Isoacetogenins, Artifacts Issued from Translactonization from Annonaceous Acetogenins

Abstract

m-Extraction of isoacetogenins from &gm~&~cherimolja roots led us to consider these compounds as anifacts obtained by translactonization of 4-hydroxyacetogenins.To confirm this hypothesis, extraction and characterization of initial acetogenins from fresh c ~d e material and effect of alkaloids, basic medium, and alcohol on the kinetic of the translactonization are performed.A mechanism is discussed for this reaction.Cytotoxic activities of isoacetogenins and corresponding acetogenins are evaluated.Over the past six years, studies of several Annonaceae species led to the characterization of 13 biologically active acetogenins belonging to subtype 2 (isoacetogenins).2As part of our continuing investigation of Annonaceae as a source of bioactive agents, we have succeeded in isolation of four isoacetogenins from . . Bonona chenmolla roots.3We present in this paper arguments and experimental data proving that these compounds as well as the previously described isoacetogenins must not be considered as natural products but as artifacts of purification derived from the corresponding 4-hydroxyacetogenins by translactonization4 ; this would he consecutive to the formation of cyclic orthoesten followed by tautomerization involving the hydroxyl group at C-4.