Computational approaches for binding affinity prediction
are most frequently demonstrated through cross-validation within a
series of molecules or through performance shown on a blinded test
set. Here, we show how such a system performs in an iterative, temporal
lead optimization exercise. A series of gyrase inhibitors with known
synthetic order formed the set of molecules that could be selected
for “synthesis.” Beginning with a small number of molecules,
based only on structures and activities, a model was constructed.
Compound selection was done computationally, each time making five
selections based on confident predictions of high activity and five
selections based on a quantitative measure of three-dimensional structural
novelty. Compound selection was followed by model refinement using
the new data. Iterative computational candidate selection produced
rapid improvements in selected compound activity, and incorporation
of explicitly novel compounds uncovered much more diverse active inhibitors
than strategies lacking active novelty selection.