A New Cytotoxic Glycocerebroside from Rauvolfia macrophylla Stapf.

The present study investigated secondary metabolites from stem bark of a Cameroonian medicinal plant Rauvolfia macrophylla Stapf, and their anti-proliferative activities against human leukaemia cell lines, THP-1 (mouse monocytic leukaemia cell lines) and mouse macrophage cell line Raw264.7 (human macrophage leukaemia cell lines). One new glycocereboside, Rauvocerebroside (1) with six other known compounds,; 11-methoxy-19-epiajmalicine (2), 19-epiajmalicine (3), Sucrose (4), Butulinic acid (6) and Lupeol (7) were isolated. Their structural elucidation was done using 1D and 2D NMR, IR and MS spectroscopy data together with published reviews. Analyses of the cytotoxicity of compounds (1), (2) and (3) displayed good activity of (1) on THP-1 (IC50 20.70 μM) and Raw 264.7 (IC50 26.34 μM) cancer cell lines. Compounds (2) and (3), showed moderate activity on THP-1 cells (IC50 43.23 μM for (2) and 34.25 μM for (3) and a low activity on Raw 264.7 cells. These results suggest that compounds (1), (2) and (3) could be potential anticancer agent.