OPERA Model Calculation Details: Bioconcentration Factor

Structural image of 6-Hydroxy-6-(hydroxymethyl)androsta-1,4-diene-3,17-dione
Chemical Identifiers
Preferred name: 6-Hydroxy-6-(hydroxymethyl)androsta-1,4-diene-3,17-dione
DTXSID: DTXSID60857779
DTXCID: DTXCID20808520
CASRN: 184972-11-0
Molecular weight: 330.424
Model Results
Model name: OPERA_BCF
Model source: OPERA2.8
Property name: Bioconcentration Factor
Property description: Bioconcentration factor: the ratio of the chemical concentration in fish as a result of absorption via the respiratory surface to that in water at steady state
Experimental value: Experimental value from OPERA2.8
 N/A
Predicted value: Predicted value from the model
3.55 L/kg
Confidence level:  Confidence level is calculated from the accuracy of the predictions of the five nearest neighbors weighted by their distance to the query chemical
0.535
Combined applicability domain:  Combined applicability domain from multiple AD measures
Inside training set (
Global AD  Global applicability domain via the leverage approach
= 1) but poor local representation (
Local AD index Local applicability domain index is relative to the similarity of the query chemical to its five nearest neighbors from the training set
= 0.366 ≤ 0.4)
Model Performance
Bioconcentration Factor Model Results Histogram of Bioconcentration Factor Data
Weighted kNN model statistics
Training (75%) 5-fold CV (75%) Test (25%)
R2 RMSE Q2 RMSE R2 RMSE
0.85 0.53 0.84 0.55 0.83 0.64

Model summary in QSAR Model Reporting Format (QMRF)

Nearest Neighbors from Model Knowledge Base
Neighbor: 1
Measured:  2.82 L/kg
Predicted: Five fold cross validation prediction for the neighbor
 2.19  L/kg

Structural image of Cycloheximide
Cycloheximide

Neighbor: 2
Measured:  1.00 L/kg
Predicted: Five fold cross validation prediction for the neighbor
 13.2  L/kg

Structural image of Oxydisulfoton
Oxydisulfoton

Neighbor: 3
Measured:  37.2 L/kg
Predicted: Five fold cross validation prediction for the neighbor
 10.5  L/kg

Structural image of Isoprothiolane
Isoprothiolane

Neighbor: 4
Measured:  3.24 L/kg
Predicted: Five fold cross validation prediction for the neighbor
 2.57  L/kg

Structural image of Bromacil
Bromacil

Neighbor: 5
Measured:  1.82 L/kg
Predicted: Five fold cross validation prediction for the neighbor
 12.9  L/kg

Structural image of Phosmet
Phosmet