Table 2. Performance Measures in Predicting Pgp Inhibitors by Using the Data Set of Broccatelli et al10.
method | parameters | accuracy | sensitivity | specificity | κ | coverage |
---|---|---|---|---|---|---|
Traininga | ||||||
v-NN | HC (h = 0.2; d0 = 1.0)b | 0.85 | 0.86 | 0.84 | 0.70 | 1.00 |
v-NN | HA (h = 0.2; d0 = 0.6) | 0.91 | 0.93 | 0.88 | 0.81 | 0.67 |
FLAP/VolSurf+ | 0.88 | 0.84 | 0.91 | 0.75 | 1.00 | |
Internal Test | ||||||
v-NN | HC (h = 0.2; d0 = 1.0) | 0.84 | 0.84 | 0.83 | 0.67 | 1.00 |
v-NN | HA (h = 0.2; d0 = 0.6) | 0.89 | 0.88 | 0.91 | 0.78 | 0.66 |
FLAP/VolSurf+ | 0.85 | 0.82 | 0.87 | 0.69 | 1.00 | |
External Test | ||||||
v-NN | HC (h = 0.2; d0 = 1.0) | 0.76 | 0.81 | 0.67 | 0.48 | 1.00 |
v-NN | HA (h = 0.2; d0 = 0.6) | 0.88 | 0.91 | 0.80 | 0.71 | 0.53 |
FLAP/VolSurf+ | 0.86 | 0.90 | 0.80 | 0.70 | 1.00 | |
Randomized Training Datac | ||||||
v-NN | HC (h = 0.2; d0 = 1.0) | 0.55 | 0.41 | 0.67 | 0.08 | 1.00 |
v-NN | HA (h = 0.2; d0 = 0.6) | 0.53 | 0.41 | 0.67 | 0.08 | 0.67 |
Performance of 10-fold cross validation.
v-NN parameters (smoothing factor, h, and Tanimoto-distance threshold, d0).
Training set compounds for Pgp were randomly assigned as substrates or nonsubstrates.