Virtual screening of large-scale
chemical libraries has become
increasingly useful for identifying high-quality candidates for drug
discovery. While it is possible to exhaustively screen chemical spaces
that number on the order of billions, indirect combinatorial approaches
are needed to efficiently navigate larger, synthon-based virtual spaces.
We describe Shape-Aware Synthon Search (SASS), a synthon-based virtual
screening method that carries out shape similarity searches in the
synthon space instead of the enumerated product space. SASS can replicate
results from exhaustive searches in ultralarge, combinatorial spaces
with high recall on a variety of query molecules while only scoring
a small subspace of possible enumerated products, thereby significantly
accelerating large-scale, shape-based virtual screening.