Extending the Record of Bis-γ-pyrone Polypropionates from Marine Pulmonate Mollusks

The isolation and structure elucidation of 10 unreported polypropionate metabolites (compounds <b>6</b>–<b>15</b>), structurally related to either ilikonapyrone (<b>1</b>) or onchidione (<b>3</b>), from two onchidiid pulmonate mollusk species are discussed. Structure elucidation was achieved by NMR spectroscopy and chemical correlation with model compounds. Evaluation of <i>in vitro</i> growth-inhibitory properties in human cancer cells was also carried out on some of the isolated polypropionates including previously reported onchidione metabolites