Isolation, Chemical Profile and Antimalarial Activities of Bioactive Compounds from Rauvolfia caffra Sond

In this study, the chemical profile of a crude methanol extract of Rauvolfia caffra Sond was determined by ultra-performance liquid chromatography-mass spectrometry (UPLC-MS). Column chromatography and preparative thin layer chromatography were used to isolate three indole alkaloids (raucaffricine, N-methylsarpagine and spegatrine) and one triterpenoid (lupeol). The antiplasmodial activity was determined using the parasite lactate dehydrogenase (pLDH) assay. The UPLC-MS profile of the crude extract reveals that the major constituents of R. caffra are raucaffricine (m/z 513.2) and spegatrine (m/z 352.2). Fraction 3 displayed the highest antiplasmodial activity with an IC(50) of 6.533 μg/mL. However, raucaffricine, isolated from the active fraction did not display any activity. The study identifies the major constituents of R. caffra and also demonstrates that the major constituents do not contribute to the antiplasmodial activity of R. caffra.