## Endpoint to Predict
- Endpoint scope: assay
- Measurement type: IC50
- Label type: continuous
- Binary semantics: pchembl
- Assay description: NR2B Antagonist Activity: HEK293 cell lines stably expressing cloned human NR1/NR2B and NR1/NR2A, respectively, were established according to standard previously described methods (Hansen et al., Comb. Chem High Throughput Screen. 11:304, 2008). Activation of the NR2A or NR2B subtype of NMDA receptor with glutamate as an agonist and glycine co-agonist on these cells results in calcium influx, which can be monitored with fluorescent indicator Fluo-4. A cell based assay has been implemented to evaluate the effect of a compound on NR2A and NR2B receptors by measuring the fluorescent changes (Hansen et al., Comb. Chem High Throughput Screen. 11:304, 2008).HEK293 cells stably expressing NR2A or NR2B receptors were cultured at 37° C. in a humidified CO2 incubator in DMEM supplemented with 10% fetal bovine serum (FBS) (Hyclone), 10 μM MK801 (Sigma-Aldrich) and 50 μM AP-5 (Tocris). For experiments, the cells were seeded onto poly-D-lysine-coated 96-well black plates with clear bottom (Corning) at a density of 50,000 cells/well. After overnight culture, the growth medium was removed from the wells and the cells were incubated at 37° C. for 60 min in Hanks buffer containing 4 μM fluo-4-AM (Invitrogen) and 0.1% bovine serum albumin (BSA). After dye-loading, the cells were washed three times with Hanks buffer and incubated for 10 min at room temperature with various concentrations of test compounds prepared in Hanks buffer with 0.1% BSA. The cell plates were placed onto FDSS μCell fluorescence reader (Hamamatsu). After 20 sec reading of background fluorescence, agonist glutamate at final 100 μM and co-agonist glycine at final 50 μM were added to the cells to activate the receptor, and the resulting fluorescence changes were recorded and quantified. Based on the changes in fluorescence intensity, the pharmacological effect of test compounds were analyzed and the IC50 values derived from a non-linear least squares fitting of the concentration-dependent response to a standard logistic equation using Prism (Graphpad, Inc): Amplitude=Max Amplitude/(1+(IC50/[antagonist])n).
- Assay organism: Homo sapiens
- Target name: Glutamate receptor ionotropic, NMDA 2B
- Target type: SINGLE PROTEIN
- Target organism: Homo sapiens

## Reference Molecule A
- Canonical SMILES: FC(F)Oc1ccc(C(F)(F)CN2CCC(Nc3ncnc4[nH]ncc34)CC2)nc1
- Properties:
- ChEMBL ID: CHEMBL5950834
- Molecular weight: 425.39
- Heavy atoms: 30
- Hydrogen bond donors: 2
- Hydrogen bond acceptors: 7
- TPSA: 91.85
- LogP: 3.02
- Rotatable bonds: 7
- Ring count: 4
- Aromatic rings: 3
- Formal charge: 0
- Fraction Csp3: 0.44
- QED: 0.56

## Known Reference Result on This Endpoint
- Molecule A clean result: median pChEMBL = 7.64
- This result is provided as context for predicting Molecule B on the same endpoint.

## Reference Molecule A Other ChEMBL Evidence
- type IC50; relation =; value 23; units nM; pChEMBL 7.64; comment 535339

## Query Molecule B
- Canonical SMILES: Fc1cc(Cl)cnc1C(F)(F)CN1CCC(Nc2ncnc3[nH]ncc23)CC1
- Properties:
- ChEMBL ID: CHEMBL5896826
- Molecular weight: 411.82
- Heavy atoms: 28
- Hydrogen bond donors: 2
- Hydrogen bond acceptors: 6
- TPSA: 82.62
- LogP: 3.21
- Rotatable bonds: 5
- Ring count: 4
- Aromatic rings: 3
- Formal charge: 0
- Fraction Csp3: 0.41
- QED: 0.67

## Molecule Similarity
- Weighted Tanimoto: 0.59

Answer: 7.52