Antitumor Cytotoxicity and Stereochemistry of Polyketides fromGoniothalamus amuyon

Abstract
An antitumor cytotoxicity-bioassay directed fractionation and separation of the ethanol extract of Goniothalamus amuyon led to the isolation of three highly cytotoxic polyketides, gigantriocin (1), corossolin (2) and annonacin (3) against three human tumor cell lines. The stereochemistry was proposed on the basis of extensive NMR analysis and biogenetic pathways.