TABLE 4.

Activities of water-soluble indenoisoquinolines against trypanosomes and L1210 cells

Compound no.	EC50 (μM)			In trypanosomes
	Trypanosomesa	L1210b	Ratioc	% Inhibition of DNA synthesisd	% Cleavable complexese
20	1.5	2.8	1.9	34 ± 4	10 ± 3
21	0.99	4.3	4.3	56 ± 2	7 ± 1
23	0.65	2.6	4.0	44 ± 3	11 ± 1
14	0.35	0.97	2.8	69 ± 5	3 ± 1
13	0.17	0.42	2.5	66 ± 5	12 ± 2
11	0.13	0.51	4.3	67 ± 11	4 ± 2
15	0.12	0.25	2.1	61 ± 3	4 ± 1
12	0.05	0.28	5.6	68 ± 7	3 ± 1

^aData are from Tables 1 and 3.

^bR² values for all dose-response curves were greater than 0.99, and the coefficient of variation for quadruplicate determinations at a given concentration was less than 20%.

^cRatio of EC₅₀ of L1210 and EC₅₀ of trypanosomes. The 95% confidence intervals around the antitrypanosomal and anti-L1210 EC₅₀s did not overlap.

^dPercent inhibition of incorporation of [³H]thymidine into trichloroacetic acid-precipitable counts by a 5 μM concentration of the compound; means ± standard deviations from three independent experiments are shown. Camptothecin at 10 μM (n = 3) yielded 27 ± 5% inhibition.

^ePercentage of total incorporated [³H]thymidine trapped in K-SDS precipitate after treatment with a 5 μM concentration of the compound; data are means ± standard deviations from three independent experiments. Untreated or DMSO-treated cells yielded 17 ± 2% cleavable complexes, a value subtracted from results for drug-treated cells. Camptothecin at 10 μM (n = 5) trapped 61 ± 8% of radiolabeled DNA.