TABLE 3.

Growth inhibition of C. parvum intracellular forms by lipophilic diaminopyrimidine antifolates

Compound	IC50 (μM)a
I.2	0.6
III.5	0.6
III.6	0.3
IV.4	2
IV.13	2
IV.14	0.6
IV.17	0.3
IV.18	0.2
V.2	0.3
V.5	0.2
V.14	2
V.15	2
V.16	1
VI.6	2
VIII.8	0.6
VIII.9	2

^aIC₅₀s for all other compounds in Fig. 2 and 3 were >3 μM, the highest concentration tested. Concentrations of <0.2 μM were not tested. The assay protocol used was that described in the legend to Fig. 6.