Fig. 6: Using database searches to determine important reactions for discovery.

Chord diagram showcasing connectivity of two drugs to enumerated amine–acid coupling products. Drug targets lie on the black band, and the exhaustive matrix enumeration products lie on the checkered yellow band. The color of the chord represents the substructure’s frequency of occurrence, ranging from one to greater than ten. a Two disconnections are shown for athamontanolide (28), both into acrylic acid (29) and an amine (30, 31) with new disconnections generated by the current enumeration workflow. b Similarly, noscapine (32) can be disconnected to amine 33 and acid 34, or to alkyl acid 35 and secondary amine 36. c The frequencies of the top 100 most abundant substructure matches in DrugBank are plotted as a histogram, categorized by their elemental makeup. The top three most abundant structures for each group are shown (37–48).