Structure-activity relationships and modes of action of 9-anilinoacridines against chloroquine-resistant Plasmodium falciparum in vitro.
An in vitro investigation of the structure-activity profiles for a range of 9-anilinoacridines on drug-resistant Plasmodium falciparum is reported. C-3, 6-diamino substitution, low lipophilicity, and high pKa values substantially increased the activities of the 9-anilinoacridines tested. There appeared to be no correlation between DNA binding and antimalarial activity. 3,6-Diamino-1'-amino-9-anilinoacridine (compound 13) was the most active compound tested; it had a 50% inhibitory concentration of 25 nM. In vitro mammalian cell growth assays showed compound 13 to be one of the least cytotoxic 9-anilinoacridines (50% inhibitory concentration, 15 microM). Both compound 13 and the antimalarial drug pyronaridine inhibited the decatenation activity of P. falciparum DNA topoisomerase II at concentrations of 10 and 11 microM, respectively.
Biochemistry Department, Science Faculty, Mahidol University, Bangkok, Thailand.
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D000677:Amsacrine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology / Q000633:toxicity; D000818:Animals; D000962:Antimalarials / Q000737:chemistry / Q000494:pharmacology* / Q000633:toxicity; D002460:Cell Line; D002738:Chloroquine / Q000494:pharmacology* / Q000633:toxicity; D004352:Drug Resistance, Microbial; D006801:Humans; D015458:Leukemia, T-Cell / Q000473:pathology; D010963:Plasmodium falciparum / Q000187:drug effects* / Q000201:enzymology; D013329:Structure-Activity Relationship; D059004:Topoisomerase I Inhibitors; D014407:Tumor Cells, Cultured
D000962:Antimalarials; D059004:Topoisomerase I Inhibitors; D000677:Amsacrine; C022202:9-anilinoacridine; D002738:Chloroquine