Bioassay-guided fractionation of the fruit powder of Graviola (Annona muricata) was continued to be conducted
and yielded three more novel bioactive compounds: C-35 annonaceous acetogenins, muricins M
and N, and C-37 annonaceous acetogenins, muricenin. They all contain a mono-tetrahydrofuran ring and
four hydroxyl groups. The structures were elucidated by spectral methods and chemical modification
after isolation via open column chromatographic separation and HPLC purification. Especially, murices
M and N demonstrated more potent anti-proliferative activities against human prostate cancer PC-3 cells.