Effect of C-5′-substituted compounds (25 μmol · kg−1 i.p.) on the percentage of parasitemia (A) and the survival rate of mice infected with P. berghei (B). ▾, vehicle; ○, amodiaquine; •, amopyroquine; ▵, 5′-ClPAQ; ▴, tebuquine; □, cycloquine; ■, bis-pyroquine; ▿, pyronaridine.