Abstract
Bioguided fractionation of Syzygium cumini (Myrtaceae) bark decoction for antiplasmodial activity was performed, leading to the isolation of three known ellagic acid derivatives (ellagic acid, ellagic acid 4-O-α-L-2″-acetylrhamnopyranoside, 3-O-methylellagic acid 3′-O-α-L-rhamnopyranoside), as well as the new derivative 3-O-methylellagic acid 3′-O-β-D-glucopyranoside. Activity investigation was based on the reduction of P. falciparum (PfK1) parasitaemia in vitro and the inhibition of β-hematin formation, a known mechanism of action of some antimalarial drugs. Among the investigated ellagic acid derivatives, only ellagic acid was able to reduce P. falciparum parasitaemia in vitro and inhibit β-hematin formation, suggesting that free hydroxyl groups are necessary for activity within this class of compounds.