## Endpoint to Predict
- Endpoint scope: assay
- Measurement type: IC50
- Label type: continuous
- Binary semantics: pchembl
- Assay description: Thallium Flux Assay: The ROMK channel functional thallium flux assay is performed in 384 wells, using the FLIPR-Tetra instrument. HEK-hKir1.1 cells are seeded in Poly-D-Lysine microplates and kept in a 37° C.-10% CO2 incubator overnight. On the day of the experiment, the growth media is replaced with the FluxOR reagent loading buffer and incubated, protected from light, at ambient temperature (23-25° C.) for 90 min. The loading buffer is replaced with assay buffer test compound followed by 30 min incubation at ambient temperature, where the Thallium/Potassium stimulant is added to the microplate. Step Protocol 1. Seed HEK-hKir1.1 cells (50 ul at 20,000 cells/well) in 384-well PDL coated Microplates 2. Allow cells to adhere overnight in humidified 37° C./10% CO2 incubator 3. Completely remove cell growth media from microplate and replace with 25 ul loading buffer 4. Incubate Microplate at room temperature, protected form light, for 90 min 5. Remove loading buffer and replace with 25 ul 1x Assay BufferÂ±test compound.Â 6. Incubate microplate at room temperature, protected form light, for 30 min 7. At FLIPR-Tetra 384: Add stimulant (Thallium/Potassium) solution to microplate and monitor fluorescence. Excitation=400 nm, Emission=460 & 580 nm. Collect data for 10 min.Â Data Calculation: The fluorescence intensity of wells containing 3 uM of a standard control ROMK inhibitor of the present invention is used to define the ROMK-sensitive component of thallium flux. Fluorescence in the presence of test compounds is normalized to control values to provide % fluorescence change. IC50 values represent the concentration of compound that inhibits 50% of the ROMK thallium flux signal.
- Assay organism: Homo sapiens
- Target name: ATP-sensitive inward rectifier potassium channel 1
- Target type: SINGLE PROTEIN
- Target organism: Homo sapiens

## Reference Molecule A
- Canonical SMILES: Cc1c([C@@H](O)CN2CC3CCN(C[C@H](O)c4ccc5c(c4C)COC5=O)C3C2)ccc2c1COC2=O
- Properties:
- ChEMBL ID: CHEMBL3912073
- Molecule type: Small molecule
- Molecular weight: 492.57
- Heavy atoms: 36
- Hydrogen bond donors: 2
- Hydrogen bond acceptors: 8
- TPSA: 99.54
- LogP: 2.42
- Rotatable bonds: 6
- Ring count: 6
- Aromatic rings: 2
- Formal charge: 0
- Fraction Csp3: 0.5
- QED: 0.59

## Known Reference Result on This Endpoint
- Molecule A clean result: median pChEMBL = 7.21
- This result is provided as context for predicting Molecule B on the same endpoint.

## Reference Molecule A Other ChEMBL Evidence
- type IC50; relation =; value 62; units nM; pChEMBL 7.21; comment 442027

## Query Molecule B
- Canonical SMILES: Cc1c([C@@H](O)CN2CCC3(CC2)CCN(C[C@H](O)c2ccc4c(c2C)COC4=O)C3)ccc2c1COC2=O
- Properties:
- ChEMBL ID: CHEMBL3921716
- Molecule type: Small molecule
- Molecular weight: 520.63
- Heavy atoms: 38
- Hydrogen bond donors: 2
- Hydrogen bond acceptors: 8
- TPSA: 99.54
- LogP: 3.2
- Rotatable bonds: 6
- Ring count: 6
- Aromatic rings: 2
- Formal charge: 0
- Fraction Csp3: 0.53
- QED: 0.56

## Molecule Similarity
- Weighted Tanimoto: 0.61

Answer: 5.92