Table 3.

Experimental and estimated activity of individual test set compounds.

Comp no.	IC50 value (μM)		Errorsa	Fit valueb	Activity scalec
	Experimental	Estimated			Experimental	Estimated
1	0.12	0.14	1.2	7.28	+++	+++
2	0.015	0.14	9.6	7.28	++++	+++
3	0.071	0.16	2.3	7.23	++++	+++
4	0.039	0.17	4.2	7.22	++++	+++
5	0.056	0.17	3	7.22	++++	+++
6	0.051	0.17	3.3	7.21	++++	+++
7	0.01	0.0099	−1	8.44	++++	++++
8	0.046	0.028	−1.6	7.99	++++	++++
9	0.094	0.17	1.8	7.21	++++	+++
10	0.28	0.17	−1.7	7.21	+++	+++
11	0.088	0.17	1.9	7.21	++++	+++
12	1	0.17	−6	7.22	+++	+++
13	1	0.17	−5.7	7.2	+++	+++
14	0.49	2	4	6.14	+++	++
15	4.7	5.5	1.2	5.7	++	++
16	3.4	1.9	−1.8	6.16	++	++
17	2.7	1.4	−1.9	6.29	++	++
18	0.39	1.3	3.4	6.32	+++	++
19	21	12	−1.7	5.37	+	+
20	0.81	1.3	1.6	6.34	+++	++
21	2.5	1.3	−2	6.34	++	++
22	0.49	1.4	2.9	6.3	+++	++
23	5.3	0.91	−5.8	6.48	++	+++
24	29	9.2	−3.2	5.48	+	++
25	8.1	22	2.7	5.1	++	+
26	16	22	1.4	5.11	+	+
27	49	8.2	−6	5.53	+	++
28	1.2	1.9	1.6	6.16	++	++
29	49	16	−3	5.22	+	+
30	4.8	8.6	1.8	5.51	++	++
31	3.1	1.9	−1.7	6.17	++	++
32	0.047	0.15	3.2	7.26	++++	+++
33	3.2	0.2	−16	7.15	++	+++

^aError factor calculated as the ratio of the measured activity to the estimated activity; positive value indicates that the estimated IC₅₀ is higher than the experimental IC₅₀; a negative value indicates that the estimated IC₅₀ is lower than the experimental IC₅₀ value.

^bFit value indicates how well the features in the pharmacophore map with the chemical features present in the compound.

^cActivity scale: ++++, IC₅₀ ≤ 0.1 μM (most active); +++, IC₅₀ 0.1 to 1.0 μM (active); ++, IC₅₀ 1.0 to 10.0 μM (moderately active); +, IC₅₀ > 10.0 μM (inactive).