TABLE 2.

Bioactivities of bis-acridine compounds against chloroquine-sensitive (3D7) and -resistant (W2) strains of P. falciparum

Compound	EC50 (nM)a for strain:
	3D7	W2	FcB1Rb
1	618	791	63 ± 10
2	127	180	55 ± 9
3	62	135	61 ± 3
4	105	136
5	121	147
6	125	129
7	790	1085
8	120	319
9	64	112	17 ± 10c
10	310	303
11	716	823
12	598	629	330 ± 59
13	314	341
14	115	124	19 ± 10
15	95	116	57 ± 30
16	61	74
17	29	34
18	62	69
CQ	10	293
QA	11	33

^aCompounds were incubated with synchronous ring stage parasites for 72 h, and survival was quantified relative to DMSO-treated cultures. Compound bioactivity was expressed as EC₅₀, i.e., the effective concentration lethal to 50% of the parasite culture. Standard deviations did not exceed 20% of the means of three independent experiments.

^bData are from reference 17, and values expressed are the means ± standard deviations of the results of at least three experiments.

^cCompound 9 was also tested against P. falciparum strains 3D7, F32a, GP1, FCR3, FCM29, W2, and K1; see reference 17.