Antiplasmodial sesquiterpenes from the seeds of Salacia longipes var. camerunensis

Abstract Phytochemical investigation of the seeds of Salacia longipes var. camerunensis led to the isolation of four sesquiterpenoid derivatives, salaterpene A ( 1 ) (1 α ,2 β ,8 β -triacetoxy-6 β ,9 β -dibenzoyloxy-4 β -hydroxy-dihydro- β -agarofuran), salaterpene B ( 2 ) (1 α ,2 β ,8 β -triacetoxy-9 β -benzoyloxy-6 β -cinnamoyloxy-4 β -hydroxy-dihydro- β -agarofuran), salaterpene C ( 3 ) (1 α ,2 β -diacetoxy-6 β ,9 β -dibenzoyloxy-4 β -hydroxy-dihydro- β -agarofuran) and salaterpene D ( 4 ) (2 β -acetoxy-1 α ,6 β -dibenzoyloxy-4 β -hydroxy-9 β -nicotinoyloxy-dihydro- β -agarofuran) together with two known compounds ( 5 and 6 ). The structures of the compounds were established by means of NMR spectroscopy. Compounds 1 – 4 and 6 were tested in vitro for their antiplasmodial activity against Plasmodium falciparum chloroquine-resistant strain W2. All the tested compounds exhibited a moderate potency with IC 50 below 2.7 μM.