According to Fragment Structures

Fragment-based drug discovery (FBDD) is particularly well-suited for the identification of lead compounds and functional probes. Fragment molecules can cover a vast chemical space and are more amenable to subsequent structural optimization. Molecular fragments with specific scaffolds can be incorporated into the structures of different drugs, and the structural characteristics of these fragments exhibit a certain correlation with the pharmacological and pharmacodynamic properties of the resulting drugs. Given their great potential in drug design, the use of such fragment molecules may facilitate the discovery of bioactive lead compounds with desirable drug-like properties.