OPERA Model Calculation Details: Bioconcentration Factor

Structural image of L-Homoarginine
Chemical Identifiers
Preferred name: L-Homoarginine
DTXSID: DTXSID70926980
DTXCID: DTXCID001355785
CASRN: 156-86-5
Molecular weight: 188.231
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
2.09 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
0.59
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
= 0.233 ≤ 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:  2.40 L/kg
Predicted: Five fold cross validation prediction for the neighbor
 4.37  L/kg

Structural image of Benzoic acid, 4-(methylamino)-
Benzoic acid, 4-(methylamino)-

 Neighbor: 2
Measured:  1.26 L/kg
Predicted: Five fold cross validation prediction for the neighbor
 1.45  L/kg

Structural image of Pentaerythritol
Pentaerythritol

 Neighbor: 3
Measured:  3.89 L/kg
Predicted: Five fold cross validation prediction for the neighbor
 1.74  L/kg

Structural image of Triethanolamine
Triethanolamine

 Neighbor: 4
Measured:  0.575 L/kg
Predicted: Five fold cross validation prediction for the neighbor
 1.32  L/kg

Structural image of Triisopropanolamine
Triisopropanolamine

 Neighbor: 5
Measured:  6.03 L/kg
Predicted: Five fold cross validation prediction for the neighbor
 3.89  L/kg

Structural image of Phenylphosphinic acid
Phenylphosphinic acid