Table 2

Observed and predicted IC50 values from computational models for a structurally diverse array of organic cations

CompoundIC50Catalyst PredictionCerius2 PredictionCLog P
μM μM μM
Training Set
 Clonidine0.71  ± 0.083.11.83.08
 TPeA1.8  ± 0.212.23.21
 Chlorpromazine4.3  ± 0.166.42.86.15
 Quinidine5.4  ± 0.224.57.13.24
 TBA6.5  ± 1.51.89.71.09
 Crystal violet7.7  ± 1.9493.16.25
 Pindolol9.7  ± 0.947.64.52-a
 Procainamide14.5  ± 0.838.418.91.00
 1-Methyl-4-phenylpyridinium15.7  ± 1.159325.6−2.31
 Amantadine18.4  ± 2.427325.02.04
 Ranitidine21.7  ± 2.332.411.21.31
 TPrA22  ± 4.17.445.1−1.02
 Nicotine53.2  ± 9.077181.71.97
 1-(2-Hydroxyethyl)quinolinium80.6  ± 3.27367.6−2.32
 Tyramine107  ± 6.7711870.81
 TEA168  ± 25.9720116−3.14
 Thiamine434  ± 31.575702−5.04
 Dopamine487.2  ± 43.3713590.21
 Cyclohexylamine544  ± 19.0761871.41
N 1-Methylnicotinamide1035  ± 58.0720457−5.21
 Histamine3007  ± 27.272017712-a
 Choline3540  ± 24.07205409−4.36
Test Set
 1-(2-Hydroxyethyl)-4-phenylpyridinium16.2  ± 1.48538.3−1.81
 1-Ethyl-4-phenylpyridinium7.1  ± 1.19213.9−1.78
 1-(Phenyl)methyl-4-phenylpyridinium9.3  ± 0.6288.4−0.54
 1-(2-Hydroxyethyl)-3-phenylpyridinium31.1  ± 2.37163.5−1.81
 1-Ethyl-3-phenylpyridinium28.3  ± 4.5719.4−1.78
 1-(Phenyl)methyl-3-phenylpyridinium5.5  ± 0.91411.4−0.54
 1-Ethylquinolinium67.6  ± 11.27521.3−2.29
 1-(Phenyl)methylquinolinium14.3  ± 0.72211.5−1.05

Kinetic parameters were measured against [3H]TEA transport in hOCT1-expressing HeLa cells (mean ± S.E.M.;n = 3 to 5).

    • 2-a The CLogP program was unable to calculate Log P for pindolol and histamine.