Abstract:
A series of alkylated (bis)urea and (bis)thiourea polyamine analogues were synthesized
and screened for antimalarial activity against chloroquine-sensitive and -resistant strains of Plasmodium
falciparum in vitro. All analogues showed growth inhibitory activity against P. falciparum at less than 3
μM, with the majority having effective IC50 values in the 100-650 nM range. Analogues arrested
parasitic growth within 24 hours of exposure due to a block in nuclear division and therefore asexual
development. Moreover, this effect appears to be cytotoxic and highly selective to malaria parasites
(>7000-fold lower IC50 against P. falciparum) and is not reversible by the exogenous addition of
polyamines. With this first report of potent antimalarial activity of polyamine analogues containing 3-7-
3 or 3-6-3 carbon backbones and substituted terminal urea- or thiourea moieties, we propose that these
compounds represent a structurally novel class of antimalarial agents.
