In Vitro Antiplasmodial, Antiamoebic, and Cytotoxic Activities of Some Monomeric Isoquinoline Alkaloids

Twenty-one alkaloids have been assessed for activities against Plasmodium falciparum (multidrug- resistant strain K1) in vitro; 18 of these are reported for the first time. Two protoberberine alkaloids, dehydrodiscretine and berberine, were found to have antiplasmodial IC<INF>50</INF> values less than 1 μM, while seven alkaloids&sbd;allocrytopine, columbamine, dehydroocoteine, jatrorrhizine, norcorydine, thalifendine, and ushinsunine&sbd;had values between 1 and 10 μM. These results are discussed in the context of structure−activity relationships. Compounds were also assessed for antiamoebic and cytotoxic activities, but none was significantly active except for berberine, which was moderately cytotoxic.