## Endpoint to Predict
- Endpoint scope: assay
- Measurement type: IC50
- Label type: continuous
- Binary semantics: pchembl
- Assay description: Human Atx Enzyme Inhibition Assay: ATX inhibition was measured by a fluorescence quenching assay using a specifically labeled substrate analogue (MR121 substrate). To obtain this MR121 substrate, BOC and TBS protected 6-amino-hexanoic acid (R)-3-({2-[3-(2-{2-[2-(2-amino-ethoxy)-ethoxy]-ethoxy}-ethoxy)-propionylamino]-ethoxy}-hydroxy-phosphoryloxy)-2-hydroxy-propyl ester (Ferguson et al., Org Lett 2006, 8 (10), 2023) was labeled with MR121 fluorophore (CAS 185308-24-1,1-(3-carboxypropyl)-11-ethyl-1,2,3,4,8,9,10,11-octahydro-dipyrido[3,2-b:2′,3′-i]phenoxazin-13-ium) on the free amine of the ethanolamine side and then, after deprotection, subsequently with tryptophan on the side of the aminohexanoic acid.Assay working solutions were made as follows:Assay buffer (50 mM Tris-HCl, 140 mM NaCl, 5 mM KCl, 1 mM CaCl2, 1 mM MgCl2, 0.01% Triton-X-100, pH 8;ATX solution: ATX (human His-tagged) stock solution (1.08 mg/mL in 20 mM bicine, pH 8.5, 0.15 M NaCl, 10% glycerol, 0.3% CHAPS, 0.02% NaN3), diluted to 1.4-2.5× final concentration in assay buffer;MR121 substrate solution: MR121 substrate stock solution (800 μM MR121 substrate in DMSO), diluted to 2-5× final concentration in assay buffer.Test compounds (10 mM stock in DMSO, 8 μL) were obtained in 384 well sample plates (Corning Costar #3655) and diluted with 8 μL DMSO. Row-wise serial dilutions were made by transferring 8 μL cpd solution to the next row up to row O. The compound and control solutions were mixed five times and 2 μL were transferred to 384 well assay plates (Corning Costar #3702). Then, 15 μL of 41.7 nM ATX solution was added (30 nM final concentration), mixed five times and then incubated for 15 minutes at 30° C. 10 μL of MR121 substrate solution was added (1 M final concentration), mixed 30 times and then incubated for 15 minutes at 30° C. Fluorescence was then measured every 2 minutes for 1 hour (Perkin Elmer plate: vision multimode reader); light intensity: 2.5%; exp. time: 1.4 sec, Filter: Fluo_630/690 nm) and IC50 values were calculated from these readouts.
- Target name: Unchecked
- Target type: UNCHECKED

## Reference Molecule A
- Canonical SMILES: O=C(c1cc(OCC2CCOCC2)nc(C2CC2)c1)N1CC2=C(C1)CN(C(=O)N1CCc3c(O)noc3C1)C2
- Properties:
- ChEMBL ID: CHEMBL5784944
- Molecular weight: 535.6
- Heavy atoms: 39
- Hydrogen bond donors: 1
- Hydrogen bond acceptors: 8
- TPSA: 121.47
- LogP: 2.7
- Rotatable bonds: 5
- Ring count: 7
- Aromatic rings: 2
- Formal charge: 0
- Fraction Csp3: 0.57
- QED: 0.58

## Known Reference Result on This Endpoint
- Molecule A clean result: median pChEMBL = 9
- This result is provided as context for predicting Molecule B on the same endpoint.

## Reference Molecule A Other ChEMBL Evidence
- type IC50; relation =; value 1; units nM; pChEMBL 9; comment 966097

## Query Molecule B
- Canonical SMILES: O=C(c1cc(OCC2CCOCC2)nc(C2CC2)c1)N1CC2=C(C1)CN(C(=O)N1CCc3c(n[nH]c3O)C1)C2
- Properties:
- ChEMBL ID: CHEMBL5792917
- Molecular weight: 534.62
- Heavy atoms: 39
- Hydrogen bond donors: 2
- Hydrogen bond acceptors: 7
- TPSA: 124.12
- LogP: 2.44
- Rotatable bonds: 5
- Ring count: 7
- Aromatic rings: 2
- Formal charge: 0
- Fraction Csp3: 0.57
- QED: 0.56

## Molecule Similarity
- Weighted Tanimoto: 0.74

Answer: 6.36