Table 2. Murcko Scaffold Diversity Analysis^a.

	number of compounds (N)	Murcko scaffold (Ns)	cyclic skeletons (Ncsk)	Ns/N	Ncsk/N	Ncsk/Ns
complete	549	239	169	0.435	0.308	0.707
active	148	102	73	0.689	0.493	0.716
intermediate	247	129	99	0.522	0.401	0.767
inactive	154	67	57	0.435	0.37	0.851

^aScaffold diversity is calculated as the proportion of the number of scaffolds to the total number of compounds. In this table, N means the number of total compounds, Ns for the number of Murcko scaffolds, and Ncsk for the number of cyclic skeletons.