Antimalarial sesquiterpene lactones from oncosiphon piluliferum

Abstract

With the emergence and spread of drug- resistant parasites, there is a need for new chemically diverse, effective antimalarial drugs. A national multidisciplinary consortium was established to validate scientifically South African medicinal plants for the treatment of malaria. Through this consortium, an indigenous plant, Oncosiphon piluliferum, was identified as a potential source of new antimalarial drugs. Bio-assay-guided fractionation based on in vitro antiplasmodial activity led to the isolation of five sesquiterpene lactones. Spectroscopic techniques and selected derivatisations were applied to fully characterise the compounds. The five compounds and their derivatives were found to possess varying degrees of in vitro antiplasmodial activity against the D10 P. falciparum strain and to possess cytotoxicity against Chinese Hamster Ovarian (CHO) cells