Table 4.

Cytotoxicity of zardaverine, anagrelide, and analogs in CS242 embryonal rhabdomyosarcoma (ERMS) and HeLa cells.

Compound numbera	CS242 ERMS		HeLa
	IC50 (nM)b	% Viability (max conc)c	IC50 (nM)b
3 (anagrelide)	58 ± 4	34.7 ± 1.5	6 ± 1
1 (zardaverine)	262 ± 15	10.0 ± 0.7	25 ± 3
4 (quazinone)	535 ± 60	56.4 ± 0.8	62 ± 7
13	596 ± 209	12.5 ± 0.0	11 ± 12
21	911 ± 13	9.7 ± 0.8	56 ± 6
17	1,020 ± 54	11.2 ± 0.3	56 ± 11
16	1,020 ± 97	15.3 ± 1.2	43 ± 8
23	1,210 ± 62	22.7 ± 0.4	111 ± 6
12	1,250 ± 148	49.6 ± 1.8	106 ± 14
2 (imazodan)	1,370 ± 460	71.5 ± 1.2	124 ± 6
9	1,430 ± 99	15.6 ± 1.3	167 ± 9
20	2,100 ± 220	31.1 ± 0.8	183 ± 32
14	2,160 ± 646	58.6 ± 2.3	99 ± 22
19	2,570 ± 308	40.9 ± 1.4	150 ± 17
6	2,810 ± 224	53.0 ± 1.3	289 ± 11
11	3,420 ± 111	41.2 ± 1.0	289 ± 25
10	3,980 ± 515	30.2 ± 0.1	384 ± 52
18	5,180 ± 1,480	31.1 ± 19.1	323 ± 29
15	9,560 ± 467	53.3 ± 2.7	866 ± 96
8	17,200 ± 4,200	50.0 ± 0.0	1,260 ± 58
7	29,200 ± 5,040	50.0 ± 0.0	2,010 ± 449
5	40,000 ± 2,110	60.0 ± 0.0	756 ± 88
24	>31,300	96.8 ± 2.1	>31,300
22	>93,800	97.2 ± 1.8	>93,800

^aNumbers correspond to structures shown in Figure 3.

^bData represent mean ± SD (n = 3).

^cData represent % viability at the maximum concentration of compound tested, which was 93,800 nM except in the case of compounds 1, 3, and 4 (18,800 nM), 2 (23,400 nM), and 24 (31,300 nM).