ACX-362E is an orally bioavailable DNA polymerase IIIC (pol IIIC) inhibitor, acts as an antimicrobial agent to treat Gram-positive infections, with a MIC50 of 2 μg/mL for C. difficile. ACX-362E exhibits very potent in vitro and in vivo activities against broad spectrum of C. difficile pathogens.

Physicochemical Properties

Molecular Formula	C18H20CL2N6O2
Molecular Weight	423.2964
Exact Mass	422.102
CAS #	1275582-97-2
PubChem CID	136022209
Appearance	White to off-white solid powder
LogP	1.6
Hydrogen Bond Donor Count	2
Hydrogen Bond Acceptor Count	5
Rotatable Bond Count	6
Heavy Atom Count	28
Complexity	588
Defined Atom Stereocenter Count	0
SMILES	ClC1=C(C=CC(=C1)CNC1=NC2=C(C(N1)=O)N(C=N2)CCN1CCOCC1)Cl
InChi Key	DEGSGBKTODESHH-UHFFFAOYSA-N
InChi Code	InChI=1S/C18H20Cl2N6O2/c19-13-2-1-12(9-14(13)20)10-21-18-23-16-15(17(27)24-18)26(11-22-16)4-3-25-5-7-28-8-6-25/h1-2,9,11H,3-8,10H2,(H2,21,23,24,27)
Chemical Name	2-[(3,4-dichlorophenyl)methylamino]-7-(2-morpholin-4-ylethyl)-1H-purin-6-one
HS Tariff Code	2934.99.9001
Storage	Powder-20°C 3 years 4°C 2 years In solvent -80°C 6 months -20°C 1 month
Shipping Condition	Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Biological Activity

ln Vitro	Ibezapolstat binds to and inhibits DNA pol IIIC of aerobic and low-G+C Gram-positive bacteria[1]. Ibezapolstat exhibits broad-spectrum antibacterial action against C. difficile pathogens, with in vitro MICs ranging from 1-8 μg/mL against 104 C. difficile clinical isolates [1].
ln Vivo	In a hamster model of Clostridium difficile-associated disease (CDAD), ibezapolstat is poorly absorbed and appears harmless (with the potential to achieve high local concentrations at sites of C. difficile infection in the colon) [3]. Ibezabolostat (oral; 50 mg/kg; twice daily; for 3 days) exhibits strong anti-C properties. difficult characteristics in a CDAD model of hamsters [3].
Animal Protocol	Animal/Disease Models: Female Syrian golden hamster (80-90 g), CDAD model [3] Doses: 50 mg/kg Route of Administration: Orally, twice (two times) daily for 3 days Experimental Results: Complete protection of C. difficile-infected animals, sustained A period of up to 5 days.
References	[1]. In vitro activity of the novel antibacterial agent ibezapolstat (ACX-362E) against Clostridioides difficile. J Antimicrob Chemother. 2020 Aug 1;75(8):2149-2155. [2]. Clostridium difficile DNA polymerase IIIC: basis for activity of antibacterial compounds. Curr Enzym Inhib. 2011 Oct; 7(3): 147-153. [3]. A Novel Agent Effective against Clostridium difficile Infection. Antimicrob Agents Chemother. 2012 Mar; 56(3): 1624-1626.
Additional Infomation	Ibezapolstat is under investigation in clinical trial NCT04247542 (ACX-362E [Ibezapolstat] for Oral Treatment of Clostridioides Difficile Infection).

Solubility Data

Solubility (In Vitro)

DMSO : ~62.5 mg/mL (~147.65 mM)

Solubility (In Vivo)

Solubility in Formulation 1: ≥ 2.08 mg/mL (4.91 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 20.8 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL. Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution. Solubility in Formulation 2: ≥ 2.08 mg/mL (4.91 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 20.8 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly. Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution. Solubility in Formulation 3: ≥ 2.08 mg/mL (4.91 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 20.8 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.  (Please use freshly prepared in vivo formulations for optimal results.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	2.3624 mL	11.8120 mL	23.6239 mL
	5 mM	0.4725 mL	2.3624 mL	4.7248 mL
	10 mM	0.2362 mL	1.1812 mL	2.3624 mL

*Note: Please select an appropriate solvent for the preparation of stock solution based on your experiment needs. For most products, DMSO can be used for preparing stock solutions (e.g. 5 mM, 10 mM, or 20 mM concentration); some products with high aqueous solubility may be dissolved in water directly. Solubility information is available at the above Solubility Data section. Once the stock solution is prepared, aliquot it to routine usage volumes and store at -20°C or -80°C. Avoid repeated freeze and thaw cycles.