## Endpoint to Predict
- Endpoint scope: assay
- Measurement type: EC50
- Label type: continuous
- Binary semantics: pchembl
- Assay description: In Vitro GIRK Thallium Flux (2.5 minute) Assay: Human Embryonic Kidney (HEK-293) cell lines co-expressing rat mGlu receptors 2, 3, 4, 6, 7 or 8 and G protein-coupled inwardly-rectifying potassium (GIRK) channels_ENREF_54 were grown in Growth Media containing 45% DMEM, 45% F-12, 10% FBS, 20 mM HEPES, 2 mM L-glutamine, antibiotic/antimycotic, non-essential amino acids, 700 μg/ml G418, and 0.6 μg/ml puromycin at 37° C. in the presence of 5% CO2. All cell culture reagents were purchased from Invitrogen Corp. (Carlsbad, Calif.) unless otherwise noted. Compound activity at the group II (mGlu2 and mGlu3) mGlus was assessed using thallium flux through GIRK channels. Briefly, cells were plated into 384-well, black-walled, clear-bottomed poly-D-lysine-coated plates at a density of 15,000 cells/20 μL/well in DMEM containing 10% dialyzed FBS, 20 mM HEPES, and 100 units/mL penicillin/streptomycin (assay media). Plated cells were incubated overnight at 37° C. in the presence of 5% CO2. The following day, the medium was exchanged from the cells to assay buffer [Hanks' balanced salt solution (Invitrogen) containing 20 mM HEPES, pH 7.3] using an ELX405 microplate washer (BioTek), leaving 20 μL/well, followed by the addition of 20 μL/well FluoZin2-AM (330 nM final concentration) indicator dye (Invitrogen; prepared as a stock in DMSO and mixed in a 1:1 ratio with Pluronic acid F-127) in assay buffer. Cells were incubated for 1 h at room temperature, and the dye exchanged to assay buffer using an ELX405, leaving 20 μL/well. Test compounds were diluted to 2 times their final desired concentration in assay buffer (0.3% DMSO final concentration). Agonists were diluted in thallium buffer [125 mM sodium bicarbonate (added fresh the morning of the experiment), 1 mM magnesium sulfate, 1.8 mM calcium sulfate, 5 mM glucose, 12 mM thallium sulfate, and 10 mM HEPES, pH 7.3] at 5 times the final concentration to be assayed. Cell plates and compound plates were loaded onto a kinetic imaging plate reader (FDSS 6000 or 7000; Hamamatsu Corporation, Bridgewater, N.J.). Appropriate baseline readings were taken (10 images at 1 Hz; excitation, 470±20 nm; emission, 540±30 nm) and test compounds were added in a 20 μL volume and incubated for 2.5 min as indicated before the addition of 10 μL of thallium buffer with or without agonist. After the addition of agonist, data were collected for approximately an additional 2.5 min. Data were analyzed using Excel (Microsoft Corp, Redmond, Wash.). The slope of the fluorescence increase beginning 5 s after thallium/agonist addition and ending 15 s after thallium/agonist addition was calculated, corrected to vehicle and maximal agonist control slope values, and plotted in using either XLfit (ID Business Solutions Ltd) or Prism software (GraphPad Software, San Diego, Calif.) to generate concentration-response curves. Potencies were calculated from fits using a four-point parameter logistic equation. For concentration-response curve experiments, compounds were serially diluted 1:3 into 10 point concentration response curves and were transferred to daughter plates using an Echo acoustic plate reformatter (Labcyte, Sunnyvale, Calif.).
- Assay organism: Rattus norvegicus
- Target name: Metabotropic glutamate receptor 5
- Target type: SINGLE PROTEIN
- Target organism: Rattus norvegicus

## Reference Molecule A
- Canonical SMILES: O=C(O)c1ccc(-c2ccc(-c3nc(-c4ccc(C(F)(F)F)nc4)cc(C(F)(F)F)n3)cc2)cc1
- Properties:
- ChEMBL ID: CHEMBL5823336
- Molecular weight: 489.38
- Heavy atoms: 35
- Hydrogen bond donors: 1
- Hydrogen bond acceptors: 4
- TPSA: 75.97
- LogP: 6.61
- Rotatable bonds: 4
- Ring count: 4
- Aromatic rings: 4
- Formal charge: 0
- Fraction Csp3: 0.08
- QED: 0.33

## Known Reference Result on This Endpoint
- Molecule A clean result: median pChEMBL = 5.67
- This result is provided as context for predicting Molecule B on the same endpoint.

## Reference Molecule A Other ChEMBL Evidence
- type EC50; relation =; value 2130; units nM; pChEMBL 5.67; comment 891482

## Query Molecule B
- Canonical SMILES: Cc1cc(NC(=O)OC(C)(C)C)c(NC(=O)CC(=O)c2cccc(Oc3ccccc3)c2)cc1C(F)(F)F
- Properties:
- ChEMBL ID: CHEMBL5855874
- Molecular weight: 528.53
- Heavy atoms: 38
- Hydrogen bond donors: 2
- Hydrogen bond acceptors: 5
- TPSA: 93.73
- LogP: 7.36
- Rotatable bonds: 7
- Ring count: 3
- Aromatic rings: 3
- Formal charge: 0
- Fraction Csp3: 0.25
- QED: 0.25

## Molecule Similarity
- Weighted Tanimoto: 0.16

Answer: 5.58