STO-609 acetate

    WARNING: This product is for research use only, not for human or veterinary use.

MedKoo CAT#: 555213

CAS#: 1173022-21-3 (acetate)

Description: STO-609 is a cell-permeable inhibitor of calcium/calmodulin-dependent kinase kinases (CaMKK) isoforms CaMKKα and CaMKKβ (Ki = 80 and 15 ng/ml, respectively). STO-609 is a selective and cell-permeable inhibitor of CaM-KK and that it may be a useful tool for evaluating the physiological significance of the CaM-KK-mediated pathway in vivo as well as in vitro.

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STO-609 acetate is not in stock, may be available through custom synthesis. For cost-effective reason, minimum 1 gram order is requested. The product will be characterized by NMR, HPLC and MS analysis. Purity (HPLC) is usually >98%. CoA, QC data, MSDS will be provided when product is successfully made. The estimated lead time is 2-3 months. Please send email to to inquire quote.

Chemical Structure


Theoretical Analysis

MedKoo Cat#: 555213
Name: STO-609 acetate
CAS#: 1173022-21-3 (acetate)
Chemical Formula: C21H14N2O5
Exact Mass:
Molecular Weight: 374.352
Elemental Analysis: C, 67.38; H, 3.77; N, 7.48; O, 21.37

Related CAS #: 52029-86-4 (free base)   1173022-21-3 (acetate)    

Synonym: STO-609 acetate; STO 609; STO609;

IUPAC/Chemical Name: 7-oxo-7H-benzimidazo[2,1-a]benz[de]isoquinoline-3-carboxylic acid, monoacetate

InChi Key: InChI=1S/C19H10N2O3.C2H4O2/c22-18-13-5-3-4-10-11(19(23)24)8-9-12(16(10)13)17-20-14-6-1-2-7-15(14)21(17)18;1-2(3)4/h1-9H,(H,23,24);1H3,(H,3,4)

InChi Code: InChI=1S/C19H10N2O3.C2H4O2/c22-18-13-5-3-4-10-11(19(23)24)8-9-12(16(10)13)17-20-14-6-1-2-7-15(14)21(17)18;1-2(3)4/h1-9H,(H,23,24);1H3,(H,3,4)

SMILES Code: O=C(C1=C2C3=C(C4=NC5=CC=CC=C5N4C(C3=CC=C2)=O)C=C1)O.CC(O)=O

Technical Data

Solid powder

>98% (or refer to the Certificate of Analysis)

Shipping Condition:
Shipped under ambient temperature as non-hazardous chemical. This product is stable enough for a few weeks during ordinary shipping and time spent in Customs.

Storage Condition:
Dry, dark and at 0 - 4 C for short term (days to weeks) or -20 C for long term (months to years).

Soluble in DMSO

Shelf Life:
>2 years if stored properly

Drug Formulation:
This drug may be formulated in DMSO

Stock Solution Storage:
0 - 4 C for short term (days to weeks), or -20 C for long term (months).

Harmonized System Code:


1: York B, Li F, Lin F, Marcelo KL, Mao J, Dean A, Gonzales N, Gooden D, Maity S, Coarfa C, Putluri N, Means AR. Pharmacological inhibition of CaMKK2 with the selective antagonist STO-609 regresses NAFLD. Sci Rep. 2017 Sep 18;7(1):11793. doi: 10.1038/s41598-017-12139-3. PubMed PMID: 28924233; PubMed Central PMCID: PMC5603587.

2: Gerner L, Munack S, Temmerman K, Lawrence-Dörner AM, Besir H, Wilmanns M, Jensen JK, Thiede B, Mills IG, Morth JP. Using the fluorescent properties of STO-609 as a tool to assist structure-function analyses of recombinant CaMKK2. Biochem Biophys Res Commun. 2016 Jul 22;476(2):102-7. doi: 10.1016/j.bbrc.2016.05.045. Epub 2016 May 11. PubMed PMID: 27178209.

3: Ma Z, Wen D, Wang X, Yang L, Liu T, Liu J, Zhu J, Fang X. Growth inhibition of human gastric adenocarcinoma cells in vitro by STO-609 is independent of calcium/calmodulin-dependent protein kinase kinase-beta and adenosine monophosphate-activated protein kinase. Am J Transl Res. 2016 Feb 15;8(2):1164-71. eCollection 2016. PubMed PMID: 27158402; PubMed Central PMCID: PMC4846959.

4: Fujiwara Y, Hiraoka Y, Fujimoto T, Kanayama N, Magari M, Tokumitsu H. Analysis of Distinct Roles of CaMKK Isoforms Using STO-609-Resistant Mutants in Living Cells. Biochemistry. 2015 Jun 30;54(25):3969-77. doi: 10.1021/acs.biochem.5b00149. Epub 2015 Jun 18. PubMed PMID: 26050738.

5: Kukimoto-Niino M, Yoshikawa S, Takagi T, Ohsawa N, Tomabechi Y, Terada T, Shirouzu M, Suzuki A, Lee S, Yamauchi T, Okada-Iwabu M, Iwabu M, Kadowaki T, Minokoshi Y, Yokoyama S. Crystal structure of the Ca²⁺/calmodulin-dependent protein kinase kinase in complex with the inhibitor STO-609. J Biol Chem. 2011 Jun 24;286(25):22570-9. doi: 10.1074/jbc.M111.251710. Epub 2011 Apr 19. PubMed PMID: 21504895; PubMed Central PMCID: PMC3121401.

6: Monteiro P, Gilot D, Langouet S, Fardel O. Activation of the aryl hydrocarbon receptor by the calcium/calmodulin-dependent protein kinase kinase inhibitor 7-oxo-7H-benzimidazo[2,1-a]benz[de]isoquinoline-3-carboxylic acid (STO-609). Drug Metab Dispos. 2008 Dec;36(12):2556-63. doi: 10.1124/dmd.108.023333. Epub 2008 Aug 28. PubMed PMID: 18755850.

7: Tokumitsu H, Inuzuka H, Ishikawa Y, Kobayashi R. A single amino acid difference between alpha and beta Ca2+/calmodulin-dependent protein kinase kinase dictates sensitivity to the specific inhibitor, STO-609. J Biol Chem. 2003 Mar 28;278(13):10908-13. Epub 2003 Jan 22. PubMed PMID: 12540834.

8: Tokumitsu H, Inuzuka H, Ishikawa Y, Ikeda M, Saji I, Kobayashi R. STO-609, a specific inhibitor of the Ca(2+)/calmodulin-dependent protein kinase kinase. J Biol Chem. 2002 May 3;277(18):15813-8. Epub 2002 Feb 26. Erratum in: J Biol Chem. 2003 Feb 7;278(6):4368. PubMed PMID: 11867640.