Purfalcamine

Purfalcamine has low activity against Toxoplasma gondii calcium-dependent protein kinase 3 (TgCDPK3).
Purfalcamine (225, 450 nM) has no effect on the parasitemia in the first 32 hours. After about 40 hours, parasite level remains stable and then begins dropping.
Purfalcamine inhibits proliferation with EC ₅₀ s of 171-259 nM for P. falciparum strains (3D7, Dd2, FCB, HB3 and W2), which indicate effectiveness against drug-resistant parasites.
Given that the EC ₅₀ value for P. falciparum (3D7) is 230 nM, Purfalcamine shows a therapeutic window ranging from 23-fold to 36-fold (EC ₅₀ s for CHO=12.33 μM, HEp2=7.235 μM, HeLa=7.029 μM and Huh7 =5.476 μM).

Purfalcamine (10 mg/kg; oral gavage; BID; for 6 days) demonstrates a delay in the onset of parasitemia in treated mice.
Purfalcamine (20 mg/kg; orally gavage) exhibits a C _max of 2.6 μM with a half-life of 3.1 hours.