## Endpoint to Predict
- Endpoint scope: assay
- Measurement type: IC50
- Label type: continuous
- Binary semantics: pchembl
- Assay description: Phosphodiesterase (PDE) 2A and 10 Assay with Fluorescent Substrate: The inhibition of PDE 2A or 10 enzyme activity was assessed using IMAP-Phosphodiesterase-cAMP fluorescence labeled substrate (Molecular Devices, Order No. R7506), IMAP TR-FRET screening express (Molecular Devices, Order No. R8160, the TR-FRET component will not be used) and PDE 2A or PDE10 protein expressed upon baculovirus infection in SF9 cells. The cells were incubated after infection for 3 days and protein production was confirmed by Western Blot. The cells were collected by centrifugation and the pellet frozen in liquid nitrogen before it was resuspended in PBS containing 1% Triton X-100 and protease inhibitors. After 45 min incubation on ice, the cell debris was removed by centrifugation (13 rpm, 30 min). Since SF 9 cells do not express cAMP hydrolyzing enzymes to a high extent, no further purification of the protein was needed.All reactions were performed in 384 well plates, Perkin Elmer black optiplates and IMAP reaction buffer with 0.1% Tween20 (kit component)Compounds were serial diluted in DMSO. With an intermediate dilution step with reaction buffer DMSO concentration was reduced to achieve 1% DMSO in the assay reaction. Setup of the assay started with 10 μl enzyme (10 ng/well, depending on prep. batch), 5 μl compound, reaction was started by addition of 5 μl labeled cAMP (30 nM, final concentration), immediately mixed for 15 seconds on a Eppendorf mixmate (2000 rpm) followed by an incubation at room temperature for 90 minutes in the dark. Reaction is stopped by adding of 60 μl binding buffer for FP/cAMP (kit component). After at least 90 min of further incubation (room temperature, dark) the assay was measured at 485 nm excitation/525 nm emission in an Envision multilabel reader (PerkinElmer).Each assay plate contained wells with vehicle controls (1% DMSO) for the measurement of non-inhibited reaction (=100% control) and wells without enzyme as 0% controls.The analysis of the data was performed by calculation of the percentage of inhibition in the presence of test compound compared to the vehicle control samples (100% control, no inhibition) and a low control (0% control, no enzyme).
- Assay organism: Homo sapiens
- Target name: cAMP and cAMP-inhibited cGMP 3',5'-cyclic phosphodiesterase 10A
- Target type: SINGLE PROTEIN
- Target organism: Homo sapiens

## Reference Molecule A
- Canonical SMILES: Cc1cnc2c(C(=O)NC3(c4ccc(Cl)cc4F)CCOCC3)c(C)nn2c1
- Properties:
- ChEMBL ID: CHEMBL5896152
- Molecular weight: 402.86
- Heavy atoms: 28
- Hydrogen bond donors: 1
- Hydrogen bond acceptors: 4
- TPSA: 68.52
- LogP: 3.57
- Rotatable bonds: 3
- Ring count: 4
- Aromatic rings: 3
- Formal charge: 0
- Fraction Csp3: 0.35
- QED: 0.73

## Known Reference Result on This Endpoint
- Molecule A clean result: median pChEMBL = 6.26
- This result is provided as context for predicting Molecule B on the same endpoint.

## Reference Molecule A Other ChEMBL Evidence
- type IC50; relation =; value 550; units nM; pChEMBL 6.26; comment 988160

## Query Molecule B
- Canonical SMILES: Cc1nn2cc(C3CC3)cnc2c1C(=O)NC1(c2ccc3ccccc3n2)CCOCC1
- Properties:
- ChEMBL ID: CHEMBL5844688
- Molecular weight: 427.51
- Heavy atoms: 32
- Hydrogen bond donors: 1
- Hydrogen bond acceptors: 5
- TPSA: 81.41
- LogP: 3.9
- Rotatable bonds: 4
- Ring count: 6
- Aromatic rings: 4
- Formal charge: 0
- Fraction Csp3: 0.36
- QED: 0.53

## Molecule Similarity
- Weighted Tanimoto: 0.51

Answer: 5.83