PfPK6-IN-1 is a potent and selective inhibitor of PfPK6 with an IC50 value of 0.3 μM. It inhibits the formation of malarial pigment, affecting the unique heme detoxification pathway specific to the parasite, with an IC50 of 13 μM for β-hematin (βH). PfPK6-IN-1 demonstrates rapid and broad-spectrum antimalarial properties, effective against both sensitive and drug-resistant strains of the parasite. This compound can be utilized in research on antimalarial agents.

PfPK6-IN-1 (Compound 12) exhibits an EC50 of 116 nM against Dd2 asexual blood stage parasites and 210 nM against the Plasmodium falciparum 3D7 strain. As a rapid-acting compound, PfPK6-IN-1 (48 h) shows activity throughout the asexual blood stage cycle, achieving 99.9% parasite clearance within 32.5 hours. In the Dd2 PK6 cKD strain, PfPK6 knockdown does not alter the activity of PfPK6-IN-1, with an EC50 of 129 nM under physiological PK6 levels and 153 nM under knockdown conditions. PfPK6-IN-1 (20-850 nM, 13 months) targets Plasmodium falciparum digestive vacuole transport proteins (PfCRT and PfMDR1), counteracting resistance in the Dd2 strain. When co-administered with chloroquine, PfPK6-IN-1 (0-500 nM, 72 h) demonstrates antagonistic interaction in the 3D7 strain and synergistic interaction in the Dd2 strain. Additionally, PfPK6-IN-1 (0-32 h) inhibits malaria pigment formation by directly inhibiting β-hematin formation in 3D7 strain and increasing the accumulation of toxic hemoglobin in 3D7 parasites. It also exhibits activity against Plasmodium falciparum isolates from Cambodia and Uganda (0-72 h).

PfPK6-IN-1 (Compound 12), administered at a dosage of 15-50 mg/kg either intravenously (i.v.) or intraperitoneally (i.p.), as a single dose or once daily for four consecutive days, can fully prevent infection by P. berghei in mice and partially inhibit existing P. berghei infections.