Table 3. Antiproliferative Activities Evaluated on Four Cell Lines: A-375 (Melanoma), A549 (Lung), HCT-116 (Colon), and HL-60 (Leukemia)^a.

	Cytotoxicity (IC50, μM)
	A-375	A549	HCT-116	HL-60
camptothecin	0.013	0.009	0.003	0.035
etoposide	0.24	0.59	>10	0.86
securinine 1	6.1	>10	>10	>10
4h	0.36	2.64	1.66	5.00
4q	1.75	> 10	n. t.	>10
4v	2.82	3.99	2.47	>10
4s	0.17	0.60	0.42	0.42
4r	0.06	0.29	0.34	0.66
4w	0.95	4.4	n.t.	>10

^an.t.: not tested.