)38-40-22-10-6-18-26(58(46,47)48)14-28(60(52,53)54)32(36)30(18)34(22)42;;;;/h3-14,41-42H,35-36H2,1-2H3,(H,43,44,45)(H,46,47,48)(H,49,50,51)(H,52,53,54);;;;/q;4*+1/p-4/b39-37+,40-38+;;;;
InChi Key
BPHHNXJPFPEJOF-GPTZEZBUSA-J
Shipping & Storage Information
Storage
-20°C
Shipping
Room temperature in continental US; may vary elsewhere
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    Product Description

    CSB6B is a dye and derivative of glutamate with diverse biological activities.1,2,3,4,5 It is a competitive inhibitor of vesicular glutamate transporters (vGLUTs), inhibiting glutamate uptake by rat brain synaptic vesicles (Ki = 0.19 µM) but not by synaptosomes when used at a concentration of 0.1 mM.1 CSB6B is also an inhibitor of calcium/calmodulin-dependent protein kinase phosphatase (CaMKP) and its nuclear isoform CaMKP-N (IC50s = 4.1 and 1 µM, respectively).2 It is selective for CaMKP and CaMKP-N over protein phosphatase 2C (PP2C) and calcineurin, which it inhibits by less than 10 and 20%, respectively, at 10 µM. CSB6B inhibits sodium/taurocholate cotransporting polypeptide (NTCP; IC50 = 7.1 µM) and reduces hepatitis B virus (HBV) and hepatitis delta virus (HDV) infection in HepaRG cells when used at a concentration of 17 µM.3 Intracerebroventricular administration of CSB6B (0.5 µg) inhibits inflammatory pain in mice, reducing writhing induced by acetic acid and nociceptive behavior during the second phase of the formalin test without affecting locomotor activity.4 It also reduces thermal hyperalgesia in the complete Freund’s adjuvant test but not thermal pain in the hot plate test. CSB6B has also been used as a counterstain to reduce background autofluorescence in immunohistochemical preparations.5

    WARNING This product is not for human or veterinary use.

    References & Product Citations
    Product Description References

    1. Roseth, S., Fykse, E.M., and Fonnum, F. Uptake of L-glutamate into rat brain synaptic vesicles: Effect of inhibitors that bind specifically to the glutamate transporter. J. Neurochem. 65(1), 96-103 (1995).

    2. Sueyoshi, N., Takao, T., Nimura, T., et al. Inhibitors of the Ca2+/calmodulin-dependent protein kinase phosphatase family (CaMKP and CaMKP-N). Biochem. Biophys. Res. Commun. 363(3), 715-721 (2007).

    3. Donkers, J.M., Zehnder, B., van Westen, G.J.P., et al. Reduced hepatitis B and D viral entry using clinically applied drugs as novel inhibitors of the bile acid transporter NTCP. Sci. Rep. 7(1), 15307 (2017).

    4. Yu, G., Yi, S., Wang, M., et al. The antinociceptive effects of intracerebroventricular administration of Chicago sky blue 6B, a vesicular glutamate transporter inhibitor. Behav. Pharmacol. 24(8), 653-658 (2013).

    5. Cowen, T., Haven, A.J., and Burnstock, G. Pontamine sky blue: A counterstain for background autofluorescence in fluorescence and immunofluorescence histochemistry. Histochemistry 82(3), 205-208 (1985).