Evidence map›Paper›PMID 33430972›Full record

ArticleJournal of cheminformatics2019

Open-source QSAR models for pKa prediction using multiple machine learning approaches.

Kamel Mansouri, Neal F Cariello, Alexandru Korotcov, Valery Tkachenko, Chris M Grulke, Catherine S Sprankle, David Allen, Warren M Casey, Nicole C Kleinstreuer, Antony J Williams

Open access · goldAbstract read
In one paragraph

Article in Journal of cheminformatics, 2019. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 57 papers.

0numbers the graph read from it
0cells of the map it votes in
57citing papers in PubMed
14.8field-weighted citation impact, top 1% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

57 citing papers in PubMed, 179 citations in OpenAlex.

  1. Article
  2. Review
  3. Machine Learning-Driven QSAR Modeling for pKInternational journal of molecular sciences · 2026
    Article
  4. Benchmarking pJournal of chemical information and modeling · 2026
    Article
  5. Article
  6. A High-Performance and Interpretable pMolecules (Basel, Switzerland) · 2026
    Article
  7. Article
  8. Review
  9. Article
  10. Environmental science & technology · 2025
    Review
  11. Experimental Determination of pEnvironmental science & technology letters · 2025
    Article
  12. pEnvironmental science & technology · 2025
    Article
  13. Journal of pharmaceutical analysis · 2025
    Article
  14. Article
  15. Comparative Analysis of pACS omega · 2025
    Article
  16. pKJournal of computational chemistry · 2025
    Article
  17. Article
  18. Article
  19. Article
  20. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

10 authors at 3 institutions in 1 country.

Kamel MansouriIntegrated Laboratory Systems, Inc., P.O. Box 13501, Research Triangle Park, NC, 27709, USA. kmansouri@ils-inc.com.ORCID http://orcid.org/0000-0002-6426-8036
Neal F CarielloIntegrated Laboratory Systems, Inc., P.O. Box 13501, Research Triangle Park, NC, 27709, USA.ORCID http://orcid.org/0000-0001-6135-752X
Alexandru KorotcovScience Data Software LLC, 14914 Bradwill Court, Rockville, MD, 20850, USA.
Valery TkachenkoScience Data Software LLC, 14914 Bradwill Court, Rockville, MD, 20850, USA.
Chris M GrulkeNational Center for Computational Toxicology, U.S. Environmental Protection Agency, 109 T.W. Alexander Dr., Mail Code D143-02, Research Triangle Park, NC, 27709, USA.ORCID http://orcid.org/0000-0001-5606-7560
Catherine S SprankleIntegrated Laboratory Systems, Inc., P.O. Box 13501, Research Triangle Park, NC, 27709, USA.ORCID http://orcid.org/0000-0001-9436-5673
David AllenIntegrated Laboratory Systems, Inc., P.O. Box 13501, Research Triangle Park, NC, 27709, USA.
Warren M CaseyNational Institute of Environmental Health Sciences, P.O. Box 12233, Mail Stop K2-16, Research Triangle Park, NC, 27709, USA.
Nicole C KleinstreuerNational Institute of Environmental Health Sciences, P.O. Box 12233, Mail Stop K2-16, Research Triangle Park, NC, 27709, USA.ORCID http://orcid.org/0000-0002-7914-3682
Antony J WilliamsNational Center for Computational Toxicology, U.S. Environmental Protection Agency, 109 T.W. Alexander Dr., Mail Code D143-02, Research Triangle Park, NC, 27709, USA.ORCID http://orcid.org/0000-0002-2668-4821
Triangle · USEnvironmental Protection Agency · USNational Institute of Environmental Health Sciences · US

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundThe logarithmic acid dissociation constant pKa reflects the ionization of a chemical, which affects lipophilicity, solubility, protein binding, and ability to pass through the plasma membrane. Thus, pKa affects chemical absorption, distribution, metabolism, excretion, and toxicity properties. Multiple proprietary software packages exist for the prediction of pKa, but to the best of our knowledge no free and open-source programs exist for this purpose. Using a freely available data set and three machine learning approaches, we developed open-source models for pKa prediction.

methodsThe experimental strongest acidic and strongest basic pKa values in water for 7912 chemicals were obtained from DataWarrior, a freely available software package. Chemical structures were curated and standardized for quantitative structure-activity relationship (QSAR) modeling using KNIME, and a subset comprising 79% of the initial set was used for modeling. To evaluate different approaches to modeling, several datasets were constructed based on different processing of chemical structures with acidic and/or basic pKas. Continuous molecular descriptors, binary fingerprints, and fragment counts were generated using PaDEL, and pKa prediction models were created using three machine learning methods, (1) support vector machines (SVM) combined with k-nearest neighbors (kNN), (2) extreme gradient boosting (XGB) and (3) deep neural networks (DNN).

resultsThe three methods delivered comparable performances on the training and test sets with a root-mean-squared error (RMSE) around 1.5 and a coefficient of determination (R

conclusionsThis work provides multiple QSAR models to predict the strongest acidic and strongest basic pKas of chemicals, built using publicly available data, and provided as free and open-source software on GitHub.

Indexed as

Chemical 2D descriptorsChemical fingerprintsDataWarriorMachine learningPaDELpKa predictionQSAR

Identifiers

PMID33430972
PMCPMC6749653
OpenAlexW2973634761

What OpenQuestion holds

Textmetadata
LicenceCC BY
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.