## Endpoint to Predict
- Endpoint scope: assay
- Measurement type: IC50
- Label type: continuous
- Binary semantics: pchembl
- Assay description: Inhibition of HIV Reverse Transcriptase: Recombinant full length HIV-1 Reverse Transcriptase (HIVrt) was purchased from Abcam, catalog #ab63979. The last 385 nucleotide region of the HCV anti-genome complementary to the 5′ untranslated region (c5′UTR) was synthesized using T7 RNA polymerase Megascript kit from Ambion (Cat #AM1333). A DNA oligo served as an internal initiation primer and was purchased from IDT. Unless otherwise specified, reaction samples consisted of 20 nM c5′UTR RNA, 100 nM DNA primer, and 1 nM HIVrt, mixed together in a buffer containing 50 mM Tris pH 7.5, 100 mM KCl, 4 mM dithiothreitol (DTT), and 12.5 mM MgCl2. Reactions were initiated at 30° C. by adding 0.1 μM adenosine triphosphate (dATP), 0.1 μM cytosine triphosphate (dCTP), 1 μM guanosine triphosphate (dGTP), and 0.32 μM 3H-thymidine triphosphate (3H-TTP), in a final volume of 50 μL. After 40-mins incubation, the reaction was terminated by adding 60 μl of chilled 20% (w/v) trichloroacetic acid with 500 μM ATP to precipitate nucleic acids. After incubation at 4° C. for 1 h, the sample underwent filtration on a multiscreen BV 1.2-μm 96-well plate (Millipore). 40 μL Microscint-20 (Perkin Elmer) was added to the well and the counts in the sample were determined by a Trilux Microbeta microplate scintillation reader (Wallac).All data were analyzed with GraphPad Prism. The compound concentration at which the enzyme-catalyzed rate was reduced by 50% (IC50) was calculated by fitting the data to the equation Y=% Min+(% Max−% Min)/(1+X/IC50), where Y corresponds to the percent relative enzyme activity, % Min is the residual relative activity at saturating compound concentration, % Max is the relative maximum enzyme activity, and X corresponds to the compound concentration. The Ki was calculated using the Cheng-Prusoff equation assuming competitive inhibition relative to natural dNTP incorporation: Ki=IC50/(1+[dNTP]/Km), where [dNTP] is the concentration of natural dNTP and Km is the apparent Km for dNTP. The standard HIVrt RNA-dependent DNA polymerization (RdDp) assay was used to determine the IC50 values.
- Target name: Unchecked
- Target type: UNCHECKED

## Reference Molecule A
- Canonical SMILES: C[C@H](Cc1cnn2c(N)ncnc12)OCP(=O)(O)OP(=O)(O)OP(=O)(O)O
- Properties:
- ChEMBL ID: CHEMBL5906616
- Molecular weight: 447.17
- Heavy atoms: 27
- Hydrogen bond donors: 5
- Hydrogen bond acceptors: 10
- TPSA: 228.92
- LogP: 0.02
- Rotatable bonds: 9
- Ring count: 2
- Aromatic rings: 2
- Formal charge: 0
- Fraction Csp3: 0.44
- QED: 0.32

## Known Reference Result on This Endpoint
- Molecule A clean result: median pChEMBL = 6.82
- This result is provided as context for predicting Molecule B on the same endpoint.

## Reference Molecule A Other ChEMBL Evidence
- type IC50; relation =; value 150; units nM; pChEMBL 6.82; comment 1217627

## Query Molecule B
- Canonical SMILES: Nc1ncnn2c(C[C@@H](CF)OCP(=O)(O)OP(=O)(O)OP(=O)(O)O)cnc12
- Properties:
- ChEMBL ID: CHEMBL6011772
- Molecular weight: 465.16
- Heavy atoms: 28
- Hydrogen bond donors: 5
- Hydrogen bond acceptors: 10
- TPSA: 228.92
- LogP: -0.03
- Rotatable bonds: 10
- Ring count: 2
- Aromatic rings: 2
- Formal charge: 0
- Fraction Csp3: 0.44
- QED: 0.29

## Molecule Similarity
- Weighted Tanimoto: 0.47

Answer: 6.82