ACTIVITY OF EXTRACTS AND NAPHTHYLISOQUINOLINE ALKALOIDS FROM TRIPHYOPHYLLUM-PELTATUM, ANCISTROCLADUS-ABBREVIATUS AND A-BARTERI AGAINST PLASMODIUM-FALCIPARUM IN-VITRO

Five extracts from the tropical plant species Triphyophyllum peltatum, Ancistrocladus abbreviatus and A. barteri, and six pure naphthylisoqu inoline alkaloids derived from these species have been examined for th eir antiplasmodial activity. These species are well-known in the tradi tional medicine of West Africa and are used for the treatment of fever s, malaria and other diseases. The extracts and alkaloids were tested against the asexual erythrocytic stages of two strains of Plasmodium f alciparum in vitro (K1/chloroquine-resistant and NF 54/64, clone A1A9/ chloroquine-sensitive). Incorporation of H-3-hypoxanthine was measured in the presence of the test substances after 42 hr of incubation at 3 7 degrees. All extracts and three alkaloids displayed activity. The tw o most potent compounds were dioncopeltine A and dioncophylline B. Str ucture-activity considerations indicate two possible criteria for anti plasmodial activity: an R-configuration at C-3 associated with the abs ence of an oxygen substituent at C-6 and the absence of N-methylation.