Indolosesquiterpene alkaloids from the Cameroonian medicinal plant Polyalthia oliveri (Annonaceae)

Three antiplasmodial indolosesquiterpenes derivatives, named 8α-polyveolinone, N-acetyl-8α-polyveolinone and N-acetyl-polyveoline were isolated from Polyalthia oliveri and their structures were elucidated by means of spectroscopic and spectrometry methods. Their absolute configurations were assigned by ab-initio calculation of CD and ORD data and X-ray diffraction analysis.