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Updated: May 7, 2026

Pharmacophore Modeling for Targets with Extensive Ligand Libraries: A Case Study on SARS-CoV-2 Mpro
Published on: September 26, 2025
Elaborate ligand-based modeling coupled with multiple linear regression and k nearest neighbor QSAR analyses unveiled
Mohammad A Khanfar1, Mutasem O Taha
1Drug Discovery Unit, Department of Pharmaceutical Sciences, Faculty of Pharmacy, The University of Jordan , Amman 11942, Jordan.
Abstract:
The mammalian target of rapamycin (mTOR) has an important role in cell growth, proliferation, and survival. mTOR is frequently hyperactivated in cancer, and therefore, it is a clinically validated target for cancer therapy. In this study, we combined exhaustive pharmacophore modeling and quantitative structure-activity relationship (QSAR) analysis to explore the structural requirements for potent mTOR inhibitors employing 210 known mTOR ligands. Genetic function algorithm (GFA) coupled with k nearest neighbor (kNN) and multiple linear regression (MLR) analyses were employed to build self-consistent and predictive QSAR models based on optimal combinations of pharmacophores and physicochemical descriptors. Successful pharmacophores were complemented with exclusion spheres to optimize their receiver operating characteristic curve (ROC) profiles. Optimal QSAR models and their associated pharmacophore hypotheses were validated by identification and experimental evaluation of several new promising mTOR inhibitory leads retrieved from the National Cancer Institute (NCI) structural database. The most potent hit illustrated an IC50 value of 48 nM.
Insights
This study identifies key structural features for potent mammalian target of rapamycin (mTOR) inhibitors using pharmacophore modeling and QSAR. New mTOR inhibitors were discovered with high potency, offering potential for cancer therapy.
Area of Science:
- Medicinal Chemistry
- Computational Biology
- Oncology
Background:
- Mammalian target of rapamycin (mTOR) is crucial for cell growth and survival.
- mTOR hyperactivation is common in cancer, making it a therapeutic target.
- Developing potent mTOR inhibitors is vital for effective cancer treatment.
Purpose of the Study:
- To explore structural requirements for potent mTOR inhibitors.
- To develop predictive quantitative structure-activity relationship (QSAR) models for mTOR ligands.
- To identify novel mTOR inhibitory leads for cancer therapy.
Main Methods:
- Employed pharmacophore modeling and QSAR analysis on 210 known mTOR ligands.
- Utilized genetic function algorithm (GFA), k-nearest neighbor (kNN), and multiple linear regression (MLR).
- Validated models by identifying and testing new inhibitors from the NCI database.
Main Results:
- Developed self-consistent and predictive QSAR models for mTOR inhibitors.
- Optimized pharmacophore hypotheses with exclusion spheres for improved accuracy.
- Identified several new promising mTOR inhibitory leads, with the most potent showing an IC50 of 48 nM.
Conclusions:
- The study successfully elucidated structural requirements for potent mTOR inhibition.
- Validated QSAR models and pharmacophore hypotheses led to the discovery of novel mTOR inhibitors.
- The identified leads demonstrate significant potential for further development in cancer therapy.
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