Styryl‐lactones from the stem bark ofGoniothalamus arvensis

The fractionation of the methanolic extract of Goniothalamus arvensis(Annonaceae) stem bark led to the isolation of two novel styryl‐lactones, arvensin and (+)‐2‐epi‐altholactone. The structures of these compounds, which belong to the furano‐pyrone group, were established on the basis of mass spectrometry, one‐ and two‐dimensional nuclear magnetic resonance experiments, as well as simple chemical derivatization. The relative and absolute configurations of the compounds are discussed. Copyright © 1999 John Wiley & Sons, Ltd.