## Endpoint to Predict
- Endpoint scope: assay
- Measurement type: IC50
- Label type: continuous
- Binary semantics: pchembl
- Assay description: Binding Assay: Preparation of membranes containing recombinantly expressed sodium channels: Frozen recombinant cell pellets were thawed on ice and diluted to 4 times the cell pellet weight with ice cold 50 mM Tris HCl, pH 7.4 buffer. The cell suspensions were homogenized on ice using a motorized glass dounce homogeniser. Homogenates were further diluted 8.4 times with ice cold 50 mM Tris HCl, pH 7.4 buffer and then centrifuged at 200×g at 4° C. for 15 min. The supernatants were collected and centrifuged at 10000×g at 4° C. for 50 min. The pellets were then re-suspended in 100 mM NaCl, 20 mM Tris HCl, pH 7.4 buffer containing 1% v/v protease inhibitors (Calbiochem) and re-homogenized on ice. The homogenized membranes were then processed through a syringe equipped with a 26 gauge needle. Protein concentrations were determined by Bradford Assay and the membranes were stored at −80° C.Radioligand Binding Studies: Saturation experiments. A representative compound of formula (I) was tritiated. Three tritiums were incorporated in place of methyl hydrogens to generate [3H]compound. Binding of this radioligand was performed in 5 mL borosilicate glass test tubes at room temperature. Binding was initiated by adding membranes to increasing concentrations of [3H]compound in 100 mM NaCl, 20 mM Tris HCl, pH 7.4 buffer containing 0.01% w/v bovine serum albumin (BSA) for 18 h. Non-specific binding was determined in the presence of 1 μM unlabelled compound. After 18 h, the reactants were filtered through GF/C glass fiber filters presoaked in 0.5% w/v polyethylene imine. Filters were washed with 15 mL ice cold 100 mM NaCl, 20 mM Tris HCl, pH 7.4 buffer containing 0.25% BSA to separate bound from free ligand. [3H]compound bound to filters was quantified by liquid scintillation counting.Competitive binding experiments. Binding reactions were performed in 96-well polypropylene plates at room temperature for 18 h. In 360 μL, membranes were incubated with 100 pM [3H]compound and increasing concentrations of Test Compound. Non-specific binding was defined in the presence of 1 μM unlabelled compound. Reactions were transferred and filtered through 96-well glass fiber/C filter plates presoaked with 0.5% polyethylene imine. The filtered reactions were washed 5 times with 200 μL ice cold buffer containing 0.25% BSA. Bound radioactivity was determined by liquid scintillation counting.
- Target name: Sodium channel protein type 9 subunit alpha
- Target type: SINGLE PROTEIN
- Target organism: Homo sapiens

## Reference Molecule A
- Canonical SMILES: NS(=O)(=O)NC(=O)c1cc(Cl)c(Oc2cnc(Cl)c(Cl)c2)cc1F
- Properties:
- ChEMBL ID: CHEMBL5864283
- Molecular weight: 414.63
- Heavy atoms: 24
- Hydrogen bond donors: 2
- Hydrogen bond acceptors: 5
- TPSA: 111.38
- LogP: 2.91
- Rotatable bonds: 4
- Ring count: 2
- Aromatic rings: 2
- Formal charge: 0
- Fraction Csp3: 0
- QED: 0.75

## Known Reference Result on This Endpoint
- Molecule A clean result: median pChEMBL = 5.33
- This result is provided as context for predicting Molecule B on the same endpoint.

## Reference Molecule A Other ChEMBL Evidence
- type IC50; relation =; value 4678; units nM; pChEMBL 5.33; comment 523982

## Query Molecule B
- Canonical SMILES: O=C(NS(=O)(=O)NC1CCC1)c1cc(Cl)c(Oc2ccc(OC(F)(F)F)c(Cl)c2)cc1F
- Properties:
- ChEMBL ID: CHEMBL6017612
- Molecular weight: 517.28
- Heavy atoms: 32
- Hydrogen bond donors: 2
- Hydrogen bond acceptors: 5
- TPSA: 93.73
- LogP: 4.94
- Rotatable bonds: 7
- Ring count: 3
- Aromatic rings: 2
- Formal charge: 0
- Fraction Csp3: 0.28
- QED: 0.51

## Molecule Similarity
- Weighted Tanimoto: 0.47

Answer: 6.97