Fig. 3. Topological features of SpotXplorer0 hits vs. ChEMBL fragments.

a Selection by pharmacophore results in a relatively even distribution of both ring types (Ar: only aromatic—light blue, Mix: both aromatic and non-aromatic—light green, No Ar: non-aromatic—yellow) and both atom types (sp2 hybridization—dark red, vs. sp3 hybridization—light red/salmon). b Overall hydrogen bond distribution of ligands in SpotXplorer0 resulting from pharmacophore matching (HBD: no. of H-bond donors, HBA: no. of H-bond acceptors; 0—dark blue, 1—red, 2—light green, 3—purple, >3—light blue). c Comparison of SpotXplorer0 hit compounds and ChEMBL fragments for selected targets. Each of the targets shown selects non-overlapping ring subsets: 5-HT_1A: mixed ring types with high sp₃ character and few hydrogen bond sites; 5-HT₆: flatter rings, more aromatic character with moderate hydrogen bond site counts; Thrombin: non-aromatic sp₂ rings with higher hydrogen bond site counts (Colors are identical to panels a and b.).