Table 1.
Antimalarial activity and cytotoxicity of selected new tetracyclinesa
| Compound (n) | IC50 for: |
|
|---|---|---|
| Malaria (nM) | Cytotoxicity (μM) | |
| Tetracycline (2) | 330 | >100 |
| Doxycycline (29) | 321 (78) | >50 |
| Minocycline (34) | 102 (49) | >100 |
| MAL0919 (1) | 22 | >100 |
| MAL1570 (4) | 53 (8) | >10 |
| MAL5001 (1) | 28 | >50 |
| MAL5002 (4) | 18 (4) | >50 |
| MAL5003 (2) | 34 | >10 |
| MAL5004 (1) | 46 | >100 |
| MAL5008 (1) | 25 | >100 |
| MAL5011 (1) | 44 | >100 |
| MAL5012 (1) | 37 | >100 |
| MAL5021 (3) | 19 (7) | >50 |
| MAL5022 (1) | 21 | >100 |
| MAL5028 (1) | 27 | >100 |
| MAL5061 (1) | 47 | >10 |
| MAL5064 (2) | 43 | >10 |
| MAL5086 (1) | 26 | >10 |
| MAL5113 (3) | 37 (26) | >10 |
| MAL5155 (4) | 52 (12) | >100 |
| MAL5166 (11) | 21 (7) | >50 |
a
Compound names beginning with MAL are novel compounds. Results, selected from among all active compounds, are means from comparisons of control and treated P. falciparum cultures, assessed by FACS analysis after a 96-h incubation. Values were normalized to percent control activity, and IC50s were calculated by nonlinear regression. n is the number of times antimalarial activity was assayed. Where n is greater than 1, the values shown are means. Where n is greater than 3, the values shown are means (standard deviations). For cytotoxicity, the IC50 indicates the concentration, up to limits of solubility, that killed 50% of COS-1 cells.