## Endpoint to Predict
- Endpoint scope: assay
- Measurement type: IC50
- Label type: continuous
- Binary semantics: pchembl
- Assay description: PI3K-delta Scintillation Proximity Assay: [γ-33P]ATP (10 mCi/mL) and Wheat Germ Agglutinin (WGA) YSi SPA Scintillation Beads was purchased from Perkin-Elmer (Waltham, Mass.). Lipid kinase substrate, D-myo-Phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2)D (+)-sn-1,2-di-O-octanoylglyceryl, 3-O-phospho linked (PIP2), CAS 204858-53-7, was purchased from Echelon Biosciences (Salt Lake City, Utah). PI3Kδ (p110δ/p85α) Recombinant Human Protein was purchased from Eurofins (St Charles, Mo.). ATP, MgCl2, DTT, EDTA, MOPS and CHAPS were purchased from Sigma-Aldrich (St. Louis, Mo.).The kinase reaction was conducted in polystyrene 384-well Greiner Bio-one white plate from Thermo Fisher Scientific in a final volume of 25 μL. Inhibitors were first diluted serially in DMSO and added to the plate wells before the addition of other reaction components. The final concentration of DMSO in the assay was 2%. The PI3Kδ assay was carried out at room temperature in 20 mM MOPS, pH 6.7, 10 mM MgCl2, 5 mM DTT and CHAPS 0.03%. Reactions were initiated by the addition of ATP, the final reaction mixture consisted of 20 μM PIP2, 2 μM ATP, 0.5 μCi [γ-33P] ATP, 3.4 nM PI3Kδ. Reactions were incubated for 120 min and terminated by the addition of 40 μL SPA beads suspended in quench buffer: 163 mM potassium phosphate pH 7.8, 20% glycerol, 25 mM EDTA. The final concentration of SPA beads is 1 mg/mL. After the plate sealing, plates were shaken overnight at room temperature and centrifuged at 1500 rpm for 10 min, the radioactivity of the product was determined by scintillation counting on Topcount (Perkin-Elmer). IC50 determination was performed by fitting the curve of percent of the solvent control activity versus the log of the inhibitor concentration using the GraphPad Prism 6 software.
- Assay organism: Homo sapiens
- Target name: Phosphatidylinositol 4,5-bisphosphate 3-kinase catalytic subunit delta isoform
- Target type: SINGLE PROTEIN
- Target organism: Homo sapiens

## Reference Molecule A
- Canonical SMILES: CCOc1c([C@@H](C)n2nc(C)c3c(N)ncnc32)cc(Cl)c(F)c1[C@H]1CNC(=O)C1
- Properties:
- ChEMBL ID: CHEMBL5862784
- Molecular weight: 432.89
- Heavy atoms: 30
- Hydrogen bond donors: 2
- Hydrogen bond acceptors: 6
- TPSA: 107.95
- LogP: 3.12
- Rotatable bonds: 5
- Ring count: 4
- Aromatic rings: 3
- Formal charge: 0
- Fraction Csp3: 0.4
- QED: 0.64

## Known Reference Result on This Endpoint
- Molecule A clean result: median pChEMBL = 7.5
- This result is provided as context for predicting Molecule B on the same endpoint.

## Reference Molecule A Other ChEMBL Evidence
- type IC50; relation =; value 32; units nM; pChEMBL 7.5; comment 514705

## Query Molecule B
- Canonical SMILES: CCOc1c([C@@H](C)n2nc(C)c3c(N)ncnc32)cc(Cl)c(F)c1[C@@H]1CNC(=O)C1
- Properties:
- ChEMBL ID: CHEMBL6035047
- Molecular weight: 432.89
- Heavy atoms: 30
- Hydrogen bond donors: 2
- Hydrogen bond acceptors: 6
- TPSA: 107.95
- LogP: 3.12
- Rotatable bonds: 5
- Ring count: 4
- Aromatic rings: 3
- Formal charge: 0
- Fraction Csp3: 0.4
- QED: 0.64

## Molecule Similarity
- Weighted Tanimoto: 1

Answer: 7.5