Isolation, characterization and antiplasmodial activity of steroidal alkaloids from Funtumia elastica (Preuss) Stapf

Bioassay-guided fractionation of the EtOH extract of the stem bark of Funtumia elastica resulted in the isolation of four steroidal alkaloids, holarrhetine (1), conessine (2), holarrhesine (3) and isoconessimine (4). Their structures were determined on the basis of 1D- and 2D-NMR techniques and mass spectrometry. Compounds 1–4 exhibited in vitro antiplasmodial activity against the chloroquine-resistant strain FcB1 of Plasmodium falciparum with IC50 values ranging from 0.97 to 3.39 μM. They showed weak cytotoxicity against a rat cell line L-6 with IC50 values ranging from 5.13 to 36.55 μM.

Graphical abstractFour steroidal alkaloids (1–4) were isolated from the stem bark of Funtumia elastica. The antiplasmodial and cytotoxic activities of these compounds are reported.Figure optionsDownload full-size imageDownload as PowerPoint slide