MELK-8a hydrochloride

• CAT Number: I031907
• CAS Number: 2096992-20-8
• Molecular Formula: C25H33ClN6O
• Molecular Weight: 469.02
• Purity: ≥95%
• Synonyms: 1-methyl-4-[4-[4-[3-(piperidin-4-ylmethoxy)pyridin-4-yl]pyrazol-1-yl]phenyl]piperazine;hydrochloride
• InChI: InChI=1S/C25H32N6O.ClH/c1-29-12-14-30(15-13-29)22-2-4-23(5-3-22)31-18-21(16-28-31)24-8-11-27-17-25(24)32-19-20-6-9-26-10-7-20;/h2-5,8,11,16-18,20,26H,6-7,9-10,12-15,19H2,1H3;1H
• InChIKey: AFGMSRRNYDSRPT-UHFFFAOYSA-N
• SMILES: CN1CCN(CC1)C2=CC=C(C=C2)N3C=C(C=N3)C4=C(C=NC=C4)OCC5CCNCC5.Cl

MELK-8a hydrochloride is a novel maternal embryonic leucine zipper kinase (MELK) inhibitor with an IC50 of 2 nM.
MELK-8a remains very potent (IC50=140 nM) when the ATP concentration in the biochemical assay is shifted from 20 μM to 2 mM. Its potency is well tracked between full-length MELK versus catalytic domain construct (5 nM versus 2 nM). It only inhibits seven off-target kinases in addition to MELK with >85% inhibition of binding at 1 μM demonstrating great selectivity. The compound is at least 90-fold more selective in targeting MELK in all cases. MELK-8a is fairly soluble (0.22 g/L at pH 6.8) and shows a good permeability in the Caco-2 assay. MELK-8a inhibits the growth of MDA-MB-468 cells and MCF-7 cells with an IC50 of approximately 0.06 and 1.2 μM, respectively[1].
Subcutaneous administration of MELK-8a at 30 mg/kg in C57BL/6 mice results in good plasma exposure. The compound adsorption into the systemic circulation is rapid (Tmax=0.4 h) and peak plasma concentration reaches 6.6 μM. An ascending dose PK study in female athymic nude mice shows that the rate of compound release is maximal at 120 mg/kg and all clearance mechanisms can be saturated at 240 mg/kg. However, when administered orally at 10 mg/kg in C57BL/6 male mice, it shows very poor PK (3.6% oral bioavailability) consistent with very high in vivo clearance[1].

Reference

[1]. Touré BB, et al. Toward the Validation of Maternal Embryonic Leucine Zipper Kinase: Discovery, Optimization of Highly Potent and Selective Inhibitors, and Preliminary Biology Insight. J Med Chem. 2016 May 26;59(10):4711-23.
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