Antiplasmodial activity of a novel diarylheptanoid from Siphonochilus aethiopicus

Abstract

The Nigerian and South African varieties of Siphonochilus aethiopicus were examined for their phytochemical constituents. The ethyl acetate extract of the rhizomes of the South African variety yielded a novel diarylheptanoid, 2,3-diacetoxy-7-(3′′,4′′-dihydroxy-5′′-methoxyphenyl)-1-(4′-hydroxy-3′-methoxyphenyl)-5-heptene and the flavonoid 3,7-dimethoxyquercetin. From the hexane extract of the Nigerian variety, siphonochilone and another flavonoid, 3,4′,7-trimethylkaempferol were isolated. The isolated compounds were characterised by NMR spectroscopic techniques and mass spectrometry. The diarylheptanoid was then assayed for antiplasmodial activity in vitro using a Plasmodium falciparum growth inhibition assay. At the concentrations tested, the compound inhibited parasite growth by 69 − 74%, without producing cytotoxic or significant haemolytic effects. The antiplasmodial activity of the compound is likely mediated by direct mechanism(s) in erythrocytic – stage parasites.

Graphical Abstract

Keywords:

• Wild ginger
• diarylheptanoid
• siphonochilone
• flavonoids
• Nigeria
• South Africa

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The study was also supported in part by an African Academy of Sciences Africa-India Mobility Fund (AIMF-18-004) awarded to Ezenyi IC. The funders had no role in the study design and analysis.