Integrating ¹⁹Focused Screening with Make-On-Demand Chemical Spaces for Enhanced Fragment Follow-Up

Fragment-based screening (FBS) is a powerful method to generate hits with desirable chemical properties. Among the biophysical methods, ligand-observed ¹⁹F nuclear magnetic resonance (NMR) is particularly suited for performing FBS. However, hits emerging from FBS can be challenging to follow up on, especially with sparse chemistry resources. Lowering the barrier to follow-up could help unlock the potential of these hits. In this study, we have integrated our established ¹⁹Focused screening platform with the make-on-demand (MoD) spaces to enhance fragment selection and follow-up strategies. The massive size of these spaces provides ample opportunity for analoging. The integration of screening with MoD spaces can ensure expandability of the fragment hits without involving in-house chemistry resources. The screening was performed against Embryonic Ectoderm Development (EED) protein. Fragments were selected by using three different in silico approaches, with different tools and different rationales. Two hit chemotypes were expanded further in the Enamine REAL Space using the chemical space docking tool and free energy perturbation calculation for affinity ranking. The different computational approaches to select molecules from the MoD and the crucial steps during hit selection and follow-up will be discussed.