Cohibins C and D, Two Important Metabolites in the Biogenesis of Acetogenins from Annona muricata and Annona nutans<SUP>1</SUP><BBR RID="np000061ab00001">

Two new annonaceous acetogenins, cohibins C (<BO>1a</BO>) and D (<BO>1b</BO>), have been isolated by extensive chromatography of a hexane extract of Annona muricata seeds and a cyclohexane extract of Annona nutans root bark. Their structures have been established on the basis of spectral evidence (NMR, MS) and confirmed by chemical transformation into a pair of monotetrahydrofuran (mono-THF) acetogenins. The role of these compounds in the biogenesis of mono-THF acetogenins is discussed.