DOI: 10.1021/acs.jmedchem.6c01749 ISSN: 0022-2623

Automated High-Throughput Ligand-Detected NMR for Medicinal Chemistry Hit Triage and Binding Assessment

Bradley Falk, Luciano Mueller, Erik Braunstein, Joanne Rivera, Christine Jorge, Purnima Khandelwal, Janet Caceres-Cortes

Abstract

Early discovery campaigns routinely generate screening hits whose progression is limited by uncertain aqueous solubility, chemical integrity, and target engagement. We report a fully automated, ligand-detected high-throughput NMR (HT-NMR) workflow, applicable to aromatic-ring-containing compounds common to high throughput screening libraries, which delivers compound triage and binding assessment. Automated Echo/Tecan sample preparation is validated by Artel calibration and qNMR benchmarking, and band-selective SOFAST experiments centered on the aromatic region enable rapid acquisition in assay buffers. qNMR-SOFAST quantifies aqueous concentrations and flags degradation/impurities, while PE CPMG-SOFAST and STD-SOFAST provide orthogonal target engagement readouts. Python-based tools automate processing, analysis, and reporting. Ligand signals are detected down to 20 μM with quantitation error <25%, allowing binding decisions to be made from as few as four paired samples, <100 μg, per compound. A three-tier decision framework classifies hits by confidence and directs follow-up to orthogonal assays for affinity estimation, accelerating triage and reducing false progression.