We collected experimental ADMET data from the published literature. The availability of reliable experimental data and basic structural information is crucial for successful ADMET modeling. PKKB contains 31412 experimental or predicted values for 1685 drug or drug-like molecules. The data in PKKB can be roughly divided into eight categories, i.e. molecular basic information, molecular experimental or predicted physicochemical properties, pharmacology information, and the properties of ADMET (absorption, distribution, metabolism, excretion and toxicity).

Classification Property Measurements
Molecular Properties Molecular weight 1684
logP (experiment) 1019
logP (predicted,AB/logP v2.0) 1625
Pka 638
logD (pH=7,predicted) 1625
Solubility( experiment) 800
logS (predicted,ACD/Labs)(pH=7) 1614
logSw (predicted,AB/LogSw 2.0) 1625
Sw(mg/ml) (predicted,ACD/Labs) 1613
Sw (predicted) 1625
No. of hbond donors 1625
No. of hbond acceptors 1625
No. of rotatable bonds 1625
TPSA 1625
Pharmacology Status 1372
Administration 501
Pharmacology 1543
Absorption Intestinal absorption 679
Absorption(description) 699
Caco-2 64
Human bioavailability 992
Distribution Plasma protein binding 1058
Volume of distribution(Vd) 646
D-blood 66
Metabolism Metabolism 1111
Half-time 1116
Excretion Excretion 855
Urinary excretion 281
Clearance 410
Toxicity Toxicity 873
LD50(rat) 219
LD50(mouse) 243
PKKB’s schema
Human intestinal absorption (HIA)

1. Hou, T.J.; Wang, J.M.; Zhang, W.; Xu, X.J. ADME Evaluation in Drug Discovery. 7. Prediction of Oral Absorption by Correlation and Classification. J. Chem. Inf. Model. 2007, 47, 208-218.

Human bioavailability (F)

1. Tian, S.; Li, Y.Y.; Wang, J.M.; Zhang, J.; Hou, T.J. ADME Evaluation in Drug Discovery. 9. Prediction of Oral Bioavailability in Human based on Molecular Properties and Structural Fingerprints, Molecular Pharmaceutics, 2011, in press.
2. Hou, T.J; Wang, J.M.; Zhang, W.; Xu, X.J. ADME Evaluation in Drug Discovery. 6. Can Oral Bioavailability in Humans Be Effectively Predicted by Simple Molecular Property-Based Rules? J. Chem. Inf. Model. 2007, 47, 460-463.

Caco-2 permeability

1. Hou, T.J.; Zhang, W.; Xia, K.; Xu, X.J. ADME Evaluation in Drug Discovery. 5. Correlation of Caco-2 Permeation with Simple Molecular Properties, Journal of Chemical Information and Computer Sciences, 2004, 44, 1585-1600.

Blood-brain partitioning (logBB)

1. Hou, T.J.; Xu, X.J. ADME Evaluation in Drug Discovery. 3. Modeling Blood-Brain Barrier Partitioning Using Simple Molecular Descriptors. Journal of Chemical Information and Computer Sciences, 2003, 43, 2137-2152.
2. Hou, T.J.; Xu, X.J. ADME Evaluation in Drug Discovery. 1. Applications of Genetic Algorithms on the Prediction of Blood-brain Partitioning of a Large Set of Drugs from Structurally Derived Descriptors, Journal of Molecular Modeling, 2002, 8, 337-349.

P-glycoprotein inhibition

1. Chen, L.; Li, Y.Y.; Zhao, Q.; Peng, H.; Hou, T.J. ADME Evaluation in Drug Discovery. 10. Predictions of P-Glycoprotein Inhibitors using Recursive Partitioning and Naïve Bayesian Classification Techniques, Molecular Pharmaceutics, 2011, (in press)

Solubility (logS)

1. Hou, T.J.; Xia, K.; Zhang, W.; Xu, X.J. ADME Evaluation in Drug Discovery. 4. Prediction of Aqueous Solubility Based on Atom Contribution Approach. Journal of Chemical Information and Modeling, 2004, 44, 266-275.
2. Wang, J.M.; Krudy, G.; Hou, T.J.; Holland, G.; Xu, X.J. Development of Reliable Aqueous Solubility Models and Their Application in Drug-Like Analysis. Journal of Chemical Information and Modeling, 2007, 47, 1395-1404.
3. Wang, J.M.; Hou, T.J.; Xu, X.J. Aqueous Solubility Prediction Based on Weighted Atom Type Counts and Solvent Accessible Surface Areas, Journal of Chemical Information and Modeling, 2009, 49, 571-581.

Other important references

1. Wang, J. M.; Krudy, G.; Xie, X. Q.; Wu, C. D.; Holland, G. Genetic algorithm-optimized QSPR models for bioavailability, protein binding, and urinary excretion. Journal of Chemical Information and Modeling, 2006, 46, 2674-2683.
2. Goodman, L. S.; Gilman, A.; Brunton, L. L.; Teton Data Systems (Firm). Goodman & Gilman's the pharmacological basis of therapeutics.
3. Physicians’ Desk Reference (PDR); Thomson 2005, 59th ed.

We have developed an integrated ADMET database which includes useful information on a variety of important pharmacokinetic and toxic properties. PKKB will be continuously updated as new information becomes available, and we hope it can provide effective help for researchers in the drug discovery field. Moreover, we will afford on-line prediction functions for several important ADMET properties in the next version of PKKB.

Professor Tingjun Hou
Institute of Functional Nano & Soft Materials (FUNSOM),
Soochow University, Suzhou, Jiangsu 215123, China
Email: tjhou@suda.edu.cn

Professor Junmei Wang
Department of Pharmacology,
The University of Texas Southwestern Medical Center,
5323 Harry Hines Blvd., Dallas, TX 75390
Email: Junmei.Wang@UTSouthwestern.edu