## Endpoint to Predict
- Endpoint scope: assay
- Measurement type: IC50
- Label type: continuous
- Binary semantics: pchembl
- Assay description: Inhibitory Activity Assay: 1. Take 10 mM stock solution of the test compound, in 96-well compound plate, DMSO was used to dilute the compound to an initial concentration of 100×, then this concentration was used as the first concentration, 3-fold diluted to make 10 serial concentrations; 1 μL each serial dilution was then added to 19 μL 1×reaction buffer to prepare 5×compound for use; 2 μL 5×compound was transferred from 96-well plate to 384-well plate; compound-free control well was added with 2 μL the following liquid: 1×reaction buffer with the addition of 1 μL DMSO; 2 μL 250 mM EDTA was added to the Min control well.2.1× reaction buffer was used to formulate the kinase, substrate and ATP into a 2.5×enzyme/substrate mixture and 2.5×ATP solution respectively. In the experiment, the final concentration of CDK4/CycD3 kinase is 0.76 ng/μL, the final concentration of ATP is 80 μM; the final concentration of CDK6/CycD3 kinase is 0.5 ng/μL, the final concentration of ATP is 50 μM; the final concentration of CDK2/CycA2 kinase is 0.86 ng/μL, the final concentration of ATP is 15 μM; the final concentration of CDK2/CycE1 kinase is 1.02 ng/μL, the final concentration of ATP is 20 μM; 2.5×enzyme/substrate mixture was added to a 384-well plate, incubated at room temperature for 5 minutes; then added with 2.5×ATP solution, reacted at room temperature for 30 minutes.3. LANCE® Detection Buffer was used, 1× to prepare 2×LANCE® Ultra Europium-anti-phospho-eIF4E-binding protein 1 (Thr37/46) for use. After the enzymatic reaction was continued for 30 minutes, 10 mM EDTA was added to 384-well plate and the mixture was reacted at room temperature for 5 minutes. Then LANCE® Ultra Europium-anti-phospho-eIF4E-binding protein 1 (Thr37/46) was added, reacted at room temperature for 1 hour.4. The 384-well plate was placed in HERAEUS Multifuge X1R centrifuge, centrifuged at 2000 rpm for 2 minutes; data were measured on EnVision, 337 nM wavelength laser was used as the excitation light, test at RFU665 nM and RFU615 nM, and RFU665 nM/RFU615 nM×10000 was used as the final data for analysis.
- Assay organism: Homo sapiens
- Target name: Cyclin-dependent kinase 5
- Target type: SINGLE PROTEIN
- Target organism: Homo sapiens

## Reference Molecule A
- Canonical SMILES: Cc1nc2c(F)cc(-c3nc(Nc4ccc5c(n4)CCN(CCN(C)C)C5)ncc3F)cc2n1C(C)C1CC1
- Properties:
- ChEMBL ID: CHEMBL4550287
- Molecule type: Unknown
- Molecular weight: 532.64
- Heavy atoms: 39
- Hydrogen bond donors: 1
- Hydrogen bond acceptors: 7
- TPSA: 75
- LogP: 5.11
- Rotatable bonds: 8
- Ring count: 6
- Aromatic rings: 4
- Formal charge: 0
- Fraction Csp3: 0.45
- QED: 0.34

## Known Reference Result on This Endpoint
- Molecule A clean result: median pChEMBL = 7.82
- This result is provided as context for predicting Molecule B on the same endpoint.

## Reference Molecule A Other ChEMBL Evidence
- type IC50; relation =; value 15.3; units nM; pChEMBL 7.82; comment 1028809

## Query Molecule B
- Canonical SMILES: CCN1CCN(Cc2ccc(Nc3ncc(F)c(-c4cc(F)c5nc(C)n(C(C)C)c5c4)n3)nc2)CC1
- Properties:
- ChEMBL ID: CHEMBL3301610
- Preferred name: ABEMACICLIB
- Molecule type: Small molecule
- Max clinical phase: 4
- Molecular weight: 506.61
- Heavy atoms: 37
- Hydrogen bond donors: 1
- Hydrogen bond acceptors: 7
- TPSA: 75
- LogP: 4.94
- Rotatable bonds: 7
- Ring count: 5
- Aromatic rings: 4
- Formal charge: 0
- Fraction Csp3: 0.41
- QED: 0.38

## Molecule Similarity
- Weighted Tanimoto: 0.54

Answer: 7.09