Phenamil methanesulfonate

• CAT Number: R022228
• CAS Number: 1161-94-0
• Molecular Formula: C13H16ClN7O4S
• Molecular Weight: 401.83
• Purity: ≥95%
• Synonyms: 3,5-diamino-6-chloro-N-(N’-phenylcarbamimidoyl)pyrazine-2-carboxamide;methanesulfonic acid
• InChI: InChI=1S/C12H12ClN7O.CH4O3S/c13-8-10(15)19-9(14)7(18-8)11(21)20-12(16)17-6-4-2-1-3-5-6;1-5(2,3)4/h1-5H,(H4,14,15,19)(H3,16,17,20,21);1H3,(H,2,3,4)
• InChIKey: MHPIZTURFVSLTJ-UHFFFAOYSA-N
• SMILES: CS(=O)(=O)O.C1=CC=C(C=C1)N=C(N)NC(=O)C2=C(N=C(C(=N2)Cl)N)N

Phenamil methanesulfonate, an analog of Amiloride (HY-B0285), is a more potent and less reversible epithelial sodium channel (ENaC) blocker with an IC50 of 400 nM[2]. Phenamil methanesulfonate is also a competive inhibitor of TRPP3 and inhibits TRPP3-mediated Ca2+ transport with an IC50 of 140 nM in a Ca2+ uptake assay[1]. Phenamil methanesulfonate is an intriguing small molecule to promote bone repair by strongly activating BMP signaling pathway[4]. Phenamil methanesulfonate is used for the research of cystic fibrosis lung disease[5].
TRPP3, a member of the transient receptor potential (TRP) superfamily of cation channels, is a Ca2+-activated channel permeable to Ca2+, Na+, and K+. TRPP3 is implicated in regulation of pH-sensitive action potential in spinal cord neurons.
Phenamil methanesulfonate (1 μM) decreases 45Ca2+ uptake in a radiotracer uptake assay. It inhibits TRPP3-mediated Ca2+ transport with an IC50 value of 0.28 μM in oocytes expressing TRPP3 or H2O-injected oocytes[1].
Phenamil methanesulfonate is a more potent ENaC blocker than Amiloride, it inhibits the epithelial sodium channel (ENaC) with an IC50 of 400 nM (Amiloride=776 nM)[2].Phenamil methanesulfonate inhibits basal short-circuit currents with IC50 values of 75 and 116 nM, respectively in both human and ovine bronchial epithelia cells[3].Phenamil methanesulfonate (0-20 μM; 14 days) elevates adipogenic gene expression, PPARγ, Fabp4, and lipoprotein lipase expression in a concentration-dependent manner ,and regulates adipogenesis in C3H10T1/2 cells[4].Phenamil methanesulfonate (0-20 μM; 7 or 14 days) modulates MC3T3-E1 osteoblastic differentiation, it increases Alkaline phosphatase (ALP) activity in MC3T3-E1 cells in a concentration-dependent manner[4].
Phenamil methanesulfonate (subcutaneous injection; 15 or 30 mg/kg; 21 days; infusion rate of 1 ml/h) reduces chronic-hypoxia-induced pulmonary artery hypertension (PAH). Additionally, the mRNA level of SMA, SM22, Id3, and Trb3 from the lung sample are also decreased by Phenamil under hypoxia or normoxia in rats. However, phenamil has little effect on pulmonary vasculature under physiological conditions[5].

Reference

[1]. Xiao-Qing Dai , et al. Inhibition of TRPP3 channel by amiloride and analogs. Mol Pharmacol. . 2007 Dec;72(6):1576-85.
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[2]. Andrew J Hirsh, et al.Design, synthesis, and structure-activity relationships of novel 2-substituted pyrazinoylguanidine epithelial sodium channel blockers: drugs for cystic fibrosis and chronic bronchitis. J Med Chem. 2006 Jul 13;49(14):4098-115.
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[3]. Andrew J Hirsh, et al.Evaluation of second generation amiloride analogs as therapy for cystic fibrosis lung disease.J Pharmacol Exp Ther. 2004 Dec;311(3):929-38.
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[4]. Mun Chun Chan, et al. The amiloride derivative phenamil attenuates pulmonary vascular remodeling by activating NFAT and the bone morphogenetic protein signaling pathway. Mol Cell Biol
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